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Kendrick D, Young B, Mason-Jones AJ, Ilyas N, Achana FA, Cooper NJ, Hubbard SJ, Sutton AJ, Smith S, Wynn P, Mulvaney C, Watson MC, Coupland C. Home safety education and provision of safety equipment for injury prevention (Review). ACTA ACUST UNITED AC 2014; 8:761-939. [PMID: 23877910 DOI: 10.1002/ebch.1911] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND In industrialised countries injuries (including burns, poisoning or drowning) are the leading cause of childhood death and steep social gradients exist in child injury mortality and morbidity. The majority of injuries in pre-school children occur at home but there is little meta-analytic evidence that child home safety interventions reduce injury rates or improve a range of safety practices, and little evidence on their effect by social group. OBJECTIVES We evaluated the effectiveness of home safety education, with or without the provision of low cost, discounted or free equipment (hereafter referred to as home safety interventions), in reducing child injury rates or increasing home safety practices and whether the effect varied by social group. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2009, Issue 2) in The Cochrane Library, MEDLINE (Ovid), EMBASE (Ovid), PsycINFO (Ovid), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Social Sciences Citation Index (SSCI), ISI Web of Science: Conference Proceedings Citation Index- Science (CPCI-S), CINAHL (EBSCO) and DARE (2009, Issue 2) in The Cochrane Library. We also searched websites and conference proceedings and searched the bibliographies of relevant studies and previously published reviews. We contacted authors of included studies as well as relevant organisations. The most recent search for trials was May 2009. SELECTION CRITERIA Randomised controlled trials (RCTs), non-randomised controlled trials and controlled before and after (CBA) studies where home safety education with or without the provision of safety equipment was provided to those aged 19 years and under, and which reported injury, safety practices or possession of safety equipment. DATA COLLECTION AND ANALYSIS Two authors independently assessed study quality and extracted data. We attempted to obtain individual participant level data (IPD) for all included studies and summary data and IPD were simultaneously combined in meta-regressions by social and demographic variables. Pooled incidence rate ratios (IRR) were calculated for injuries which occurred during the studies, and pooled odds ratios were calculated for the uptake of safety equipment or safety practices, with 95% confidence intervals. MAIN RESULTS Ninety-eight studies, involving 2,605,044 people, are included in this review. Fifty-four studies involving 812,705 people were comparable enough to be included in at least one meta-analysis. Thirty-five (65%) studies were RCTs. Nineteen (35%) of the studies included in the meta-analysis provided IPD. There was a lack of evidence that home safety interventions reduced rates of thermal injuries or poisoning. There was some evidence that interventions may reduce injury rates after adjusting CBA studies for baseline injury rates (IRR 0.89, 95% CI 0.78 to 1.01). Greater reductions in injury rates were found for interventions delivered in the home (IRR 0.75, 95% CI 0.62 to 0.91), and for those interventions not providing safety equipment (IRR 0.78, 95% CI 0.66 to 0.92). Home safety interventions were effective in increasing the proportion of families with safe hot tap water temperatures (OR 1.41, 95% CI 1.07 to 1.86), functional smoke alarms (OR 1.81, 95% CI 1.30 to 2.52), a fire escape plan (OR 2.01, 95% CI 1.45 to 2.77), storing medicines (OR 1.53, 95% CI 1.27 to 1.84) and cleaning products (OR 1.55, 95% CI 1.22 to 1.96) out of reach, having syrup of ipecac (OR 3.34, 95% CI 1.50 to 7.44) or poison control centre numbers accessible (OR 3.30, 95% CI 1.70 to 6.39), having fitted stair gates (OR 1.61, 95% CI 1.19 to 2.17), and having socket covers on unused sockets (OR 2.69, 95% CI 1.46 to 4.96). Interventions providing free, low cost or discounted safety equipment appeared to be more effective in improving some safety practices than those interventions not doing so. There was no consistent evidence that interventions were less effective in families whose children were at greater risk of injury. AUTHORS' CONCLUSIONS Home safety interventions most commonly provided as one-to-one, face-to-face education, especially with the provision of safety equipment, are effective in increasing a range of safety practices. There is some evidence that such interventions may reduce injury rates, particularly where interventions are provided at home. Conflicting findings regarding interventions providing safety equipment on safety practices and injury outcomes are likely to be explained by two large studies; one clinic-based study provided equipment but did not reduce injury rates and one school-based study did not provide equipment but did demonstrate a significant reduction in injury rates. There was no consistent evidence that home safety education, with or without the provision of safety equipment, was less effective in those participants at greater risk of injury. Further studies are still required to confirm these findings with respect to injury rates.
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Achana F, Hubbard S, Sutton A, Kendrick D, Cooper N. An exploration of synthesis methods in public health evaluations of interventions concludes that the use of modern statistical methods would be beneficial. J Clin Epidemiol 2013; 67:376-90. [PMID: 24388291 DOI: 10.1016/j.jclinepi.2013.09.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 09/19/2013] [Accepted: 09/25/2013] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To review the methods currently used to synthesize evidence in public health evaluations and demonstrate the availability of more sophisticated approaches. STUDY DESIGN AND SETTING A systematic review of National Institute for Health and Care Excellence (NICE) public health appraisals published between 2006 and 2012 was performed to assess the methods used for the synthesis of effectiveness evidence. The ability of new developments in evidence synthesis methodology to address the challenges and opportunities present in a public health context is demonstrated. RESULTS Nine (23%) of the 39 NICE appraisals included in the review performed pairwise meta-analyses as part of the effectiveness review with one of these also including a network meta-analysis. Of the remainder, 29 (74.4%) presented narrative summaries of the evidence only, and 1 (2.6%) appraisal did not present any review of effectiveness and/or cost-effectiveness evidence. Heterogeneity of outcomes, methods, and interventions were the main reasons given for not pooling the data. Exploration of quantitative synthesis methods shows that pairwise meta-analyses can be extended to incorporate individual participant data (when it is available), extend the number of interventions being compared using a network meta-analysis, and adjust for both subject- and summary-level covariates. All these can contribute to ensuring the analysis answers directly the policy-relevant questions. CONCLUSION More sophisticated methods in evidence synthesis should be considered to make evaluations in public health more useful for decision makers.
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Affiliation(s)
- Felix Achana
- Department of Health Sciences, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Stephanie Hubbard
- Department of Health Sciences, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Alex Sutton
- Department of Health Sciences, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Denise Kendrick
- Division of Primary Care, Community Health Sciences, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nicola Cooper
- Department of Health Sciences, University of Leicester, University Road, Leicester LE1 7RH, UK.
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Copetti M, Fontana A, Graziano G, Veneziani F, Siena F, Scardapane M, Lucisano G, Pellegrini F. Advances in meta-analysis: examples from internal medicine to neurology. Neuroepidemiology 2013; 42:59-67. [PMID: 24356064 DOI: 10.1159/000355433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE We review the state of the art in meta-analysis and data pooling following the evolution of the statistical models employed. METHODS Starting from a classic definition of meta-analysis of published data, a set of apparent antinomies which characterized the development of the meta-analytic tools are reconciled in dichotomies where the second term represents a possible generalization of the first one. Particular attention is given to the generalized linear mixed models as an overall framework for meta-analysis. Bayesian meta-analysis is discussed as a further possibility of generalization for sensitivity analysis and the use of priors as a data augmentation approach. RESULTS We provide relevant examples to underline how the need for adequate methods to solve practical issues in specific areas of research have guided the development of advanced methods in meta-analysis. CONCLUSIONS We show how all the advances in meta-analysis naturally merge into the unified framework of generalized linear mixed models and reconcile apparently conflicting approaches. All these complex models can be easily implemented with the standard commercial software available.
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Affiliation(s)
- Massimiliano Copetti
- Unit of Biostatistics, Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
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Data harmonization and federated analysis of population-based studies: the BioSHaRE project. Emerg Themes Epidemiol 2013; 10:12. [PMID: 24257327 PMCID: PMC4175511 DOI: 10.1186/1742-7622-10-12] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 11/11/2013] [Indexed: 01/08/2023] Open
Abstract
Abstracts
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Van Wart SA, Shoaf SE, Mallikaarjun S, Mager DE. Population-based meta-analysis of furosemide pharmacokinetics. Biopharm Drug Dispos 2013; 35:119-33. [DOI: 10.1002/bdd.1874] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/19/2013] [Accepted: 10/15/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Scott A. Van Wart
- Institute for Clinical Pharmacodynamics; Latham NY USA
- Department of Pharmaceutical Sciences, University at Buffalo; State University of New York; Buffalo NY USA
| | - Susan E. Shoaf
- Otsuka Pharmaceutical Development and Commercialization, Inc.; Rockville MD USA
| | - Suresh Mallikaarjun
- Otsuka Pharmaceutical Development and Commercialization, Inc.; Rockville MD USA
| | - Donald E. Mager
- Department of Pharmaceutical Sciences, University at Buffalo; State University of New York; Buffalo NY USA
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Van Wart SA, Shoaf SE, Mallikaarjun S, Mager DE. Population-based meta-analysis of hydrochlorothiazide pharmacokinetics. Biopharm Drug Dispos 2013; 34:527-39. [PMID: 24123104 DOI: 10.1002/bdd.1863] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 08/31/2013] [Indexed: 11/09/2022]
Abstract
Hydrochlorothiazide (HCTZ) is a thiazide diuretic used for the treatment of hypertension and edema associated with fluid overload conditions such as congestive heart failure (CHF). A population-based meta-analysis approach in NONMEM® was used to develop a PK model to characterize the time-course of HCTZ concentrations in plasma and excretion into the urine for healthy subjects and CHF patients. Data from healthy subjects receiving 100 mg of oral HCTZ were supplemented with additional plasma concentration and urinary excretion versus time data published in the literature following administration of oral HCTZ doses ranging from 10 to 500 mg to healthy subjects or patients with renal failure, CHF or hypertension. A two-compartment model with first-order oral absorption, using a Weibull function, and first-order elimination best described HCTZ PK. Creatinine clearance (CLCR ) was a statistically significant predictor of renal clearance (CLR ). Non-renal clearance was estimated to be 2.44 l/h, CLR was 18.3 l/h and T1/2,α was 1.6 h and T1/2,β was 14.8 h for a typical individual with normal renal function (CLCR = 120 ml/min). However, CLR was reduced to 10.5, 5.47 and 2.70 l/h in mild (CLCR = 80 ml/min), moderate (CLCR = 50 ml/min) and severe (CLCR = 30 ml/min) renal impairment, respectively. Model diagnostics helped to demonstrate that the population PK model reasonably predicts the rate of urinary HCTZ excretion over time using dosing history and estimated CLCR , allowing for the convenient assessment of PK-PD relationships for HCTZ when given alone or in combination with other agents used to treat fluid overload conditions.
