Reader's guide to critical appraisal of cohort studies: 1. Role and design

Aspirin or enoxaparin for VTE prophylaxis after primary partial, total or revision hip or knee arthroplasty: A secondary analysis from the CRISTAL cluster randomized trial

BACKGROUND

This study compares aspirin to enoxaparin for symptomatic VTE prophylaxis within 90 days of any type of hip or knee arthroplasty performed for any diagnosis, in patients enrolled in the CRISTAL trial.

MATERIALS AND METHODS

CRISTAL was a cluster-randomised crossover, registry-nested non-inferiority trial across 31 hospitals in Australia. The primary publication was restricted to patients undergoing primary total hip or knee arthroplasty for a diagnosis of osteoarthritis. This report includes all enrolled patients undergoing hip or knee arthroplasty procedures (partial or total, primary or revision) performed for any indication. Hospitals were randomized to administer patients aspirin (100mg daily) or enoxaparin (40mg daily), for 35 days after hip arthroplasty and 14 days after knee arthroplasty. Crossover occurred after the patient enrolment target had been met for the first group. The primary outcome was symptomatic VTE within 90 days. Analyses were performed by randomization group.

RESULTS

Between April 20, 2019 and December 18, 2020, 12384 patients were enrolled (7238 aspirin group and 5146 enoxaparin). Of these, 6901 (95.3%) given aspirin and 4827 (93.8%) given enoxaparin (total 11728, 94.7%) were included in the final analyses. Within 90 days, symptomatic VTE occurred in 226 (3.27%) aspirin patients and 85 (1.76%) enoxaparin patients, significant for the superiority of enoxaparin (estimated treatment difference 1.85%, 95% CI 0.59% to 3.10%, p = 0.004). Joint-related reoperation within 90 days was lower in the enoxaparin group (109/4827 (2.26%) vs 171/6896 (2.47%) with aspirin, estimated difference 0.77%; 95% CI 0.06% to 1.47%, p = 0.03). There were no significant differences in the other secondary outcomes.

CONCLUSION

In patients undergoing hip or knee arthroplasty (of any type, performed for any indication) enrolled in the CRISTAL trial, aspirin compared to enoxaparin resulted in a significantly higher rate of symptomatic VTE and joint-related reoperation within 90 days. These findings extend the applicability of the CRISTAL trial results.

TRIAL REGISTRATION

Anzctr.org.au, identifier: ACTRN12618001879257.

Evaluating agreement between evidence from randomised controlled trials and cohort studies in nutrition: a meta-research replication study

This meta-research study aims to evaluate the agreement of effect estimates between bodies of evidence (BoE) from RCTs and cohort studies included in the same nutrition evidence synthesis, to identify factors associated with disagreement, and to replicate the findings of a previous study. We searched Medline, Epistemonikos and the Cochrane Database of Systematic Reviews for nutrition systematic reviews that included both RCTs and cohort studies for the same patient-relevant outcome or intermediate-disease marker. We rated similarity of PI/ECO (population, intervention/exposure, comparison, outcome) between BoE from RCTs and cohort studies. Agreement of effect estimates across BoE was analysed by pooling ratio of risk ratios (RRR) for binary outcomes and difference of standardised mean differences (DSMD) for continuous outcomes. We performed subgroup and sensitivity analyses to explore determinants associated with disagreements. We included 82 BoE-pairs from 51 systematic reviews. For binary outcomes, the RRR was 1.04 (95% confidence interval (CI) 0.99 to 1.10, I2 = 59%, τ2 = 0.02, prediction interval (PI) 0.77 to 1.41). For continuous outcomes, the pooled DSMD was  - 0.09 (95% CI  - 0.26 to 0.09, PI  - 0.55 to 0.38). Subgroup analyses yielded that differences in type of intake/exposure were drivers towards disagreement. We replicated the findings of a previous study, where on average RCTs and cohort studies had similar effect estimates. Disagreement and wide prediction intervals were mainly driven by PI/ECO-dissimilarities. More research is needed to explore other potentially influencing factors (e.g. risk of bias) on the disagreement between effect estimates of both BoE.Trial registration: CRD42021278908.

Assessing the Highest Level of Evidence from Randomized Controlled Trials in Omega-3 Research

Over the years, there has been heightened interest in the health benefits of n-3 polyunsaturated fatty acids (PUFA) in reducing chronic diseases such as, cardiovascular disease (CVD), cancer, type 2 diabetes, and acute macular degeneration (AMD). Due to inconsistent findings in the evidence, a review to critically examine the plethora of evidence from randomized controlled trials (RCTs) in n-3 PUFA research was undertaken. The aim of this review is to study the highest level of evidence and to identify gaps in n-3 PUFA research. RCTs were originally designed for pharmaceutical research and later adopted for nutrition and food-related research. RCTs with active diseases assume that n-3 PUFA will have "drug" like effects, and this high expectation may have led to the inconsistent evidence in the literature. The inconsistency in the literature may be related to varying doses of n-3 PUFA, sources of n-3 PUFA (food vs. supplement; plant vs. marine), type of n-3 PUFA (mixture vs. purified), trial duration, population characteristics, sample size, and genetic variation. For future research, there is a need to distinguish between primary and secondary prevention, and to focus RCTs on primary prevention of chronic diseases by n-3 PUFA which is lacking in the literature.

Zinc and COVID-19: Immunity, Susceptibility, Severity and Intervention

During the coronavirus disease 2019 (COVID-19) pandemic and continuing emergence of viral mutants, there has been a lack of effective treatment methods. Zinc maintains immune function, with direct and indirect antiviral activities. Zinc nutritional status is a critical factor in antiviral immune responses. Importantly, COVID-19 and zinc deficiency overlap in high-risk population. Hence, the potential effect of zinc as a preventive and adjunct therapy for COVID-19 is intriguing. Here, this review summarizes the immune and antiviral function of zinc, the relationship between zinc levels, susceptibility, and severity of COVID-19, and the effect of zinc supplementation on COVID-19. Existing studies have confirmed that zinc deficiency was associated with COVID-19 susceptibility and severity. Zinc supplementation plays a potentially protective role in enhancing immunity, decreasing susceptibility, shortening illness duration, and reducing the severity of COVID-19. We recommend that zinc levels should be monitored, particularly in COVID-19 patients, and zinc as a preventive and adjunct therapy for COVID-19 should be considered for groups at risk of zinc deficiency to reduce susceptibility and disease severity.

Application of Transactional (Cross-lagged panel) Models in Mental Health Research: An Introduction and Review of Methodological Considerations

Transactional models employing cross-lagged panels have been used for over 40 years to examine the longitudinal relations and directional associations between variables of interest to child and adolescent mental health. Through a narrative synthesis of the literature, we provide an accessible overview of cross-lagged panels with attention to developing a research question, study design and assumptions, dynamic effects (including the random-intercept cross-lagged panel model), and reporting and interpretation of results. Implications and critical appraisal guidelines for readers are discussed throughout. Overall, several key points are highlighted, with particular emphasis on the intended level of inference, model and measure selection, and timing of assessments. Despite limitations in establishing causation, cross-lagged panel models are fundamental to non-experimental epidemiologic research in child mental health and development.