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Affiliation(s)
- Scott A Van Wart
- Institute for Clinical Pharmacodynamics, Latham, NY, USA; Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
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Ohlssen D, Price KL, Xia HA, Hong H, Kerman J, Fu H, Quartey G, Heilmann CR, Ma H, Carlin BP. Guidance on the implementation and reporting of a drug safety Bayesian network meta-analysis. Pharm Stat 2013; 13:55-70. [PMID: 24038897 DOI: 10.1002/pst.1592] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 07/03/2013] [Accepted: 08/01/2013] [Indexed: 12/19/2022]
Abstract
The Drug Information Association Bayesian Scientific Working Group (BSWG) was formed in 2011 with a vision to ensure that Bayesian methods are well understood and broadly utilized for design and analysis and throughout the medical product development process, and to improve industrial, regulatory, and economic decision making. The group, composed of individuals from academia, industry, and regulatory, has as its mission to facilitate the appropriate use and contribute to the progress of Bayesian methodology. In this paper, the safety sub-team of the BSWG explores the use of Bayesian methods when applied to drug safety meta-analysis and network meta-analysis. Guidance is presented on the conduct and reporting of such analyses. We also discuss different structural model assumptions and provide discussion on prior specification. The work is illustrated through a case study involving a network meta-analysis related to the cardiovascular safety of non-steroidal anti-inflammatory drugs.
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Affiliation(s)
- David Ohlssen
- Novartis Pharmaceuticals Corporation, East Hanover, NJ, 07936, USA
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58
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Dias S, Sutton AJ, Welton NJ, Ades AE. Evidence synthesis for decision making 3: heterogeneity--subgroups, meta-regression, bias, and bias-adjustment. Med Decis Making 2013; 33:618-40. [PMID: 23804507 PMCID: PMC3704206 DOI: 10.1177/0272989x13485157] [Citation(s) in RCA: 336] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/20/2012] [Indexed: 01/03/2023]
Abstract
In meta-analysis, between-study heterogeneity indicates the presence of effect-modifiers and has implications for the interpretation of results in cost-effectiveness analysis and decision making. A distinction is usually made between true variability in treatment effects due to variation in patient populations or settings and biases related to the way in which trials were conducted. Variability in relative treatment effects threatens the external validity of trial evidence and limits the ability to generalize from the results; imperfections in trial conduct represent threats to internal validity. We provide guidance on methods for meta-regression and bias-adjustment, in pairwise and network meta-analysis (including indirect comparisons), using illustrative examples. We argue that the predictive distribution of a treatment effect in a "new" trial may, in many cases, be more relevant to decision making than the distribution of the mean effect. Investigators should consider the relative contribution of true variability and random variation due to biases when considering their response to heterogeneity. In network meta-analyses, various types of meta-regression models are possible when trial-level effect-modifying covariates are present or suspected. We argue that a model with a single interaction term is the one most likely to be useful in a decision-making context. Illustrative examples of Bayesian meta-regression against a continuous covariate and meta-regression against "baseline" risk are provided. Annotated WinBUGS code is set out in an appendix.
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Affiliation(s)
- Sofia Dias
- School of Social and Community Medicine, University of Bristol, Bristol, UK (SD, NJW, AEA)
| | - Alex J Sutton
- Department of Health Sciences, University of Leicester, Leicester, UK (AJS)
| | - Nicky J Welton
- School of Social and Community Medicine, University of Bristol, Bristol, UK (SD, NJW, AEA)
| | - A E Ades
- School of Social and Community Medicine, University of Bristol, Bristol, UK (SD, NJW, AEA)
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Clinical outcomes of single versus staged hybrid repair for thoracoabdominal aortic aneurysm. J Vasc Surg 2013; 58:1192-200. [PMID: 23810260 DOI: 10.1016/j.jvs.2013.04.061] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 04/29/2013] [Accepted: 04/29/2013] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We investigated the outcomes of hybrid repair of thoracoabdominal aortic aneurysms and performed meta-analyses and meta-regressions to assess whether the number of stages during hybrid repair is associated with mortality. METHODS Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome was 30-day mortality. Secondary outcomes of procedural and clinical success were reported descriptively. Meta-analyses, meta-regressions, and logistic regressions were performed to estimate the odds ratio (OR) describing the association between the staging of the operation and in-hospital death. RESULTS We included 19 studies of 660 patients. Procedures were single-staged in 288 patients and staged in 372. Perioperative mortality ranged from 0% to 44.4%, and spinal cord ischemia ranged from 0% to 15.3%. After a mean follow-up of 26 months (range, 6-88.5 months), the overall mortality was 20.8%. The meta-regression of all studies' summary data (OR, 0.64; 95% confidence interval [CI], 0.19-2.16; P = .45; I(2) = 0.42) and a meta-regression where mortality rates in four studies were stratified by operative staging (OR, 0.57; 95% CI, 0.24-1.36; P = .19; I(2) = 0.38) supported a two-stage procedure but failed to reach statistical significance. Logistic regressions of individual patient data from a single center demonstrated evidence that a staged procedure was safer (adjusted OR, 0.04; 95% CI, 0.00-0.96; P < .05). CONCLUSIONS Hybrid repair of thoracoabdominal aortic aneurysms may reduce early morbidity and mortality even in a group considered high risk for open surgery but still carries risks of perioperative complications. This study suggested advantages to a staged procedure, but statistically significant evidence is lacking. Prospective data are still needed to optimize hybrid repair and best define its role.
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Novielli N, Sutton AJ, Cooper NJ. Meta-analysis of the accuracy of two diagnostic tests used in combination: application to the ddimer test and the wells score for the diagnosis of deep vein thrombosis. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2013; 16:619-28. [PMID: 23796297 DOI: 10.1016/j.jval.2013.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
OBJECTIVES It is standard practice for diagnostic tests to be evaluated against gold standards in isolation. In routine clinical practice, however, it is commonplace for multiple tests to be used before making definitive diagnoses. This article describes a meta-analytic modeling framework developed to estimate the accuracy of the combination of two diagnostic tests, accounting for the likely nonindependence of the tests. METHODS A novel multicomponent framework was developed to synthesize information available on different parameters in the model. This allows data to be included from studies evaluating single tests or both tests. Different likelihoods were specified for the different sources of data and linked by means of common parameters. The framework was applied to evaluate the diagnostic accuracy of the Ddimer test and the Wells score for deep vein thrombosis, and the results were compared with those of a model in which independence of tests was assumed. All models were evaluated by using Bayesian Markov chain Monte Carlo simulation methods. RESULTS The results showed the importance of allowing for the (likely) nonindependence of tests in the meta-analysis model when evaluating a combination of diagnostic tests. The analysis also highlighted the relatively limited impact of those studies that evaluated only one of the two tests of interest. CONCLUSIONS The models developed allowed the assumption of independence between diagnostic tests to be relaxed while combining a broad array of relevant information from disparate studies. The framework also raises questions regarding the utility of studies limited to the evaluation of single diagnostic tests.
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Affiliation(s)
- Nicola Novielli
- Department of Health Sciences, University of Leicester, Leicester, UK
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61
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Debray TPA, Moons KGM, Abo-Zaid GMA, Koffijberg H, Riley RD. Individual participant data meta-analysis for a binary outcome: one-stage or two-stage? PLoS One 2013; 8:e60650. [PMID: 23585842 PMCID: PMC3621872 DOI: 10.1371/journal.pone.0060650] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/01/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND A fundamental aspect of epidemiological studies concerns the estimation of factor-outcome associations to identify risk factors, prognostic factors and potential causal factors. Because reliable estimates for these associations are important, there is a growing interest in methods for combining the results from multiple studies in individual participant data meta-analyses (IPD-MA). When there is substantial heterogeneity across studies, various random-effects meta-analysis models are possible that employ a one-stage or two-stage method. These are generally thought to produce similar results, but empirical comparisons are few. OBJECTIVE We describe and compare several one- and two-stage random-effects IPD-MA methods for estimating factor-outcome associations from multiple risk-factor or predictor finding studies with a binary outcome. One-stage methods use the IPD of each study and meta-analyse using the exact binomial distribution, whereas two-stage methods reduce evidence to the aggregated level (e.g. odds ratios) and then meta-analyse assuming approximate normality. We compare the methods in an empirical dataset for unadjusted and adjusted risk-factor estimates. RESULTS Though often similar, on occasion the one-stage and two-stage methods provide different parameter estimates and different conclusions. For example, the effect of erythema and its statistical significance was different for a one-stage (OR = 1.35, [Formula: see text]) and univariate two-stage (OR = 1.55, [Formula: see text]). Estimation issues can also arise: two-stage models suffer unstable estimates when zero cell counts occur and one-stage models do not always converge. CONCLUSION When planning an IPD-MA, the choice and implementation (e.g. univariate or multivariate) of a one-stage or two-stage method should be prespecified in the protocol as occasionally they lead to different conclusions about which factors are associated with outcome. Though both approaches can suffer from estimation challenges, we recommend employing the one-stage method, as it uses a more exact statistical approach and accounts for parameter correlation.
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Affiliation(s)
- Thomas P A Debray
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
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Bower P, Kontopantelis E, Sutton A, Kendrick T, Richards DA, Gilbody S, Knowles S, Cuijpers P, Andersson G, Christensen H, Meyer B, Huibers M, Smit F, van Straten A, Warmerdam L, Barkham M, Bilich L, Lovell K, Liu ETH. Influence of initial severity of depression on effectiveness of low intensity interventions: meta-analysis of individual patient data. BMJ 2013; 346:f540. [PMID: 23444423 PMCID: PMC3582703 DOI: 10.1136/bmj.f540] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/11/2013] [Indexed: 01/16/2023]
Abstract
OBJECTIVE To assess how initial severity of depression affects the benefit derived from low intensity interventions for depression. DESIGN Meta-analysis of individual patient data from 16 datasets comparing low intensity interventions with usual care. SETTING Primary care and community settings. PARTICIPANTS 2470 patients with depression. INTERVENTIONS Low intensity interventions for depression (such as guided self help by means of written materials and limited professional support, and internet delivered interventions). MAIN OUTCOME MEASURES Depression outcomes (measured with the Beck Depression Inventory or Center for Epidemiologic Studies Depression Scale), and the effect of initial depression severity on the effects of low intensity interventions. RESULTS Although patients were referred for low intensity interventions, many had moderate to severe depression at baseline. We found a significant interaction between baseline severity and treatment effect (coefficient -0.1 (95% CI -0.19 to -0.002)), suggesting that patients who are more severely depressed at baseline demonstrate larger treatment effects than those who are less severely depressed. However, the magnitude of the interaction (equivalent to an additional drop of around one point on the Beck Depression Inventory for a one standard deviation increase in initial severity) was small and may not be clinically significant. CONCLUSIONS The data suggest that patients with more severe depression at baseline show at least as much clinical benefit from low intensity interventions as less severely depressed patients and could usefully be offered these interventions as part of a stepped care model.
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Affiliation(s)
- Peter Bower
- NIHR School for Primary Care Research, Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PL, UK.
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Romero R, Yeo L, Miranda J, Hassan S, Conde-Agudelo A, Chaiworapongsa T. A blueprint for the prevention of preterm birth: vaginal progesterone in women with a short cervix. J Perinat Med 2013; 41:27-44. [PMID: 23314512 PMCID: PMC4151573 DOI: 10.1515/jpm-2012-0272] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 12/07/2012] [Indexed: 12/11/2022]
Abstract
Preterm birth is the leading cause of perinatal morbidity and mortality worldwide, and is the most important challenge to modern obstetrics. A major obstacle has been that preterm birth is treated (implicitly or explicitly) as a single condition. Two thirds of preterm births occur after the spontaneous onset of labor, and the remaining one third after "indicated" preterm birth; however, the causes of spontaneous preterm labor and "indicated" preterm birth are different. Spontaneous preterm birth is a syndrome caused by multiple etiologies, one of which is a decline in progesterone action, which induces cervical ripening. A sonographic short cervix (identified in the midtrimester) is a powerful predictor of spontaneous preterm delivery. Randomized clinical trials and individual patient meta-analyses have shown that vaginal progesterone reduces the rate of preterm delivery at <33 weeks of gestation by 44%, along with the rate of admission to the neonatal intensive care unit, respiratory distress syndrome, requirement for mechanical ventilation, and composite neonatal morbidity/mortality score. There is no evidence that 17-α-hydroxyprogesterone caproate can reduce the rate of preterm delivery in women with a short cervix, and therefore, the compound of choice is natural progesterone (not the synthetic progestin). Routine assessment of the risk of preterm birth with cervical ultrasound coupled with vaginal progesterone for women with a short cervix is cost-effective, and the implementation of such a policy is urgently needed. Vaginal progesterone is as effective as cervical cerclage in reducing the rate of preterm delivery in women with a singleton gestation, history of preterm birth, and a short cervix (<25 mm).
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Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, MD, USA.
| | - Lami Yeo
- Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, and Detroit, Michigan, USA,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA
| | - Jezid Miranda
- Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, and Detroit, Michigan, USA
| | - Sonia Hassan
- Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, and Detroit, Michigan, USA,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA
| | - Agustin Conde-Agudelo
- Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, and Detroit, Michigan, USA
| | - Tinnakorn Chaiworapongsa
- Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, and Detroit, Michigan, USA,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA
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Kern ML, Hampson SE, Goldberg LR, Friedman HS. Integrating prospective longitudinal data: modeling personality and health in the Terman Life Cycle and Hawaii Longitudinal Studies. Dev Psychol 2012; 50:1390-406. [PMID: 23231689 DOI: 10.1037/a0030874] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The present study used a collaborative framework to integrate 2 long-term prospective studies: the Terman Life Cycle Study and the Hawaii Personality and Health Longitudinal Study. Within a 5-factor personality-trait framework, teacher assessments of child personality were rationally and empirically aligned to establish similar factor structures across samples. Comparable items related to adult self-rated health, education, and alcohol use were harmonized, and data were pooled on harmonized items. A structural model was estimated as a multigroup analysis. Harmonized child personality factors were then used to examine markers of physiological dysfunction in the Hawaii sample and mortality risk in the Terman sample. Harmonized conscientiousness predicted less physiological dysfunction in the Hawaii sample and lower mortality risk in the Terman sample. These results illustrate how collaborative, integrative work with multiple samples offers the exciting possibility that samples from different cohorts and ages can be linked together to directly test life span theories of personality and health.
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Donegan S, Williamson P, D'Alessandro U, Garner P, Smith CT. Combining individual patient data and aggregate data in mixed treatment comparison meta-analysis: Individual patient data may be beneficial if only for a subset of trials. Stat Med 2012; 32:914-30. [PMID: 22987606 DOI: 10.1002/sim.5584] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 08/01/2012] [Indexed: 01/03/2023]
Abstract
BACKGROUND Individual patient data (IPD) meta-analysis is the gold standard. Aggregate data (AD) and IPD can be combined using conventional pairwise meta-analysis when IPD cannot be obtained for all relevant studies. We extend the methodology to combine IPD and AD in a mixed treatment comparison (MTC) meta-analysis. METHODS The proposed random-effects MTC models combine IPD and AD for a dichotomous outcome. We study the benefits of acquiring IPD for a subset of trials when assessing the underlying consistency assumption by including treatment-by-covariate interactions in the model. We describe three different model specifications that make increasingly stronger assumptions regarding the interactions. We illustrate the methodology through application to real data sets to compare drugs for treating malaria by using the outcome unadjusted treatment success at day 28. We compare results from AD alone, IPD alone and all data. RESULTS When IPD contributed (i.e. either using IPD alone or combining IPD and AD), the chains converged, and we identified statistically significant regression coefficients for the interactions. Using IPD alone, we were able to compare only three of the six treatments of interest. When models were fitted to AD, the treatment effects and regression coefficients for the interactions were far more imprecise, and the chains did not converge. CONCLUSIONS The models combining IPD and AD encapsulated all available evidence. When exploring interactions, it can be beneficial to obtain IPD for a subset of trials and to combine IPD with additional AD.
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Affiliation(s)
- Sarah Donegan
- Department of Biostatistics, Faculty of Health and Life Sciences, University of Liverpool, Shelley's Cottage, Brownlow Street, Liverpool, L69 3GS, UK.