Evaluating agreement between bodies of evidence from randomized controlled trials and cohort studies in medical research: a meta-epidemiological study

BACKGROUND

Randomized controlled trials (RCTs) and cohort studies are the most common study design types used to assess the treatment effects of medical interventions. To evaluate the agreement of effect estimates between bodies of evidence (BoE) from randomized controlled trials (RCTs) and cohort studies and to identify factors associated with disagreement.

METHODS

Systematic reviews were published in the 13 medical journals with the highest impact factor identified through a MEDLINE search. BoE-pairs from RCTs and cohort studies with the same medical research question were included. We rated the similarity of PI/ECO (Population, Intervention/Exposure, Comparison, Outcome) between BoE from RCTs and cohort studies. The agreement of effect estimates across BoE was analyzed by pooling ratio of ratios (RoR) for binary outcomes and difference of mean differences for continuous outcomes. We performed subgroup analyses to explore factors associated with disagreements.

RESULTS

One hundred twenty-nine BoE pairs from 64 systematic reviews were included. PI/ECO-similarity degree was moderate: two BoE pairs were rated as "more or less identical"; 90 were rated as "similar but not identical" and 37 as only "broadly similar". For binary outcomes, the pooled RoR was 1.04 (95% CI 0.97-1.11) with considerable statistical heterogeneity. For continuous outcomes, differences were small. In subgroup analyses, degree of PI/ECO-similarity, type of intervention, and type of outcome, the pooled RoR indicated that on average, differences between both BoE were small. Subgroup analysis by degree of PI/ECO-similarity revealed high statistical heterogeneity and wide prediction intervals across PI/ECO-dissimilar BoE pairs.

CONCLUSIONS

On average, the pooled effect estimates between RCTs and cohort studies did not differ. Statistical heterogeneity and wide prediction intervals were mainly driven by PI/ECO-dissimilarities (i.e., clinical heterogeneity) and cohort studies. The potential influence of risk of bias and certainty of the evidence on differences of effect estimates between RCTs and cohort studies needs to be explored in upcoming meta-epidemiological studies.

A systematic review of methodological approaches for evaluating real-world effectiveness of COVID-19 vaccines: Advising resource-constrained settings

Real-world effectiveness studies are important for monitoring performance of COVID-19 vaccination programmes and informing COVID-19 prevention and control policies. We aimed to synthesise methodological approaches used in COVID-19 vaccine effectiveness studies, in order to evaluate which approaches are most appropriate to implement in low- and middle-income countries (LMICs). For this rapid systematic review, we searched PubMed and Scopus for articles published from inception to July 7, 2021, without language restrictions. We included any type of peer-reviewed observational study measuring COVID-19 vaccine effectiveness, for any population. We excluded randomised control trials and modelling studies. All data used in the analysis were extracted from included papers. We used a standardised data extraction form, modified from STrengthening the Reporting of OBservational studies in Epidemiology (STROBE). Study quality was assessed using the REal Life EVidence AssessmeNt Tool (RELEVANT) tool. This study is registered with PROSPERO, CRD42021264658. Our search identified 3,327 studies, of which 42 were eligible for analysis. Most studies (97.5%) were conducted in high-income countries and the majority assessed mRNA vaccines (78% mRNA only, 17% mRNA and viral vector, 2.5% viral vector, 2.5% inactivated vaccine). Thirty-five of the studies (83%) used a cohort study design. Across studies, short follow-up time and limited assessment and mitigation of potential confounders, including previous SARS-CoV-2 infection and healthcare seeking behaviour, were major limitations. This review summarises methodological approaches for evaluating real-world effectiveness of COVID-19 vaccines and highlights the lack of such studies in LMICs, as well as the importance of context-specific vaccine effectiveness data. Further research in LMICs will refine guidance for conducting real-world COVID-19 vaccine effectiveness studies in resource-constrained settings.

Effects of seeking compensation on the psychological health and recovery of injured patients: the role of stress vulnerability and injury-related disability

BACKGROUND

Seeking compensation has been shown to have an adverse effect on the psychological health and recovery of injured patients, however, this effect requires clarification.

METHODS

A total of 2019 adults sustaining a traffic injury were recruited. Of these, 709 (35.1%) lodged a compensation claim. Interviews occurred at 1-, 6- and 12-month post-injury. Outcomes were psychological distress (posttraumatic stress (PTS) and depressive symptoms) and health-related functioning (HrF) (quality of life measured by EQ-5D-3L and disability by WHODAS) over 12-months post-injury. Covariates included individual stress vulnerability (preinjury, injury-related factors).

RESULTS

Compared with non-compensation participants, compensation groups had higher stress vulnerability (more severe injuries and negative reactions) and poorer baseline outcomes (psychological health and HrF). After adjustment, we found an effect of compensation on HrF [β-0.09 (-0.11 to -0.07), p < 0.001] and PTS [β = 0.36 (0.16 to 0.56), p = 0.0003], but not on depression [β = -0.07 (-0.42 to 0.28), p = 0.7]. Both groups improved over time. Vulnerable individuals (β = 1.23, p < 0.001) and those with poorer baseline outcomes (PTS: β = 0.06, p = 0.002; HrF: β = -1.07, p < 0.001) were more likely to lodge a claim. In turn, higher stress vulnerability, poor baseline outcomes and claiming compensation were associated with long-term psychological distress and HrF. Nevertheless, concurrent HrF in the model fully accounted for the compensation effect on psychological distress (β = -0.14, p = 0.27), but not vice versa.

CONCLUSIONS

This study provides convincing evidence that seeking compensation is not necessarily harmful to psychological health. The person's stress vulnerability and injury-related disability emerge as major risk factors of long-term psychological distress, requiring a whole-systems approach to address the problem.

Healthcare Funding Decisions and Real-World Benefits: Reducing Bias by Matching Untreated Patients

Governments and health insurers often make funding decisions based on health gains from randomised controlled trials. These decisions are inherently uncertain because health gains in trials may not translate to practice owing to differences in the population, treatment use and setting. Post-market analysis of real-world data can provide additional evidence but estimates from standard matching methods may be biased when unobserved characteristics explain whether a patient is treated and their outcomes. We propose a new untreated matching approach that can reduce this bias. Our approach utilises the outcomes of contemporaneous untreated patients to improve the matching of treated and historical control patients. We assess the performance of this new approach compared to standard matching using a simulation study and demonstrate the steps required using a funding decision for prostate cancer treatments in Australia. Our simulation study shows that our new matching approach eliminates nearly all bias when unobserved treatment selection is related to outcomes, and outperforms standard matching in most scenarios. In our empirical example, standard matching overestimated survival by 15% (95% confidence interval 2-34) compared to our untreated matching approach. The health gains estimated using our approach were slightly lower than expected based on the trial evidence, but we also found evidence that in practice prescribers ceased prior therapies earlier, treated a more vulnerable population and continued treatment for longer. Our untreated matching approach offers researchers a new tool for reducing uncertainty in healthcare funding decisions using real-world data.

Behavioural activation treatment for depression in individuals with neurological conditions: a systematic review

OBJECTIVE

To evaluate the effectiveness of behavioural activation interventions for people with neurological conditions with comorbid depression, and explore content and adaptations.

DATA SOURCES

PsycINFO, MEDLINE, CINAHL, AMED, and EMBASE databases were searched on the 19 November 2019. Reference lists of selected full-texts were screened by title.