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Kendrick D, Young B, Mason-Jones AJ, Ilyas N, Achana FA, Cooper NJ, Hubbard SJ, Sutton AJ, Smith S, Wynn P, Mulvaney C, Watson MC, Coupland C. Home safety education and provision of safety equipment for injury prevention. Cochrane Database Syst Rev 2012; 2012:CD005014. [PMID: 22972081 PMCID: PMC9758703 DOI: 10.1002/14651858.cd005014.pub3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND In industrialised countries injuries (including burns, poisoning or drowning) are the leading cause of childhood death and steep social gradients exist in child injury mortality and morbidity. The majority of injuries in pre-school children occur at home but there is little meta-analytic evidence that child home safety interventions reduce injury rates or improve a range of safety practices, and little evidence on their effect by social group. OBJECTIVES We evaluated the effectiveness of home safety education, with or without the provision of low cost, discounted or free equipment (hereafter referred to as home safety interventions), in reducing child injury rates or increasing home safety practices and whether the effect varied by social group. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2009, Issue 2) in The Cochrane Library, MEDLINE (Ovid), EMBASE (Ovid), PsycINFO (Ovid), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Social Sciences Citation Index (SSCI), ISI Web of Science: Conference Proceedings Citation Index- Science (CPCI-S), CINAHL (EBSCO) and DARE (2009, Issue 2) in The Cochrane Library. We also searched websites and conference proceedings and searched the bibliographies of relevant studies and previously published reviews. We contacted authors of included studies as well as relevant organisations. The most recent search for trials was May 2009. SELECTION CRITERIA Randomised controlled trials (RCTs), non-randomised controlled trials and controlled before and after (CBA) studies where home safety education with or without the provision of safety equipment was provided to those aged 19 years and under, and which reported injury, safety practices or possession of safety equipment. DATA COLLECTION AND ANALYSIS Two authors independently assessed study quality and extracted data. We attempted to obtain individual participant level data (IPD) for all included studies and summary data and IPD were simultaneously combined in meta-regressions by social and demographic variables. Pooled incidence rate ratios (IRR) were calculated for injuries which occurred during the studies, and pooled odds ratios were calculated for the uptake of safety equipment or safety practices, with 95% confidence intervals. MAIN RESULTS Ninety-eight studies, involving 2,605,044 people, are included in this review. Fifty-four studies involving 812,705 people were comparable enough to be included in at least one meta-analysis. Thirty-five (65%) studies were RCTs. Nineteen (35%) of the studies included in the meta-analysis provided IPD.There was a lack of evidence that home safety interventions reduced rates of thermal injuries or poisoning. There was some evidence that interventions may reduce injury rates after adjusting CBA studies for baseline injury rates (IRR 0.89, 95% CI 0.78 to 1.01). Greater reductions in injury rates were found for interventions delivered in the home (IRR 0.75, 95% CI 0.62 to 0.91), and for those interventions not providing safety equipment (IRR 0.78, 95% CI 0.66 to 0.92).Home safety interventions were effective in increasing the proportion of families with safe hot tap water temperatures (OR 1.41, 95% CI 1.07 to 1.86), functional smoke alarms (OR 1.81, 95% CI 1.30 to 2.52), a fire escape plan (OR 2.01, 95% CI 1.45 to 2.77), storing medicines (OR 1.53, 95% CI 1.27 to 1.84) and cleaning products (OR 1.55, 95% CI 1.22 to 1.96) out of reach, having syrup of ipecac (OR 3.34, 95% CI 1.50 to 7.44) or poison control centre numbers accessible (OR 3.30, 95% CI 1.70 to 6.39), having fitted stair gates (OR 1.61, 95% CI 1.19 to 2.17), and having socket covers on unused sockets (OR 2.69, 95% CI 1.46 to 4.96).Interventions providing free, low cost or discounted safety equipment appeared to be more effective in improving some safety practices than those interventions not doing so. There was no consistent evidence that interventions were less effective in families whose children were at greater risk of injury. AUTHORS' CONCLUSIONS Home safety interventions most commonly provided as one-to-one, face-to-face education, especially with the provision of safety equipment, are effective in increasing a range of safety practices. There is some evidence that such interventions may reduce injury rates, particularly where interventions are provided at home. Conflicting findings regarding interventions providing safety equipment on safety practices and injury outcomes are likely to be explained by two large studies; one clinic-based study provided equipment but did not reduce injury rates and one school-based study did not provide equipment but did demonstrate a significant reduction in injury rates. There was no consistent evidence that home safety education, with or without the provision of safety equipment, was less effective in those participants at greater risk of injury. Further studies are still required to confirm these findings with respect to injury rates.
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Affiliation(s)
- Denise Kendrick
- Division of Primary Care, University of Nottingham, Nottingham, UK.
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67
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Morton SC, Ellenberg JH. Infusion of statistical science in comparative effectiveness research. Clin Trials 2012; 9:6-12. [PMID: 22334463 DOI: 10.1177/1740774511433044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE We present a general introduction to comparative effectiveness research (CER) from a statistician's viewpoint and focus on how statisticians can contribute to the methodology of CER. CONCLUSIONS The statistical science community needs to determine the priorities for methodological research in CER, in collaboration with our colleagues in the aligned medical fields. CER requires that we apply a new paradigm - a focus on the patient. The emphasis on the patient is driven by patients themselves, the federal government, and private payers, in addition to the fact that there is a rising chronic disease burden that is making patient populations more heterogeneous. The availability of new technology and data sources introduces not only complexity but also opportunity. Statistical scientists should rise to meet these new demands and develop optimal, statistically valid approaches to CER, just as they have in agriculture and clinical trials.
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Affiliation(s)
- Sally C Morton
- Department of Biostatistics, Graduate School of Public Health, Pittsburgh, PA 15261, USA.
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Jansen JP. Network meta-analysis of individual and aggregate level data. Res Synth Methods 2012; 3:177-90. [DOI: 10.1002/jrsm.1048] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 05/28/2012] [Accepted: 05/31/2012] [Indexed: 11/07/2022]
Affiliation(s)
- Jeroen P. Jansen
- MAPI Consultancy; Tufts University School of Medicine; Boston MA 02114 USA
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Saramago P, Sutton AJ, Cooper NJ, Manca A. Mixed treatment comparisons using aggregate and individual participant level data. Stat Med 2012; 31:3516-36. [PMID: 22764016 DOI: 10.1002/sim.5442] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 04/23/2012] [Indexed: 11/06/2022]
Abstract
Mixed treatment comparisons (MTC) extend the traditional pair-wise meta-analytic framework to synthesize information on more than two interventions. Although most MTCs use aggregate data (AD), a proportion of the evidence base might be available at the individual level (IPD). We develop a series of novel Bayesian statistical MTC models to allow for the simultaneous synthesis of IPD and AD, potentially incorporating study and individual level covariates. The effectiveness of different interventions to increase the provision of functioning smoke alarms in households with children was used as a motivating dataset. This included 20 studies (11 AD and 9 IPD), including 11 500 participants. Incorporating the IPD into the network allowed the inclusion of information on subject level covariates, which produced markedly more accurate treatment-covariate interaction estimates than an analysis solely on the AD from all studies. Including evidence at the IPD level in the MTC is desirable when exploring participant level covariates; even when IPD is available only for a fraction of the studies. Such modelling may not only reduce inconsistencies within networks of trials but also assist the estimation of intervention subgroup effects to guide more individualised treatment decisions.
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Affiliation(s)
- Pedro Saramago
- Centre for Health Economics, University of York, York, UK.
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Hansen AV, Strathe AB, Kebreab E, France J, Theil PK. Predicting milk yield and composition in lactating sows: A Bayesian approach1. J Anim Sci 2012; 90:2285-98. [DOI: 10.2527/jas.2011-4788] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- A. V. Hansen
- Department of Animal Science, University of California, Davis 95616
| | - A. B. Strathe
- Department of Animal Science, University of California, Davis 95616
| | - E. Kebreab
- Department of Animal Science, University of California, Davis 95616
| | - J. France
- Centre for Nutrition Modelling, Department of Animal and Poultry Science, University of Guelph, Guelph N1G 2W1, Canada
| | - P. K. Theil
- Department of Animal Science, Faculty of Agricultural Sciences, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
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Saramago P, Manca A, Sutton AJ. Deriving input parameters for cost-effectiveness modeling: taxonomy of data types and approaches to their statistical synthesis. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2012; 15:639-649. [PMID: 22867772 DOI: 10.1016/j.jval.2012.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 01/24/2012] [Accepted: 02/19/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND The evidence base informing economic evaluation models is rarely derived from a single source. Researchers are typically expected to identify and combine available data to inform the estimation of model parameters for a particular decision problem. The absence of clear guidelines on what data can be used and how to effectively synthesize this evidence base under different scenarios inevitably leads to different approaches being used by different modelers. OBJECTIVES The aim of this article is to produce a taxonomy that can help modelers identify the most appropriate methods to use when synthesizing the available data for a given model parameter. METHODS This article developed a taxonomy based on possible scenarios faced by the analyst when dealing with the available evidence. While mainly focusing on clinical effectiveness parameters, this article also discusses strategies relevant to other key input parameters in any economic model (i.e., disease natural history, resource use/costs, and preferences). RESULTS The taxonomy categorizes the evidence base for health economic modeling according to whether 1) single or multiple data sources are available, 2) individual or aggregate data are available (or both), or 3) individual or multiple decision model parameters are to be estimated from the data. References to examples of the key methodological developments for each entry in the taxonomy together with citations to where such methods have been used in practice are provided throughout. CONCLUSIONS The use of the taxonomy developed in this article hopes to improve the quality of the synthesis of evidence informing decision models by bringing to the attention of health economics modelers recent methodological developments in this field.
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Affiliation(s)
- Pedro Saramago
- Centre for Health Economics, University of York, York, UK.