REVIEW METHODS

We included peer-reviewed studies published in English that used behavioural activation for treatment of depression in adults with a neurological condition. Single-case reports, reviews, and grey literature were excluded. Methodological quality was assessed by two authors independently, and quality was appraised using Critical Appraisal Skills Programme checklists.

RESULTS

From 2714 citations, 10 articles were included comprising 590 participants. Behavioural activation was used to treat depression in people with dementia (n = 4), stroke (n = 3), epilepsy (n = 1), Parkinson's disease (n = 1), and brain injury (n = 1). Sample size ranged from 4 to 105 participants. There were seven randomized controlled studies; however, no studies compared behavioural activation to an alternative psychological therapy. The effect sizes varied between small and large in the studies where effect size could be calculated (d = 0.24-1.7). Methodological quality of the included studies was variable. Intervention components were identifying and engaging in pleasurable activities, psychoeducation, and problem-solving. Adaptations included delivering sessions via telephone, delivering interventions via primary caregivers, and giving psychoeducation to caregivers.

CONCLUSION

The effectiveness of behavioural activation in randomized controlled trials varied from small to large (d = 0.24-1.7) in reducing depression. The content of behavioural activation was comparable to established treatment manuals. Adaptations appeared to support individuals to engage in therapy.

REVIEW REGISTRATION

PROSPERO 2018, CRD42018102604.

Comparison of Long-term Survival of Patients With Early-Stage Non-Small Cell Lung Cancer After Surgery vs Stereotactic Body Radiotherapy

IMPORTANCE

Previous comparisons of surgery and stereotactic body radiotherapy (SBRT) for early-stage (ES) non-small cell lung cancer (NSCLC) did not account for the extent of regional lymph node examination (LNE) during surgery.

OBJECTIVE

To compare long-term overall survival (OS) of patients with ES NSCLC after surgery vs SBRT when the extent of regional LNE in patients undergoing surgery is thoroughly considered.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study with survival comparisons using the multivariable Cox proportional hazards model and after propensity score matching. Data from the National Cancer Database were analyzed from October 28, 2018, through April 18, 2019. Patients with ES NSCLC diagnosed between January 1, 2004, and December 31, 2015, who underwent any curative-intent surgery or SBRT were included.

MAIN OUTCOMES AND MEASURES

Long-term OS.

RESULTS

Of 104 709 total patients, 91 330 underwent surgery (42 508 [46.5%] male; median [interquartile range] age, 68 [61-75] years) and 13 379 received SBRT (6065 [45.3%] male; median [interquartile range] age, 75 [68-81] years). Surgery, especially lobectomy (hazard ratio [HR], 0.53; 95% CI, 0.50-0.56), and regional LNE, especially when more than 10 lymph nodes were examined (HR, 0.73; 95% CI, 0.69-0.77), were associated with better long-term OS (P < .001). Pneumonectomy was not associated with reduced mortality risk when 0 nodes were examined (HR for stage T1, 1.43; 95% CI, 0.67-3.06; P = .35; HR for stage T2-T3, 0.62; 95% CI, 0.34-1.13; P = .12) or when more than 15 nodes were examined for stage T1 disease in patients younger than 80 years (HR, 0.77; 95% CI, 0.54-1.09; P = .14) or when patients aged 80 years or older received regional LNE of any extent (>15 nodes examined: HR for stage T1, 0.65; 95% CI, 0.16-2.64; P = .54; HR for stage T2-T3, 0.90; 95% CI, 0.50-1.60; P = .71). Less extensive surgery was not associated with improved OS when 0 nodes were examined in patients aged 80 years or older with stage T2 to T3 tumors (HR for lobectomy, 0.90; 95% CI, 0.65-1.25; P = .53) and in selected operable patients older than 75 years with stage T1 tumors (HR for lobectomy, 1.07; 95% CI, 0.57-2.00; P = .84).

CONCLUSIONS AND RELEVANCE

This study found that, overall, surgery coupled with regional LNE of appropriate extent was associated with the best long-term OS in patients with ES NSCLC.

Tyrosine kinase inhibitor interruptions, discontinuations and switching in patients with chronic-phase chronic myeloid leukemia in routine clinical practice: SIMPLICITY

SIMPLICITY (NCT01244750) is an observational study exploring tyrosine kinase inhibitor (TKI) use and management patterns in patients with chronic phase-chronic myeloid leukemia in the US and Europe in routine clinical practice. Herein we describe interruptions, discontinuations and switching of TKI therapy during the initial 2 years of treatment among 1121 patients prospectively enrolled between October 1, 2010 and March 7, 2017. Patient characteristics were broadly similar between the imatinib (n = 370), dasatinib (n = 376), and nilotinib (n = 375) cohorts. Treatment interruptions occurred in 16.4% (year 1) and 4.0% (year 2) of patients, mainly attributed to hematologic intolerances. Treatment discontinuations occurred in 21.8% (year 1) and 10.2% (year 2) of patients, with the highest rate within the first 3 months for intolerance. Switching of TKI was seen in 17.8% (year 1) and 9.5% (year 2) of patients. Significant associations were found between TKI switching and female gender (year 1), age ≥65 years at diagnosis (year 2) and treatment with imatinib (year 2). Intolerance was the most common reason given for patients discontinuing and for switching TKI therapy; however resistance was also cited. Lack of response monitoring in routine clinical practice may have resulted in lower identification of resistance in this dataset. Data from SIMPLICITY suggest that, in routine clinical practice, intolerance and resistance to TKIs influence decisions to change treatment. Changes in TKI therapy are frequent, with nearly a third of patients discontinuing their first-line TKI.

Comparative effectiveness clinical trials to advance treatment of myasthenia gravis

Myasthenia gravis (MG) presents many challenges for establishing treatment efficacy through clinical trials. Among these are the rarity and heterogeneity of the disease, spontaneous fluctuations, prolonged latency to effect for many immunosuppressive drugs, and the uncertain generalizability of results from randomized controlled trials (RCTs). Prospective observational study designs may overcome some of these limitations, but attention is required to ensure that internal validity is not compromised. Observational comparative effectiveness research (CER) utilizes data obtained during routine clinical care to evaluate the effectiveness of interventions in real-life practice conditions, thereby improving generalizability to the clinic. Compared with RCTs, observational CER studies may be less resource intensive and costly. Recent advances that have improved the feasibility of CER studies for MG are (1) the development of MG common data elements, (2) the publication of international consensus guidance for MG treatment, and (3) the development of a web-based REDCap database that can be shared and adapted to standardize data collection. This infrastructure could be used for multisite comparisons of commonly used therapies and provides longitudinal information on patient- and clinician-centered MG outcome measures. A challenge is to design studies that address the potential limitations of observational trials, such as confounding and selection and information bias.

First-line treatment selection and early monitoring patterns in chronic phase-chronic myeloid leukemia in routine clinical practice: SIMPLICITY

Achieving successful outcomes in chronic phase-chronic myeloid leukemia (CP-CML) requires careful monitoring of cytogenetic/molecular responses (CyR/MR). SIMPLICITY (NCT01244750) is an observational study exploring tyrosine kinase inhibitor use and management patterns in patients with CP-CML receiving first-line imatinib (n = 416), dasatinib (n = 418) or nilotinib (n = 408) in the US and 6 European countries in routine clinical practice. Twelve-month follow-up data of 1242 prospective patients (enrolled October 01 2010-September 02 2015) are reported. 81% of patients had baseline comorbidities. Treatment selection was based on perceived efficacy over patient comorbidity profile. There was a predominance of imatinib-treated patients enrolled earlier in the study, with subsequent shift toward dasatinib- and nilotinib-treated patients by 2013/2014. Monitoring for either CyR/MR improved over time and was documented for 36%, 82%, and 95% of patients by 3, 6, and 12 months, respectively; 5% had no documentation of CyR/MR monitoring during the first year of therapy. Documentation of MR/CyR testing was higher in Europe than the US (P < .001) and at academic versus community practices (P = .001). Age <65 years, patients being followed at sites within Europe, those followed at academic centers and patients no longer on first-line therapy were more likely to be monitored by 12 months. SIMPLICITY demonstrates that the NCCN and ELN recommendations on response monitoring have not been consistently translated into routine clinical practice. In the absence of appropriate monitoring practices, clinical response to TKI therapy cannot be established, any needed changes to treatment strategy will thus not be implemented, and long-term patient outcomes are likely to be impacted.

A protocol for the development of the STROCSS guideline: Strengthening the Reporting of Cohort Studies in Surgery

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No guidelines currently exist to support authors reporting on surgical cohort studies.

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We hereby provide our protocol for the development of the STROCSS Guideline for surgical cohort studies.

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Dissemination to interested parties and journals will be encouraged to endorse the reporting guideline.

Introduction

Strengthening the reporting of observational studies in epidemiology (STROBE) coined in 2007, highlighted the importance of improving the quality of observational research by providing an item checklist in order to avoid inadequate reporting of research. However, currently there are no reporting guidelines specific to surgical cohort studies, which have an extremely important role within the surgical literature. The recent development of surgery specific guidelines has underscored how surgical and procedural interventions require additional detail for readers to have a complete, clear, transparent and reproducible understanding. The objective of this research is to conduct a Delphi consensus exercise to develop the STROCSS guideline (Strengthening the Reporting of Cohort Studies in Surgery).

Methods and analysis

Current guidelines for case series (PROCESS), Cohort Studies (STROBE) and randomised controlled trials (CONSORT) will be analysed to compile items to form baseline material for developing cohort guidelines in the Delphi consensus exercise. The Delphi questionnaire will be administered via Google Forms and conducted using standard Delphi Methodology. Surgeons and individuals with significant experience of reviewing cohort studies as well as those with experience in developing reporting guidelines will be invited to participate. In the first round, existing items from PROCESS and STROBE will be put forward and participants will be invited to augment them or contribute further items for consideration. The provisional guidelines will then be updated in successive rounds using the nine-point Likert scale as proposed by the Grading Recommendations, Assessment, Development, and Evaluations (GRADE) working group. This process will be used to agree Standard definitions for the outcomes.

Dissemination

The work will be published in a peer-reviewed journal and presented at national and international meetings. Findings will be disseminated to interested parties, and journals will be encouraged to endorse the reporting guidelines.

Clinical assessments and care interventions to promote oral hydration amongst older patients: a narrative systematic review

BACKGROUND

Older patients in hospital may be unable to maintain hydration by drinking, leading to intravenous fluid replacement, complications and a longer length of stay. We undertook a systematic review to describe clinical assessment tools which identify patients at risk of insufficient oral fluid intake and the impact of simple interventions to promote drinking, in hospital and care home settings.

METHOD

MEDLINE, CINAHL, and EMBASE databases and two internet search engines (Google and Google Scholar) were examined. Articles were included when the main focus was use of a hydration/dehydration risk assessment in an adult population with/without a care intervention to promote oral hydration in hospitals or care homes. Reviews which used findings to develop new assessments were also included. Single case reports, laboratory results only, single technology assessments or non-oral fluid replacement in patients who were already dehydrated were excluded. Interventions where nutritional intake was the primary focus with a hydration component were also excluded. Identified articles were screened for relevance and quality before a narrative synthesis. No statistical analysis was planned.

RESULTS

From 3973 citations, 23 articles were included. Rather than prevention of poor oral intake, most focused upon identification of patients already in negative fluid balance using information from the history, patient inspection and urinalysis. Nine formal hydration assessments were identified, five of which had an accompanying intervention/ care protocol, and there were no RCT or large observational studies. Interventions to provide extra opportunities to drink such as prompts, preference elicitation and routine beverage carts appeared to support hydration maintenance, further research is required. Despite a lack of knowledge of fluid requirements and dehydration risk factors amongst staff, there was no strong evidence that increasing awareness alone would be beneficial for patients.

CONCLUSION

Despite descriptions of features associated with dehydration, there is insufficient evidence to recommend a specific clinical assessment which could identify older persons at risk of poor oral fluid intake; however there is evidence to support simple care interventions which promote drinking particularly for individuals with cognitive impairment.

TRIAL REGISTRATION

PROSPERO 2014:CRD42014015178.

Comparing the validity of the payment card and structured haggling willingness to pay methods: The case of a diabetes prevention program in rural Kenya

BACKGROUND

The objective of this study was to compare the theoretical validity of two willingness-to-pay (WTP) methods, the commonly used payment card (PC) and the recently developed structured haggling (SH), for estimating the potential benefits of a diabetes prevention program in rural Kenya.

METHODS

A convenience sample of adult residents from a rural county in Kenya (Kiambu), with no history of diabetes, was randomly assigned to one of two WTP methods, PC or SH, using structured face-to-face interviews from December 2011 to February 2012.

RESULTS

A total of 376 respondents completed the interviews using PC (n = 185) or SH (n = 191). More than 95% of respondents were willing to pay something for program access. The study showed that both methods were feasible in rural Kenya. SH resulted in a higher annual mean WTP than PC, Ksh504.05 (US$7.25) versus Ksh619.95 (US$5.90), respectively (p < 0.01). Based on theory, it was hypothesized that certain predisposing factors would result in greater WTP. Greater socio-economic status (measured using income proxies) resulted in greater unconditional WTP for both the PC and SH groups (t-tests and bivariate correlations) and conditional WTP (GLM models). GLM for PC showed being male, employed and having distant relatives with diabetes were significant predictors for WTP, while for SH being educated, employed and owning a vehicle were significant predictors.

CONCLUSION

Both PC and SH showed theoretical validity in rural Kenya. However, the use of SH over PC in rural Kenya may be the better choice given that SH more closely mirrors marketplace transactions in this setting and the use of SH resulted in more significant variables in the GLM models.

Redefining Amnestic Mild Cognitive Impairment as an Early Form of Alzheimer's Disease Based on Assessment of Memory Systems

BACKGROUND

It has been suggested that mild cognitive impairment (MCI) can be used to identify patients at risk of developing clinical stages of Alzheimer's disease (AD).

OBJECTIVE

The aim of this study was to describe the characteristics of amnesic syndrome of dementia of the Alzheimer's type (DAT) as a continuous degenerative process from normality to amnesic syndrome and provide a classification of the degrees of amnesia.

METHODS

Of 3,800 new incidental cases at the Memory Clinic, 747 were classified as non-demented patients. A 96-month follow-up study was conducted. We described and compared longitudinal outcomes from normality to amnesic syndrome based on immediate memory, verbal learning, free recall, and recognition using the memory scale from the Basic Neuropsychological Battery, version D (BNB-D) and created a new classification of memory impairment.