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Debray TPA, Koffijberg H, Vergouwe Y, Moons KGM, Steyerberg EW. Aggregating published prediction models with individual participant data: a comparison of different approaches. Stat Med 2012; 31:2697-712. [PMID: 22733546 DOI: 10.1002/sim.5412] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 03/16/2012] [Indexed: 01/07/2023]
Abstract
During the recent decades, interest in prediction models has substantially increased, but approaches to synthesize evidence from previously developed models have failed to keep pace. This causes researchers to ignore potentially useful past evidence when developing a novel prediction model with individual participant data (IPD) from their population of interest. We aimed to evaluate approaches to aggregate previously published prediction models with new data. We consider the situation that models are reported in the literature with predictors similar to those available in an IPD dataset. We adopt a two-stage method and explore three approaches to calculate a synthesis model, hereby relying on the principles of multivariate meta-analysis. The former approach employs a naive pooling strategy, whereas the latter accounts for within-study and between-study covariance. These approaches are applied to a collection of 15 datasets of patients with traumatic brain injury, and to five previously published models for predicting deep venous thrombosis. Here, we illustrated how the generally unrealistic assumption of consistency in the availability of evidence across included studies can be relaxed. Results from the case studies demonstrate that aggregation yields prediction models with an improved discrimination and calibration in a vast majority of scenarios, and result in equivalent performance (compared with the standard approach) in a small minority of situations. The proposed aggregation approaches are particularly useful when few participant data are at hand. Assessing the degree of heterogeneity between IPD and literature findings remains crucial to determine the optimal approach in aggregating previous evidence into new prediction models.
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Affiliation(s)
- Thomas P A Debray
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
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Murtagh MJ, Demir I, Jenkings KN, Wallace SE, Murtagh B, Boniol M, Bota M, Laflamme P, Boffetta P, Ferretti V, Burton PR. Securing the data economy: translating privacy and enacting security in the development of DataSHIELD. Public Health Genomics 2012; 15:243-53. [PMID: 22722688 DOI: 10.1159/000336673] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Contemporary bioscience is seeing the emergence of a new data economy: with data as its fundamental unit of exchange. While sharing data within this new 'economy' provides many potential advantages, the sharing of individual data raises important social and ethical concerns. We examine ongoing development of one technology, DataSHIELD, which appears to elide privacy concerns about sharing data by enabling shared analysis while not actually sharing any individual-level data. We combine presentation of the development of DataSHIELD with presentation of an ethnographic study of a workshop to test the technology. DataSHIELD produced an application of the norm of privacy that was practical, flexible and operationalizable in researchers' everyday activities, and one which fulfilled the requirements of ethics committees. We demonstrated that an analysis run via DataSHIELD could precisely replicate results produced by a standard analysis where all data are physically pooled and analyzed together. In developing DataSHIELD, the ethical concept of privacy was transformed into an issue of security. Development of DataSHIELD was based on social practices as well as scientific and ethical motivations. Therefore, the 'success' of DataSHIELD would, likewise, be dependent on more than just the mathematics and the security of the technology.
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Affiliation(s)
- M J Murtagh
- Data to Knowledge for Practice, University of Leicester, Leicester, UK.
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Hawkins N, Richardson G, Sutton AJ, Cooper NJ, Griffiths C, Rogers A, Bower P. Surrogates, meta-analysis and cost-effectiveness modelling: a combined analytic approach. HEALTH ECONOMICS 2012; 21:742-756. [PMID: 21796723 DOI: 10.1002/hec.1741] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 02/07/2011] [Accepted: 03/18/2011] [Indexed: 05/28/2023]
Abstract
Estimates of cost-effectiveness analyses are typically obtained either directly from 'trial' based analyses or indirectly via surrogate endpoints in 'model' based analyses. Data from clinical trials that include both surrogate and final endpoints can be used in a joint analysis that combines these two approaches. This joint approach allows the inclusion of information regarding the effects of treatment on surrogate endpoints while relaxing the strong assumption of 'conditional independence' associated with indirect model-based analyses. An example cost-effectiveness analysis of Chronic Disease Self-Management Programme is used to compare the different approaches. It is shown that despite using a common data set, the different analytic approaches produce differing estimates of the cost-effectiveness of the intervention and the value of future research. The paper concludes by discussing the selection of the appropriate analytic approach.
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Affiliation(s)
- Neil Hawkins
- Centre for Health Economics, University of York, Heslington,York, UK.
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75
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Gurrin LC, Turkovic L. COMBINING INDIVIDUAL PARTICIPANT DATA AND SUMMARY STATISTICS FROM BOTH CONTINUOUSLY VALUED AND BINARY VARIABLES TO ESTIMATE REGRESSION PARAMETERS. AUST NZ J STAT 2012. [DOI: 10.1111/j.1467-842x.2012.00647.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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76
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Romero R, Nicolaides K, Conde-Agudelo A, Tabor A, O'Brien JM, Cetingoz E, Da Fonseca E, Creasy GW, Klein K, Rode L, Soma-Pillay P, Fusey S, Cam C, Alfirevic Z, Hassan SS. Vaginal progesterone in women with an asymptomatic sonographic short cervix in the midtrimester decreases preterm delivery and neonatal morbidity: a systematic review and metaanalysis of individual patient data. Am J Obstet Gynecol 2012; 206:124.e1-19. [PMID: 22284156 PMCID: PMC3437773 DOI: 10.1016/j.ajog.2011.12.003] [Citation(s) in RCA: 337] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
OBJECTIVE To determine whether the use of vaginal progesterone in asymptomatic women with a sonographic short cervix (≤ 25 mm) in the midtrimester reduces the risk of preterm birth and improves neonatal morbidity and mortality. STUDY DESIGN Individual patient data metaanalysis of randomized controlled trials. RESULTS Five trials of high quality were included with a total of 775 women and 827 infants. Treatment with vaginal progesterone was associated with a significant reduction in the rate of preterm birth <33 weeks (relative risk [RR], 0.58; 95% confidence interval [CI], 0.42-0.80), <35 weeks (RR, 0.69; 95% CI, 0.55-0.88), and <28 weeks (RR, 0.50; 95% CI, 0.30-0.81); respiratory distress syndrome (RR, 0.48; 95% CI, 0.30-0.76); composite neonatal morbidity and mortality (RR, 0.57; 95% CI, 0.40-0.81); birthweight <1500 g (RR, 0.55; 95% CI, 0.38-0.80); admission to neonatal intensive care unit (RR, 0.75; 95% CI, 0.59-0.94); and requirement for mechanical ventilation (RR, 0.66; 95% CI, 0.44-0.98). There were no significant differences between the vaginal progesterone and placebo groups in the rate of adverse maternal events or congenital anomalies. CONCLUSION Vaginal progesterone administration to asymptomatic women with a sonographic short cervix reduces the risk of preterm birth and neonatal morbidity and mortality.
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Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI, USA
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Epstein D, Sutton A. Modelling correlated clinical outcomes in health technology appraisal. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2011; 14:793-799. [PMID: 21914498 DOI: 10.1016/j.jval.2011.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 04/18/2011] [Accepted: 04/25/2011] [Indexed: 05/31/2023]
Abstract
OBJECTIVES Many clinical treatments have multiple effects that can only be effectively captured on multiple outcome scales. It might be important to understand how these outcomes are correlated to evaluate the effectiveness and cost-effectiveness of treatments in decision models. METHODS The probabilities are estimated that both, one, or neither outcome occurs, given estimates of the marginal probability for each outcome and information about the correlation between them. Methods are shown for different measures of association. Lower and upper bounds for the correlation coefficient are calculated for given values of the marginal probabilities. The approach is illustrated using a simplified decision model based on a recent evaluation of adalimumab, a biologic drug for psoriatic arthritis. RESULTS Assuming the outcomes are positively correlated, the probability of both a skin and arthritis response after adalimumab was estimated to be 0.387 (95% confidence interval 0.210-0.570). The incremental cost-effectiveness ratio (ICER) of adalimumab versus no biologic is £18,500 per quality-adjusted life-year (QALY). The ICER increases to £19,500 per QALY if the responses are independent. CONCLUSION Estimates of ICERs can be sensitive to assumptions about how multiple outcomes are correlated. These assumptions should be explored in univariate and probabilistic sensitivity analyses.
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Affiliation(s)
- David Epstein
- Centre for Health Economics, University of York, York, UK.
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Olliaro P, Vaillant MT. Alternative visual displays of metaanalysis of malaria treatment trials to facilitate translation of research into policy. Diagn Microbiol Infect Dis 2011; 68:422-31. [PMID: 21094426 DOI: 10.1016/j.diagmicrobio.2010.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 03/19/2010] [Accepted: 08/06/2010] [Indexed: 01/22/2023]
Abstract
Typically, metaanalyses show relative effects and heterogeneity, but not absolute effects-an essential element in policy decision. Data obtained through a systematic review of antimalarial treatment trials and virtual trials were used to generate a display that shows and quantifies absolute and relative effects as well as heterogeneity for comparative trials results. A plot of failure rates (with 95% confidence intervals) of the test drug on the y axis against the risk difference (RD) versus the comparator drug on the x axis is proposed; the area is divided into 4 quadrants by a vertical line (no RD) and a horizontal line (maximum tolerated failures, e.g., 10% for antimalarials). This allows identifying where a drug can be used (meeting efficacy requirements) and quantifying differences (versus another treatment option). The area of the polygon connecting the study points expresses heterogeneity. This graphic display is simple to prepare and interpret and combines in 1 graph both measures of absolute treatment effect and difference, as well as heterogeneity. It may complement current methods and provide useful information in policy decision making.
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Affiliation(s)
- Piero Olliaro
- UNICEF/UNDP/WB/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
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Welch V, Tugwell P, Petticrew M, de Montigny J, Ueffing E, Kristjansson B, McGowan J, Benkhalti Jandu M, Wells GA, Brand K, Smylie J. How effects on health equity are assessed in systematic reviews of interventions. Cochrane Database Syst Rev 2010; 2010:MR000028. [PMID: 21154402 PMCID: PMC7391240 DOI: 10.1002/14651858.mr000028.pub2] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Enhancing health equity has now achieved international political importance with endorsement from the World Health Assembly in 2009. The failure of systematic reviews to consider effects on health equity is cited by decision-makers as a limitation to their ability to inform policy and program decisions. OBJECTIVES To systematically review methods to assess effects on health equity in systematic reviews of effectiveness. SEARCH STRATEGY We searched the following databases up to July 2 2010: MEDLINE, PsychINFO, the Cochrane Methodology Register, CINAHL, Education Resources Information Center, Education Abstracts, Criminal Justice Abstracts, Index to Legal Periodicals, PAIS International, Social Services Abstracts, Sociological Abstracts, Digital Dissertations and the Health Technology Assessment Database. We searched SCOPUS to identify articles that cited any of the included studies on October 7 2010. SELECTION CRITERIA We included empirical studies of cohorts of systematic reviews that assessed methods for measuring effects on health inequalities. DATA COLLECTION AND ANALYSIS Data were extracted using a pre-tested form by two independent reviewers. Risk of bias was appraised for included studies according to the potential for bias in selection and detection of systematic reviews. MAIN RESULTS Thirty-four methodological studies were included. The methods used by these included studies were: 1) Targeted approaches (n=22); 2) gap approaches (n=12) and gradient approach (n=1). Gender or sex was assessed in eight out of 34 studies, socioeconomic status in ten studies, race/ethnicity in seven studies, age in seven studies, low and middle income countries in 14 studies, and two studies assessed multiple factors across health inequity may exist.Only three studies provided a definition of health equity. Four methodological approaches to assessing effects on health equity were identified: 1) descriptive assessment of reporting and analysis in systematic reviews (all 34 studies used a type of descriptive method); 2) descriptive assessment of reporting and analysis in original trials (12/34 studies); 3) analytic approaches (10/34 studies); and 4) applicability assessment (11/34 studies). Both analytic and applicability approaches were not reported transparently nor in sufficient detail to judge their credibility. AUTHORS' CONCLUSIONS There is a need for improvement in conceptual clarity about the definition of health equity, describing sufficient detail about analytic approaches (including subgroup analyses) and transparent reporting of judgments required for applicability assessments in order to assess and report effects on health equity in systematic reviews.
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Affiliation(s)
- Vivian Welch
- University of OttawaCentre for Global Health, Institute of Population Health1 Stewart Street, Room 206OttawaOntarioCanadaK1N 6N5
| | - Peter Tugwell
- Ottawa HospitalCentre for Global Health, Institute of Population Health, Department of Medicine1 Stewart StreetOttawaOntarioCanadaK1N 6N5
| | - Mark Petticrew
- London School of Hygiene and Tropical MedicineDepartment of Social & Environmental Health Research, Faculty of Public Health & Policy15‐17 Tavistock PlaceLondonUKWC1H 9SH
| | | | - Erin Ueffing
- University of OttawaCentre for Global Health, Institute of Population Health1 Stewart Street, Room 206OttawaOntarioCanadaK1N 6N5
| | - Betsy Kristjansson
- University of OttawaSchool of Psychology, Faculty of Social SciencesRoom 407C, Montpetit Hall125 UniversityOttawaOntarioCanadaK1N 6N5
| | - Jessie McGowan
- University of OttawaInstitute of Population Health/Ottawa Health Research Institute1 Stewart St. room 206OttawaOntarioCanadaK1N 6N5
| | - Maria Benkhalti Jandu
- University of OttawaCenter for Global Health, Institute of Population Health1 Stewart StreetOttawaONCanadaK1N 6N5
| | - George A Wells
- University of Ottawa Heart InstituteCardiovascular Research Reference CentreRoom H1‐140 Ruskin StreetOttawaOntarioCanadaK1Y 4W7
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Broeze KA, Opmeer BC, van der Veen F, Bossuyt PM, Bhattacharya S, Mol BWJ. Individual patient data meta-analysis: a promising approach for evidence synthesis in reproductive medicine. Hum Reprod Update 2010; 16:561-7. [PMID: 20819831 DOI: 10.1093/humupd/dmq043] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Systematic reviews and accompanying meta-analyses are the cornerstones of evidence-based medicine. Systematic reviews summarize clinical evidence; meta-analyses provide summary estimates of the treatment effect or the diagnostic test accuracy. Although deemed to provide the highest level of evidence, their clinical value is limited as they can only summarize aggregated data. In these meta-analyses the true variability of the treatment effects cannot be explored to the desired extent, because the meta-analyses cannot distinguish between patients with different clinical profiles. Systematic reviews and meta-analyses based on individual patient data (IPD), described as the 'gold standard' for systematic reviews are a promising approach that might overcome these limitations. IPD meta-analyses allow treatment effects and diagnostic accuracy to be estimated at the level of relevant patient subgroups. This enables researchers to investigate the effectiveness of treatment in patients with different profiles. In this article, we address the opportunities of systematic reviews and meta-analyses using IPD in reproductive medicine. We discuss its potential based on three clinical examples: single versus double embryo transfer in IVF, the diagnosis of tubal pathology and the prognostic value of ovarian reserve tests. We propose to show potential advantages of IPD systematic reviews and meta-analyses in providing stratified clinical evidence, which could improve medical care.
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81
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Govan L, Ades AE, Weir CJ, Welton NJ, Langhorne P. Controlling ecological bias in evidence synthesis of trials reporting on collapsed and overlapping covariate categories. Stat Med 2010; 29:1340-56. [PMID: 20191599 DOI: 10.1002/sim.3869] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Meta-analysis of randomized controlled trials based on aggregated data is vulnerable to ecological bias if trial results are pooled over covariates that influence the outcome variable, even when the covariate does not modify the treatment effect, or is not associated with the treatment. This paper shows how, when trial results are aggregated over different levels of covariates, the within-study covariate distribution, and the effects of both covariates and treatments can be simultaneously estimated, and ecological bias reduced. Bayesian Markov chain Monte Carlo methods are used. The method is applied to a mixed treatment comparison evidence synthesis of six alternative approaches to post-stroke inpatient care. Results are compared with a model using only the stratified covariate data available, where each stratum is treated as a separate trial, and a model using fully aggregated data, where no covariate data are used.
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Affiliation(s)
- L Govan
- Robertson Centre for Biostatistics, University of Glasgow, Glasgow, UK.
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82
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Sridaran S, McClintock SK, Syphard LM, Herman KM, Barnwell JW, Udhayakumar V. Anti-folate drug resistance in Africa: meta-analysis of reported dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutant genotype frequencies in African Plasmodium falciparum parasite populations. Malar J 2010; 9:247. [PMID: 20799995 PMCID: PMC2940896 DOI: 10.1186/1475-2875-9-247] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 08/30/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) genes of Plasmodium falciparum are associated with resistance to anti-folate drugs, most notably sulphadoxine-pyrimethamine (SP). Molecular studies document the prevalence of these mutations in parasite populations across the African continent. However, there is no systematic review examining the collective epidemiological significance of these studies. This meta-analysis attempts to: 1) summarize genotype frequency data that are critical for molecular surveillance of anti-folate resistance and 2) identify the specific challenges facing the development of future molecular databases. METHODS This review consists of 220 studies published prior to 2009 that report the frequency of select dhfr and dhps mutations in 31 African countries. Maps were created to summarize the location and prevalence of the highly resistant dhfr triple mutant (N51I, C59R, S108N) genotype and dhps double mutant (A437G and K540E) genotype in Africa. A hierarchical mixed effects logistic regression was used to examine the influence of various factors on reported mutant genotype frequency. These factors include: year and location of study, age and clinical status of sampled population, and reporting conventions for mixed genotype data. RESULTS A database consisting of dhfr and dhps mutant genotype frequencies from all African studies that met selection criteria was created for this analysis. The map illustrates particularly high prevalence of both the dhfr triple and dhps double mutant genotypes along the Kenya-Tanzania border and Malawi. The regression model shows a statistically significant increase in the prevalence of both the dhfr triple and dhps double mutant genotypes in Africa. CONCLUSION Increasing prevalence of the dhfr triple mutant and dhps double mutant genotypes in Africa are consistent with the loss of efficacy of SP for treatment of clinical malaria in most parts of this continent. Continued assessment of the effectiveness of SP for the treatment of clinical malaria and intermittent preventive treatment in pregnancy is needed. The creation of a centralized resistance data network, such as the one proposed by the WorldWide Antimalarial Resistance Network (WWARN), will become a valuable resource for planning timely actions to combat drug resistant malaria.
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Affiliation(s)
- Sankar Sridaran
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton road NE, Mail Stop D-67 Atlanta, GA, 30333, USA.