RESULTS

Based on differences observed in this longitudinal study, we classified patients in four memory stages: M1, Normal episodic memory; M2, mild impairment in learning and/or free recall; M3, clear impairment in learning and/or free recall; and M4, complete amnesic syndrome. With this new amnesia classification, we studied the chronological progression of all patients diagnosed without dementia from baseline to DAT conversion using the Kaplan-Meier estimator of survival probability (Log Rank/Mantel Cox comparison. χ2  = 171.84, p = 0.001).

CONCLUSION

This new classification of memory impairment can help increase the prediction certainty of conversion from amnestic MCI to AD and improve research on AD biomarkers and their relationship with memory as the principal manifestation of AD.

Epoch Analysis of On-Treatment Disability Progression Events over Time in the Tysabri Observational Program (TOP)

OBJECTIVE

To evaluate the effect of natalizumab on disability progression beyond 2 years of treatment in clinical practice.

METHODS

Analyses included the 496 relapsing-remitting multiple sclerosis (RRMS) patients among 5122 patients in the Tysabri Observational Program (TOP) who had completed 4 continuous years of natalizumab treatment and had baseline (study enrollment) and postbaseline Expanded Disability Status Scale (EDSS) assessments. Proportions of patients with 6-month or 12-month confirmed ≥1.0-point EDSS progression relative to baseline were compared in treatment months 1-24 and 25-48. Sensitivity analyses compared progression rates in months 13-24 and 25-36.

RESULTS

Baseline characteristics appeared similar between the overall TOP population (N = 5122), patients who had completed 4 years of natalizumab treatment (n = 469), and patients eligible to complete 4 years in TOP who had discontinued natalizumab after 2 years of treatment (n = 514). Among 4-year completers, the proportion of patients with 6-month and 12-month confirmed EDSS progression decreased between months 1-24 and 25-48 of natalizumab treatment by 42% (from 10.9% to 6.3%; p < 0.01) and 52% (from 9.5% to 4.6%; p < 0.01), respectively. Few patients had 6-month or 12-month confirmed EDSS progression in both epochs (0.6% and 0.2%, respectively). Between months 13-24 and 25-36 of treatment, the proportion of patients with 6-month and 12-month confirmed EDSS progression decreased by 60% (from 7.5% to 3.0%; p < 0.01) and 58% (from 6.7% to 2.8%; p < 0.01), respectively. Significant reductions in disability progression events between months 13-24 and 25-36 were also observed in relapse-free patients.

CONCLUSION

In this observational study, the disability progression rate decreased further beyond 2 years of natalizumab treatment. Patients who responded well and remained on continuous natalizumab therapy for over 4 years had sustained and potentially enhanced reductions in EDSS progression over time.

Chronic rhinosinusitis identification in administrative databases and health surveys: A systematic review

OBJECTIVES/HYPOTHESIS

Much of the epidemiological data on chronic rhinosinusitis (CRS) are based on large administrative databases and health surveys. The accuracy of CRS identification with these methods is unknown.

METHODS

A systematic review was performed to identify studies that measured the accuracy of CRS diagnoses in large administrative databases or within health surveys. The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess study quality.

RESULTS

Of 512 abstracts initially identified, 122 were selected for full-text review; only three studies (2.5%) measured the accuracy of CRS patient identification. In a single, large administrative database study with a CRS prevalence of 54.8%, a single International Classification of Diseases-9th Revision diagnostic code for CRS had a positive predictive value (PPV) of only 34%. A diagnostic code algorithm identified CRS patients with a PPV of 91.3% (95% confidence interval [CI], 85.3-95.1); in a population with a CRS prevalence of 5%, this algorithm had a PPV of 31%. In health survey studies having an estimated CRS prevalence of 25% to 46%, self-reported symptom-based CRS diagnosis had a PPV of 62% (95% CI, 50.2-72.1) when nasal endoscopy was the gold standard for CRS diagnosis, and 70% (95% CI, 57.4-80.8) when otolaryngologist-based CRS diagnosis (after interview and nasal endoscopy) was the gold standard.

CONCLUSION

Most health administrative data and health surveys examining CRS did not consider the accuracy of case identification. For unselected populations, administrative data and health surveys using self-reported diagnoses inaccurately identify patients with CRS. Epidemiological results based on such data should be interpreted with these results in mind. Laryngoscope, 126:1303-1310, 2016.

Management of diverticular disease

Diverticular disease is a common condition in Western countries and the incidence and prevalence of the disease is increasing. The pathogenetic factors involved include structural changes in the gut that increase with age, a diet low in fibre and rich in meat, changes in intestinal motility, the concept of enteric neuropathy and an underlying genetic background. Current treatment strategies are hampered by insufficient options to stratify patients according to individual risk. One of the main reasons is the lack of an all-encompassing classification system of diverticular disease. In response, the German Society for Gastroenterology and Digestive Diseases (DGVS) has proposed a classification system as part of its new guideline for the diagnosis and management of diverticular disease. The classification system includes five main types of disease: asymptomatic diverticulosis, acute uncomplicated and complicated diverticulitis, as well as chronic diverticular disease and diverticular bleeding. Here, we review prevention and treatment strategies stratified by these five main types of disease, from prevention of the first attack of diverticulitis to the management of chronic complications and diverticular bleeding.

Treatment of Hypertensive Patients with a Fixed-Dose Combination of Bisoprolol and Amlodipine: Results of a Cohort study with More Than 10,000 Patients

Introduction

Many patients need more than one antihypertensive agent for effective blood pressure (BP) control. Prescription of a fixed-dose combination (FDC) of bisoprolol and amlodipine in one tablet has been shown to significantly improve patient adherence. This non-interventional study investigated the effects on adherence and BP control of switching from a free-dose combination of the two antihypertensive substances to a FDC in a larger patient population.

Methods

Patients aged ≥18 years with essential hypertension were switched at least 4 weeks prior to study initiation from a free-dose combination of bisoprolol and amlodipine to the FDC. Dosage adjustment was implemented only if medically indicated. Adherence was assessed on the basis of the ratio of pills used to pills dispensed (%) at each visit (pill count). BP and key laboratory values were determined at baseline, 3 and 6 months.

Results

10,532 patients (average age 59 years; 48% female) were recruited between 2013 and 2014; 22% of patients had type 2 diabetes and 38% had cardiovascular disease. The mean doses of the freely combined drugs prior to switching were 5.5 mg bisoprolol and 6.1 mg amlodipine once daily. The mean daily doses prescribed in the FDC were 5.8 and 6.4 mg, respectively. Pill counts at 6 months revealed a good to excellent adherence in >95% of the patients. Comparison of BP at baseline and at 6 months showed substantial changes (mean systolic BP: 147.3 vs. 130.9 mmHg; mean diastolic BP: 87.9 vs. 79.1 mmHg). Clinically relevant improvement in systolic BP was established for 82% of patients. In patients with comorbidities, switching to FDC produced a substantial improvement in BP. A total of 89 (0.7%) adverse events (AEs) were reported, including edema, headache, dizziness, bradycardia, nausea, and skin reactions. Only three AEs were classified as serious.

Conclusion

These data from a non-interventional study in a large patient population demonstrate the benefits of prescribing a FDC of bisoprolol–amlodipine in terms of an excellent adherence and an associated improvement in control of previously elevated BP, which may be relevant in real-life practice.