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83
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Wolfson M, Wallace SE, Masca N, Rowe G, Sheehan NA, Ferretti V, LaFlamme P, Tobin MD, Macleod J, Little J, Fortier I, Knoppers BM, Burton PR. DataSHIELD: resolving a conflict in contemporary bioscience--performing a pooled analysis of individual-level data without sharing the data. Int J Epidemiol 2010; 39:1372-82. [PMID: 20630989 PMCID: PMC2972441 DOI: 10.1093/ije/dyq111] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Contemporary bioscience sometimes demands vast sample sizes and there is often then no choice but to synthesize data across several studies and to undertake an appropriate pooled analysis. This same need is also faced in health-services and socio-economic research. When a pooled analysis is required, analytic efficiency and flexibility are often best served by combining the individual-level data from all sources and analysing them as a single large data set. But ethico-legal constraints, including the wording of consent forms and privacy legislation, often prohibit or discourage the sharing of individual-level data, particularly across national or other jurisdictional boundaries. This leads to a fundamental conflict in competing public goods: individual-level analysis is desirable from a scientific perspective, but is prevented by ethico-legal considerations that are entirely valid. METHODS Data aggregation through anonymous summary-statistics from harmonized individual-level databases (DataSHIELD), provides a simple approach to analysing pooled data that circumvents this conflict. This is achieved via parallelized analysis and modern distributed computing and, in one key setting, takes advantage of the properties of the updating algorithm for generalized linear models (GLMs). RESULTS The conceptual use of DataSHIELD is illustrated in two different settings. CONCLUSIONS As the study of the aetiological architecture of chronic diseases advances to encompass more complex causal pathways-e.g. to include the joint effects of genes, lifestyle and environment-sample size requirements will increase further and the analysis of pooled individual-level data will become ever more important. An aim of this conceptual article is to encourage others to address the challenges and opportunities that DataSHIELD presents, and to explore potential extensions, for example to its use when different data sources hold different data on the same individuals.
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84
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Prudente S, Baratta R, Andreozzi F, Morini E, Farina MG, Nigro A, Copetti M, Pellegrini F, Succurro E, Di Pietrantonio L, Brufani C, Barbetti F, Dallapiccola B, Sesti G, Trischitta V, Frittitta L. TRIB3 R84 variant affects glucose homeostasis by altering the interplay between insulin sensitivity and secretion. Diabetologia 2010; 53:1354-61. [PMID: 20393693 DOI: 10.1007/s00125-010-1749-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 03/04/2010] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS The results of studies on the genetics of complex traits need to be replicated and to reach robust statistical significance before they can be considered as established. We here tried to replicate the previously reported association between the TRIB3 Q84R polymorphism (rs2295490) and glucose homeostasis. METHODS Three samples of Europeans with fasting glucose <7.0 mmol/l were studied. In sample 1 (n=791), the association between TRIB3 Q84R and impaired glucose regulation (IGR; defined as impaired fasting glucose and/or impaired glucose tolerance and/or type 2 diabetes by OGTT) and insulin sensitivity (ISI), and its interplay with early-phase insulin secretion (i.e. disposition index [DI]) were analysed. Sample 2 (n=374) and sample 3 (n=394) were used to replicate the association with IGR and insulin sensitivity (by glucose clamp), respectively. Genotyping was performed by TaqMan allele discrimination. RESULTS R84 carriers were at higher risk of IGR: OR for the additive model 1.54, p=0.004, and 1.63, p=0.027, in samples 1 and 2, respectively. In sample 1, both ISI (p=0.005) and DI (p=0.043) were progressively lower from QQ to QR and RR individuals. A 'triangulation approach' indicated that the association with IGR was mostly mediated by DI rather than by ISI changes (i.e. being the expected ORs 1.51 and 1.25, respectively). In sample 3, glucose disposal was 38.8+/-17.7, 33.8+/-14.4, and 31.6+/-13.3 micromol min(-1)kg(-1), p=0.022, in QQ, QR and RR individuals, respectively. CONCLUSIONS/INTERPRETATION Our data confirm that the TRIB3 R84 variant affects glucose homeostasis and suggest this effect is due to an alteration of the interplay between insulin sensitivity and secretion.
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Affiliation(s)
- S Prudente
- IRCCS Casa Sollievo della Sofferenza Mendel Institute, Viale Regina Margherita 261, 00198 Rome, Italy
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85
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Ahn JE, French JL. Longitudinal aggregate data model-based meta-analysis with NONMEM: approaches to handling within treatment arm correlation. J Pharmacokinet Pharmacodyn 2010; 37:179-201. [DOI: 10.1007/s10928-010-9152-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 03/15/2010] [Indexed: 11/30/2022]
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86
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Riley RD, Steyerberg EW. Meta-analysis of a binary outcome using individual participant data and aggregate data. Res Synth Methods 2010; 1:2-19. [PMID: 26056090 DOI: 10.1002/jrsm.4] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 12/11/2009] [Accepted: 12/19/2009] [Indexed: 11/06/2022]
Abstract
In this paper, we develop meta-analysis models that synthesize a binary outcome from health-care studies while accounting for participant-level covariates. In particular, we show how to synthesize the observed event-risk across studies while accounting for the within-study association between participant-level covariates and individual event probability. The models are adapted for situations where studies provide individual participant data (IPD), or a mixture of IPD and aggregate data. We show that the availability of IPD is crucial in at least some studies; this allows one to model potentially complex within-study associations and separate them from across-study associations, so as to account for potential ecological bias and study-level confounding. The models can produce pertinent population-level and individual-level results, such as the pooled event-risk and the covariate-specific event probability for an individual. Application is made to 14 studies of traumatic brain injury, where IPD are available for four studies and the six-month mortality risk is synthesized in relation to individual age. The results show that as individual age increases the probability of six-month mortality also increases; further, the models reveal clear evidence of ecological bias, with the mean age in each study additionally influencing an individual's mortality probability. Copyright © 2010 John Wiley & Sons, Ltd.
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Affiliation(s)
- Richard D Riley
- Department of Public Health, Epidemiology and Biostatistics, Public Health Building, University of Birmingham, Edgbaston, Birmingham B15 2TT.
| | - Ewout W Steyerberg
- Department of Public Health, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands
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87
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Signorovitch JE, Wu EQ, Yu AP, Gerrits CM, Kantor E, Bao Y, Gupta SR, Mulani PM. Comparative effectiveness without head-to-head trials: a method for matching-adjusted indirect comparisons applied to psoriasis treatment with adalimumab or etanercept. PHARMACOECONOMICS 2010; 28:935-45. [PMID: 20831302 DOI: 10.2165/11538370-000000000-00000] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The absence of head-to-head trials is a common challenge in comparative effectiveness research and health technology assessment. Indirect cross-trial treatment comparisons are possible, but can be biased by cross-trial differences in patient characteristics. Using only published aggregate data, adjustment for such biases may be impossible. Although individual patient data (IPD) would permit adjustment, they are rarely available for all trials. However, many researchers have the opportunity to access IPD for trials of one treatment, a new drug for example, but only aggregate data for trials of comparator treatments. We propose a method that leverages all available data in this setting by adjusting average patient characteristics in trials with IPD to match those reported for trials without IPD. Treatment outcomes, including continuous, categorical and censored time-to-event outcomes, can then be compared across balanced trial populations. The proposed method is illustrated by a comparison of adalimumab and etanercept for the treatment of psoriasis. IPD from trials of adalimumab versus placebo (n = 1025) were re-weighted to match the average baseline characteristics reported for a trial of etanercept versus placebo (n = 330). Re-weighting was based on the estimated propensity of enrolment in the adalimumab versus etanercept trials. Before matching, patients in the adalimumab trials had lower mean age, greater prevalence of psoriatic arthritis, less prior use of systemic treatment or phototherapy, and a smaller mean percentage of body surface area affected than patients in the etanercept trial. After matching, these and all other available baseline characteristics were well balanced across trials. Symptom improvements of ≥75% and ≥90% (as measured by the Psoriasis Area and Severity Index [PASI] score at week 12) were experienced by an additional 17.2% and 14.8% of adalimumab-treated patients compared with the matched etanercept-treated patients (respectively, both p < 0.001). Mean percentage PASI score improvements from baseline were also greater for adalimumab than for etanercept at weeks 4, 8 and 12 (all p < 0.05). Matching adjustment ensured that this indirect comparison was not biased by differences in mean baseline characteristics across trials, supporting the conclusion that adalimumab was associated with significantly greater symptom reduction than etanercept for the treatment of moderate to severe psoriasis.
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88
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Reade MC, Delaney A, Bailey MJ, Harrison DA, Yealy DM, Jones PG, Rowan KM, Bellomo R, Angus DC. Prospective meta-analysis using individual patient data in intensive care medicine. Intensive Care Med 2010; 36:11-21. [PMID: 19760395 PMCID: PMC7079872 DOI: 10.1007/s00134-009-1650-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Accepted: 07/23/2009] [Indexed: 12/25/2022]
Abstract
Meta-analysis is a technique for combining evidence from multiple trials. However, meta-analyses of studies with substantial heterogeneity among patients within trials-common in intensive care-can lead to incorrect conclusions if performed using aggregate data. Use of individual patient data (IPD) can avoid this concern, increase the power of a meta-analysis, and is useful for exploring subgroup effects. Barriers exist to IPD meta-analysis, most of which are overcome if clinical trials are designed to prospectively facilitate the incorporation of their results with other trials. We review the features of prospective IPD meta-analysis and identify those of relevance to intensive care research. We identify three clinical questions, which are the subject of recent or planned randomised controlled trials where IPD MA offers advantages over approaches using aggregate data.