Funding

Merck KGaA.

Electronic supplementary material

The online version of this article (doi:10.1007/s40119-015-0045-z) contains supplementary material, which is available to authorized users.

Searching for randomized controlled trials and systematic reviews on exercise. A descriptive study

CONTEXT AND OBJECTIVE

The current paradigm of science is to accumulate as much research data as possible, with less thought given to navigation or synthesis of the resulting mass, which hampers locating and using the research. The aim here was to describe the number of randomized controlled trials (RCTs) and systematic reviews (SRs) focusing on exercise, and their journal sources, that have been indexed in PubMed over time.

DESIGN AND SETTING

Descriptive study conducted at Bond University, Australia.

METHOD

To find RCTs, a search was conducted in PubMed Clinical Queries, using the category "Therapy" and the Medical Subject Headings (MeSH) term "Exercise". To find SRs, a search was conducted in PubMed Clinical Queries, using the category "Therapy", the MeSH term "Exercise" and various methodological filters.

RESULTS

Up until 2011, 9,354 RCTs about exercise were published in 1,250 journals and 1,262 SRs in 513 journals. Journals in the area of Sports Science published the greatest number of RCTs and journals categorized as belonging to "Other health professions" area (for example nursing or psychology) published the greatest number of SRs. The Cochrane Database of Systematic Reviews was the principal source for SRs, with 9.8% of the total, while the Journal of Strength and Conditioning Research and Medicine & Science in Sports & Exercise published 4.4% and 5.0% of the RCTs, respectively.

CONCLUSIONS

The rapid growth and resulting scatter of RCTs and SRs on exercise presents challenges for locating and using this research. Solutions for this issue need to be considered.

Does the average drug exposure in pregnant women affect pregnancy outcome? A comparison of two approaches to estimate the baseline risks of adverse pregnancy outcome

PURPOSE

The results of observational cohort studies on drug effects on pregnancy outcome may depend among others on suitable comparison cohorts. The aim of this investigation was to compare two distinct definitions of maternal exposure status for comparison cohorts.

METHODS

We performed an observational cohort study of prospectively ascertained pregnant women who spontaneously contacted the Teratology Information Service (TIS) Berlin for drug risk consultation. The only exclusion criteria were exposures to established teratogens and/or fetotoxicants. Pregnancy outcomes of 3250 women with this "average drug exposure" were compared with 546 non-exposed or insignificantly exposed pregnancies.

RESULTS

Neither the rate of major birth defects (3.0%; aOR 1.62; 95% CI 0.8-3.3) nor the risk of spontaneous abortion (16.0%; aHR 1.20; 95% CI 0.8-1.7) was significantly increased after average drug exposure, whereas the rate of electively terminated pregnancies was higher (11.1%; aHR 2.05; 95% CI 1.2-3.4). There were no differences in the risk of preterm birth (9.9%; aOR 1.38; 95% CI 0.9-2.0) and infants' birth weight (p = 0.60).

CONCLUSIONS

This study does not provide evidence for an increased risk of adverse pregnancy outcome after average drug exposure during pregnancy. Therefore, comparison cohorts with average drug exposure are appropriate for studies on potential teratogens or fetotoxicants based on observational data collected by TIS.

The role of observational studies in optimizing the clinical management of chronic myeloid leukemia

Survival has increased dramatically for patients with chronic phase chronic myeloid leukemia (CP-CML) using BCR-ABL targeted tyrosine kinase inhibitors, such that life expectancy is expected to approximate that of patients without CP-CML. Randomized controlled trials (RCTs) and observational studies provide valuable insights into the management of chronic diseases such as CP-CML. RCTs are undoubtedly the backbone of clinical research, and the 'gold standard' for evaluating the efficacy and safety of new therapies. However, many questions surrounding the optimal management of patients with CML remain unanswered, and it is widely accepted that these questions will be best answered by evaluating the use of available therapies in clinical practice. Observational studies can extend the knowledge base beyond the clinical trial setting and thus capture a more accurate picture of everyday clinical practice, particularly patients' experiences of long-term CML treatment. There is therefore growing interest in and appreciation of the value of observational research. This review article will examine the relative merits of RCTs and observational studies in the setting of CML, highlighting those factors - such as the advancing age of the CML patient population and growing importance of patient-reported outcomes - that mean that observational studies should play an important role in shaping clinical practice. This article also provides an overview of what observational studies have told us thus far about the optimal management of patients with CML, outlines some of the key remaining unanswered clinical questions in CML, and summarizes ongoing observational studies designed to provide answers to these key questions.

Is Participation in Certain Sports Associated With Knee Osteoarthritis? A Systematic Review

OBJECTIVE

  Information regarding the relative risks of developing knee osteoarthritis (OA) as a result of sport participation is critical for shaping public health messages and for informing knee-OA prevention strategies. The purpose of this systematic review was to investigate the association between participation in specific sports and knee OA.

DATA SOURCES

  We completed a systematic literature search in September 2012 using 6 bibliographic databases (PubMed; Ovid MEDLINE; Journals@Ovid; American College of Physicians Journal Club; Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Review, Database of Abstracts of Reviews of Effects; and Ovid HealthStar), manual searches (4 journals), and reference lists (56 articles).

STUDY SELECTION

  Studies were included if they met the following 4 criteria: (1) an aim was to investigate an association between sport participation and knee OA; (2) the outcome measure was radiographic knee OA, clinical knee OA, total knee replacement, self-reported diagnosis of knee OA, or placement on a waiting list for a total knee replacement; (3) the study design was case control or cohort; and (4) the study was written in English. Articles were excluded if the study population had an underlying condition other than knee OA.

DATA EXTRACTION

  One investigator extracted data (eg, group descriptions, knee OA prevalence, source of nonexposed controls).

DATA SYNTHESIS

  The overall knee-OA prevalence in sport participants (n = 3759) was 7.7%, compared with 7.3% among nonexposed controls (referent group n = 4730, odds ratio [OR] = 1.1). Specific sports with a significantly higher prevalence of knee OA were soccer (OR = 3.5), elite-level long-distance running (OR = 3.3), competitive weight lifting (OR = 6.9), and wrestling (OR = 3.8). Elite-sport (soccer or orienteering) and nonelite-sport (soccer or American football) participants without a history of knee injury had a greater prevalence of knee OA than nonexposed participants.

CONCLUSIONS

  Participants in soccer (elite and nonelite), elite-level long-distance running, competitive weight lifting, and wrestling had an increased prevalence of knee OA and should be targeted for risk-reduction strategies.

The quality of control groups in nonrandomized studies published in the Journal of Hand Surgery

PURPOSE

To evaluate control group selection in nonrandomized studies published in the Journal of Hand Surgery American (JHS).

METHODS

We reviewed all papers published in JHS in 2013 to identify studies that used nonrandomized control groups. Data collected included type of study design and control group characteristics. We then appraised studies to determine whether authors discussed confounding and selection bias and how they controlled for confounding.

RESULTS

Thirty-seven nonrandomized studies were published in JHS in 2013. The source of control was either the same institution as the study group, a different institution, a database, or not provided in the manuscript. Twenty-nine (78%) studies statistically compared key characteristics between control and study group. Confounding was controlled with matching, exclusion criteria, or regression analysis. Twenty-two (59%) papers explicitly discussed the threat of confounding and 18 (49%) identified sources of selection bias.

CONCLUSIONS

In our review of nonrandomized studies published in JHS, papers had well-defined controls that were similar to the study group, allowing for reasonable comparisons. However, we identified substantial confounding and bias that were not addressed as explicit limitations, which might lead the reader to overestimate the scientific validity of the data.

CLINICAL RELEVANCE

Incorporating a brief discussion of control group selection in scientific manuscripts should help readers interpret the study more appropriately. Authors, reviewers, and editors should strive to address this component of clinical importance.

Effectiveness of angiotensin II receptor antagonists in a cohort of Dutch patients with type 2 diabetes mellitus (ZODIAC-14)

OBJECTIVE

There is limited evidence with respect to the between-group effects of various angiotensin receptor blockers (ARBs) on blood pressure and albuminuria in patients with type 2 diabetes mellitus. Therefore, we aimed to investigate the effects of differing ARBs on systolic blood pressure (SBP) and the albumin-creatinine ratio after 1 year in a large cohort of patients with type 2 diabetes mellitus.

METHODS

In 2007, 24 940 primary care patients with type 2 diabetes mellitus participated in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) study, a prospective observational cohort study. Patients were included in the current study if they were prescribed an ARB in 2007 and if 1-year follow-up data were available. The final study population comprised 3610 patients. Multivariate mixed-model analyses were performed to estimate effects of the various ARBs on SBP and albuminuria. Stratified subgroup analyses were performed according to baseline hypertension and albuminuria.

RESULTS

SBP decreased in all groups, the largest decrease being observed in the group receiving telmisartan. No significant or relevant changes over time were observed among groups for SBP and albuminuria. In the subgroup (n=1225) of normotensive patients, telmisartan was associated with a larger decrease in SBP after 1 year compared to other ARBs, without different effects on the albumin-creatinine ratio.

CONCLUSIONS

We observed no differences in effects on SBP and the albumin-creatinine ratio among differing ARBs in patients with type 2 diabetes mellitus.

Effects of HIV antiretroviral therapy on sexual and injecting risk-taking behavior: a systematic review and meta-analysis

BACKGROUND

Increased global access and use of antiretroviral therapy (ART) for human immunodeficiency virus (HIV) has been postulated to undermine HIV prevention efforts by changing individual risk-taking behavior. This review aims to determine whether ART use is associated with changes in sexual or injecting risk-taking behavior or diagnosis of sexually transmitted infections (STIs).

METHODS

A systematic review and meta-analysis was conducted of HIV-seropositive participants receiving ART compared with no ART use in experimental or observational studies. Primary outcomes included (1) any unprotected sexual intercourse, (2) STI diagnoses, and (3) any unsafe injecting behavior.

RESULTS

Fifty-eight studies met the selection criteria. Fifty-six studies containing 32 857 participants reported unprotected sex; 11 studies containing 16 138 participants reported STI diagnoses; and 4 studies containing 1600 participants reported unsafe injecting behavior. All included studies were observational. Unprotected sex was lower in participants receiving ART than in those not receiving ART (odds ratio [OR], 0.73; 95% confidence interval [CI], .64-.83; P < .001; heterogeneity I(2) = 79%) in both high-income (n = 38) and low-/middle-income country (n = 18) settings, without any evidence of publication bias. STI diagnoses were also lower among individuals on ART (OR, 0.58; 95% CI, .33-1.01; P = .053; I(2) = 92%); however, there was no difference in injecting risk-taking behavior with antiretroviral use (OR, 0.90; 95% CI, .60-1.35; P = .6; I(2) = 0%).

CONCLUSIONS

Despite concerns that use of ART might increase sexual or injecting risk-taking, available research suggests that unprotected sex is reduced among HIV-infected individuals on treatment. The reasons for this are not yet clear, although self-selection and mutually reinforcing effects of HIV treatment and prevention messages among people on ART are likely.

Bipolar or borderline: a clinical overview

OBJECTIVE

To examine the empirical literature on diagnostic validators in borderline personality and bipolar illness.

METHOD

Using principles of evidence-based medicine, the highest levels of evidence were emphasized in interpretation of similarities or differences between bipolar illness and borderline personality on the five standard diagnostic validators in psychiatric nosology: symptoms, course, genetics, treatment response, and neurobiology.

RESULTS

Bipolar illness and borderline personality were found to be similar in the nosological validator of symptoms of mood lability and impulsivity, but differed notably on all other diagnostic validators, especially the course validator of past sexual abuse and the genetic validator of a bipolar family history. They also differ notably in the symptom validator of parasuicidal self-harm. Treatment response and neurobiological differences were also present and consistent.

CONCLUSION

This review of the literature indicates that these two conditions, bipolar illness and borderline personality, are different and can be distinguished. The much stronger biological and genetic evidence for bipolar illness in particular suggests that the two conditions can be reasonably seen as different kinds of clinical entities, namely a biological disease versus a psychosocially caused clinical picture. If this interpretation is correct, similarities between the two conditions, such as mood lability and impulsivity, are superficial, while differences are profound. Further, true comorbidity may be much less common than often presumed.

Policy expectations and reality of telemedicine - a critical analysis of health care outcomes, costs and acceptance for congestive heart failure

A critical review of evidence was carried out to discover whether the actual performance of telemedicine fulfils the expectations of German policy-makers. The analysis was conducted using the example of telemedicine for congestive heart failure (CHF). It was based on both German and international evidence. The PubMed, MEDLINE, Google Scholar and Cochrane Library databases were searched, as well as public sources from the German Federal Ministry of Health. Forty-five studies reporting patient outcomes, costs or acceptance of telemedicine for CHF were included in the review, of which 28 were interventional. The policy expectations of telemedicine generally are: high technology acceptance and improved patient outcomes at lower costs. However, in the field of CHF, policy-makers underestimate the complexity of telemedicine and the technology has not yet lived up to its expectations. Although some studies show improvements in all-cause mortality and CHF-related hospitalisations, there is excessive study heterogeneity and vagueness in the areas of costs and acceptance. Methodological insufficiencies as well as the scarcity of evidence in the German context do not allow definite conclusions to be drawn. Policy-makers and other stakeholders should increase their efforts to consolidate isolated telemedicine projects, establish guidelines for clinical treatment procedures and economic evaluations, and define industry/technical device standards to enhance the comparability of interventions. Imposing the use of telemedicine on patients and physicians is not likely to be fruitful. A successful adaptation requires an analysis of needs and continuous education on both sides.

Longterm follow-up in European respiratory health studies - patterns and implications

Background

Selection bias is a systematic error in epidemiologic studies that may seriously distort true measures of associations between exposure and disease. Observational studies are highly susceptible to selection bias, and researchers should therefore always examine to what extent selection bias may be present in their material and what characterizes the bias in their material. In the present study we examined long-term participation and consequences of loss to follow-up in the studies Respiratory Health in Northern Europe (RHINE), Italian centers of European Community Respiratory Health Survey (I-ECRHS), and the Italian Study on Asthma in Young Adults (ISAYA).