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Affiliation(s)
- Michael C Reade
- CRISMA Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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89
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Bacci S, Di Paola R, Menzaghi C, Di Fulvio P, Di Silvestre S, Pellegrini F, Baratta R, Marucci A, Mastroianno S, Fini G, Formoso G, Consoli A, Perticone F, Frittitta L, Pandolfi A, Trischitta V. ENPP1
Q121 Variant, Increased Pulse Pressure and Reduced Insulin Signaling, and Nitric Oxide Synthase Activity in Endothelial Cells. Arterioscler Thromb Vasc Biol 2009; 29:1678-83. [DOI: 10.1161/atvbaha.109.189191] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
Insulin resistance induces increased pulse pressure (PP), endothelial dysfunction (ED), and reduced bioavailability of endothelium-derived nitric oxide (NO). The genetic background of these 3 cardiovascular risk factors might be partly common. The
ENPP1
K121Q polymorphism is associated with insulin resistance and cardiovascular risk.
Methods and Results—
We investigated whether the K121Q polymorphism is associated with increased PP in white Caucasians and with ED in vitro. In 985 individuals, (390 unrelated and 595 from 248 families), the K121Q polymorphism was associated with PP (
P
=8.0×10
−4
). In the families, the Q121 variant accounted for 0.08 of PP heritability (
P
=9.4×10
−4
). This association was formally replicated in a second sample of 475 individuals (
P
=2.6×10
−2
) but not in 2 smaller samples of 289 and 236 individuals (
P
=0.49 and 0.21, respectively). In the individual patients’ data meta-analysis, comprising 1985 individuals, PP was associated with the Q121 variant (
P
=1.2×10
−3
). Human endothelial cells carrying the KQ genotype showed, as compared to KK cells, reduced insulin-mediated insulin receptor autophosphorylation (
P
=0.03), Ser
473
-Akt phosphorylation (
P
=0.03), and NO synthase activity (
P
=0.003).
Conclusions—
Our data suggest that the
ENPP1
Q121 variant is associated with increased PP in vivo and reduced insulin signaling and ED in vitro, thus indicating a possible pathogenic mechanism for the increased cardiovascular risk observed in
ENPP1
Q121 carriers.
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Affiliation(s)
- Simonetta Bacci
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Rosa Di Paola
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Claudia Menzaghi
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Patrizia Di Fulvio
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Sara Di Silvestre
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Fabio Pellegrini
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Roberto Baratta
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Antonella Marucci
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Sandra Mastroianno
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Grazia Fini
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Gloria Formoso
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Agostino Consoli
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Francesco Perticone
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Lucia Frittitta
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Assunta Pandolfi
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
| | - Vincenzo Trischitta
- From the Endocrine Unit (S.B., S.M.), the Research Unit of Diabetes and Endocrine Diseases (R.D.P., C.M., A.M., G. Fini, V.T.), and the Unit of Biostatistics (F.P.), IRCCS “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; the Departments of Medicine and Aging Sciences (P.D.F., G. Formoso, A.C.) and Biomedical Sciences (S.D.S., A.P.), University “G. d’Annunzio,” Aging Research Center, Ce.S.I., “G. d’Annunzio” University Foundation, Chieti-Pescara, Italy; the Department of Clinical
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Cooper NJ, Sutton AJ, Morris D, Ades AE, Welton NJ. Addressing between-study heterogeneity and inconsistency in mixed treatment comparisons: Application to stroke prevention treatments in individuals with non-rheumatic atrial fibrillation. Stat Med 2009; 28:1861-81. [PMID: 19399825 DOI: 10.1002/sim.3594] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mixed treatment comparison models extend meta-analysis methods to enable comparisons to be made between all relevant comparators in the clinical area of interest. In such modelling it is imperative that potential sources of variability are explored to explain both heterogeneity (variation in treatment effects between trials within pairwise contrasts) and inconsistency (variation in treatment effects between pairwise contrasts) to ensure the validity of the analysis.The objective of this paper is to extend the mixed treatment comparison framework to allow for the incorporation of study-level covariates in an attempt to explain between-study heterogeneity and reduce inconsistency. Three possible model specifications assuming different assumptions are described and applied to a 17-treatment network for stroke prevention treatments in individuals with non-rheumatic atrial fibrillation.The paper demonstrates the feasibility of incorporating covariates within a mixed treatment comparison framework and using model fit statistics to choose between alternative model specifications. Although such an approach may adjust for inconsistencies in networks, as for standard meta-regression, the analysis will suffer from low power if the number of trials is small compared with the number of treatment comparators.
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Affiliation(s)
- Nicola J Cooper
- Department of Health Sciences, University of Leicester, Leicester, U.K.
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91
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Riley RD, Dodd SR, Craig JV, Thompson JR, Williamson PR. Meta-analysis of diagnostic test studies using individual patient data and aggregate data. Stat Med 2009; 27:6111-36. [PMID: 18816508 DOI: 10.1002/sim.3441] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A meta-analysis of diagnostic test studies provides evidence-based results regarding the accuracy of a particular test, and usually involves synthesizing aggregate data (AD) from each study, such as the 2 by 2 tables of diagnostic accuracy. A bivariate random-effects meta-analysis (BRMA) can appropriately synthesize these tables, and leads to clinical results, such as the summary sensitivity and specificity across studies. However, translating such results into practice may be limited by between-study heterogeneity and that they relate to some 'average' patient across studies.In this paper we describe how the meta-analysis of individual patient data (IPD) from diagnostic studies can lead to clinical results more tailored to the individual patient. We develop IPD models that extend the BRMA framework to include study-level covariates, which help explain the between-study heterogeneity, and also patient-level covariates, which allow one to assess the effect of patient characteristics on test accuracy. We show how the inclusion of patient-level covariates requires a careful separation of within-study and across-study accuracy-covariate effects, as the latter are particularly prone to confounding. Our models are assessed through simulation and extended to allow IPD studies to be combined with AD studies, as IPD are not always available for all studies. Application is made to 23 studies assessing the accuracy of ear thermometers for diagnosing fever in children, with 16 IPD and 7 AD studies. The models reveal that between-study heterogeneity is partly explained by the use of different measurement devices, but there is no evidence that being an infant modifies diagnostic accuracy.
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Affiliation(s)
- Richard D Riley
- Faculty of Medicine, Centre for Medical Statistics and Health Evaluation, University of Liverpool, Shelley's Cottage, Liverpool, UK
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92
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Sutton AJ, Cooper NJ, Jones DR. Evidence synthesis as the key to more coherent and efficient research. BMC Med Res Methodol 2009; 9:29. [PMID: 19405972 PMCID: PMC2681473 DOI: 10.1186/1471-2288-9-29] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 04/30/2009] [Indexed: 12/25/2022] Open
Abstract
Background Systematic review and meta-analysis currently underpin much of evidence-based medicine. Such methodologies bring order to previous research, but future research planning remains relatively incoherent and inefficient. Methods To outline a framework for evaluation of health interventions, aimed at increasing coherence and efficiency through i) making better use of information contained within the existing evidence-base when designing future studies; and ii) maximising the information available and thus potentially reducing the need for future studies. Results The framework presented insists that an up-to-date meta-analysis of existing randomised controlled trials (RCTs) should always be considered before future trials are conducted. Such a meta-analysis should inform critical design issues such as sample size determination. The contexts in which the use of individual patient data meta-analysis and mixed treatment comparisons modelling may be beneficial before further RCTs are conducted are considered. Consideration should also be given to how any newly planned RCTs would contribute to the totality of evidence through its incorporation into an updated meta-analysis. We illustrate how new RCTs can have very low power to change inferences of an existing meta-analysis, particularly when between study heterogeneity is taken into consideration. Conclusion While the collation of existing evidence as the basis for clinical practice is now routine, a more coherent and efficient approach to planning future RCTs to strengthen the evidence base needs to be developed. The framework presented is a proposal for how this situation can be improved.
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93
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Kendrick D, Watson MC, Mulvaney CA, Smith SJ, Sutton AJ, Coupland CAC, Mason-Jones AJ. Preventing childhood falls at home: meta-analysis and meta-regression. Am J Prev Med 2008; 35:370-379. [PMID: 18779031 DOI: 10.1016/j.amepre.2008.06.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 04/18/2008] [Accepted: 06/16/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Childhood falls are an important global public health problem, but evidence on their prevention has not been quantitatively synthesized. Despite social inequalities in childhood injury rates, there is a lack of evidence examining the effect of fall-prevention practices by social group. METHODS A systematic review of literature was conducted up to June 2004 and meta-analysis using individual patient data to evaluate the effect of home-safety interventions on fall-prevention practices and fall-injury rates. Meta-regression examined the effect of interventions by child age, gender, and social variables. Included were 21 studies, 13 of which contributed to meta-analyses. RESULTS Home-safety interventions increased stair-gate use (OR=1.26; 95% CI=1.05, 1.51), and there was some evidence of reduced baby-walker use (OR=0.66; 95% CI=0.43, 1.00), but little evidence of increased possession of window locks, screens, or windows with limited opening (OR=1.16, 95% CI=0.84, 1.59) or of nonslip bath mats or decals (OR=1.15; 95% CI=0.51, 2.62). Two studies reported nonsignificant effects on falls (baby-walker-related falls on flat ground [OR=1.35; 95% CI=0.64, 2.83] or down steps or stairs [OR=0.70; 95% CI=0.14, 3.49]) and medically attended falls (OR=0.78; 95% CI=0.61, 1.00). CONCLUSIONS Home-safety education and the provision of safety equipment improved some fall-prevention practices, but the impact on fall-injury rates is unclear. There was some evidence that the effect of home-safety interventions varied by social group.
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Affiliation(s)
- Denise Kendrick
- Division of Primary Care, School of Nursing, University of Nottingham, Hucknall Primary Care Trust, Hucknall Health Centre, Nottingham, England, UK.
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