Methods

Logistic regression identified predictors for follow-up participation. Baseline prevalence of 9 respiratory symptoms (asthma attack, asthma medication, combined variable with asthma attack and/or asthma medication, wheeze, rhinitis, wheeze with dyspnea, wheeze without cold, waking with chest tightness, waking with dyspnea) and 9 exposure-outcome associations (predictors sex, age and smoking; outcomes wheeze, asthma and rhinitis) were compared between all baseline participants and long-term participants. Bias was measured as ratios of relative frequencies and ratios of odds ratios (ROR).

Results

Follow-up response rates after 10 years were 75% in RHINE, 64% in I-ECRHS and 53% in ISAYA. After 20 years of follow-up, response was 53% in RHINE and 49% in I-ECRHS. Female sex predicted long-term participation (in RHINE OR (95% CI) 1.30(1.22, 1.38); in I-ECRHS 1.29 (1.11, 1.50); and in ISAYA 1.42 (1.25, 1.61)), as did increasing age. Baseline prevalence of respiratory symptoms were lower among long-term participants (relative deviations compared to total baseline population 0-15% (RHINE), 0-48% (I-ECRHS), 3-20% (ISAYA)), except rhinitis which had a slightly higher prevalence. Most exposure-outcome associations did not differ between long-term participants and all baseline participants, except lower OR for rhinitis among ISAYA long-term participating smokers (relative deviation 17% (smokers) and 44% (10–20 pack years)).

Conclusions

We found comparable patterns of long-term participation and loss to follow-up in RHINE, I-ECRHS and ISAYA. Baseline prevalence estimates for long-term participants were slightly lower than for the total baseline population, while exposure-outcome associations were mainly unchanged by loss to follow-up.

Is increased joint loading detrimental to obese patients with knee osteoarthritis? A secondary data analysis from a randomized trial

OBJECTIVE

To investigate whether increased knee joint loading due to improved ambulatory function and walking speed following weight loss achieved over 16 weeks accelerates symptomatic and structural disease progression over a subsequent 1 year weight maintenance period in an obese population with knee osteoarthritis (OA).

METHODS

Data from a prospective study of weight loss in obese patients with knee OA (the CARtilage in obese knee OsteoarThritis (CAROT) study) were used to determine changes in knee joint compressive loadings (model estimated) during walking after a successful 16 week weight loss intervention. The participants were divided into 'Unloaders' (participants that reduced joint loads) and 'Loaders' (participants that increased joint loads). The primary symptomatic outcome was changes in knee symptoms, measured with the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, during a subsequent 52 weeks weight maintenance period. The primary structural outcome was changes in tibiofemoral cartilage loss assessed semi-quantitatively (Boston Leeds Knee Osteoarthritis Score (BLOKS) from MRI after the 52 weight maintenance period.

RESULTS

157 participants (82% of the CAROT cohort) with medial and/or lateral knee OA were classified as Unloaders (n = 100) or Loaders (n = 57). The groups showed similar significant changes in symptoms (group difference: -2.4 KOOS points [95% CI -6.8:1.9]) and cartilage loss (group difference: -0.06 BLOKS points [95% CI -0.22:0.11) after 1 year, with no statistically significant differences between Loaders and Unloaders.

CONCLUSION

For obese patients undergoing a significant weight loss, increased knee joint loading for 1 year was not associated with accelerated symptomatic and structural disease progression compared to a similar weight loss group that had reduced ambulatory compressive knee joint loads.

CLINICALTRIALSGOV

NCT00655941.

An Analysis of Methodologies That Can Be Used to Validate if a Perioperative Surgical Home Improves the Patient-centeredness, Evidence-based Practice, Quality, Safety, and Value of Patient Care

Approximately 80 million inpatient and outpatient surgeries are performed annually in the United States. Widely variable and fragmented perioperative care exposes these surgical patients to lapses in expected standard of care, increases the chance for operational mistakes and accidents, results in unnecessary and potentially detrimental care, needlessly drives up costs, and adversely affects the patient healthcare experience. The American Society of Anesthesiologists and other stakeholders have proposed a more comprehensive model of perioperative care, the Perioperative Surgical Home (PSH), to improve current care of surgical patients and to meet the future demands of increased volume, quality standards, and patient-centered care. To justify implementation of this new healthcare delivery model to surgical colleagues, administrators, and patients and maintain the integrity of evidenced-based practice, the nascent PSH model must be rigorously evaluated. This special article proposes comparative effectiveness research aims or objectives and an optimal study design for the novel PSH model.

The role of oxidized low-density lipoproteins in atherosclerosis: the myths and the facts

The oxidative modification hypothesis of atherosclerosis, which assigns to oxidized low-density lipoproteins (LDLs) a crucial role in atherosclerosis initiation and progression, is still debated. This review examines the role played by oxidized LDLs in atherogenesis taking into account data derived by studies based on molecular and clinical approaches. Experimental data carried out in cellular lines and animal models of atherosclerosis support the proatherogenic role of oxidized LDLs: (a) through chemotactic and proliferating actions on monocytes/macrophages, inciting their transformation into foam cells; (b) through stimulation of smooth muscle cells (SMCs) recruitment and proliferation in the tunica intima; (c) through eliciting endothelial cells, SMCs, and macrophages apoptosis with ensuing necrotic core development. Moreover, most of the experimental data on atherosclerosis-prone animals benefiting from antioxidant treatment points towards a link between oxidative stress and atherosclerosis. The evidence coming from cohort studies demonstrating an association between oxidized LDLs and cardiovascular events, notwithstanding some discrepancies, seems to point towards a role of oxidized LDLs in atherosclerotic plaque development and destabilization. Finally, the results of randomized clinical trials employing antioxidants completed up to date, despite demonstrating no benefits in healthy populations, suggest a benefit in high-risk patients. In conclusion, available data seem to validate the oxidative modification hypothesis of atherosclerosis, although additional proofs are still needed.

A systematic review of the activity and impact of emergency care practitioners in the NHS

BACKGROUND

The NHS has seen a great expansion in the number of emergency care practitioners (ECPs) working in prehospital, primary and acute care settings since the role was introduced in 2003. This paper updates and expands on two previous reviews of ECP roles by identifying and discussing all empirical studies to date that examined the impact of ECP services in the NHS.

OBJECTIVES

To summarise the national evidence-based literature on the impact of ECPs on healthcare delivery, effectiveness of practice and related health service resource use.

METHODS

Searches in MEDLINE, EMBASE and CINAHL databases, and two internet search engines (Google and Google Scholar). Identified publications were screened for relevance and quality before a description and synthesis of their findings. No statistical comparison was undertaken.

RESULTS

Studies from the peer-reviewed literature (n=15) and project reports (n=6) were included. Overall, there was evidence that investment in ECP roles is beneficial for the quality of care reported by patients and cost efficiency savings. There was clear support from staff and patients for ECP services, and a number of studies of high methodological quality described care processes (diagnosis, investigations instigated and treatment initiated) provided by ECPs to be equivalent to or better to that provided by practitioners with traditional roles. Prehospital ECPs provided 'added value' by treating more patients at the scene thereby reducing unnecessary referral to emergency departments. It was often unclear whether the ECP intervention was part of a larger service change and/or new investment.

CONCLUSIONS

Successful implementation of the ECP role has been described. Further evaluations should consider whether the beneficial impact of the role transfers equally across all operational settings and patient groups, and is not just a reflection of new investment in clinical services.

Establishing the Melbourne Injecting Drug User Cohort Study (MIX): rationale, methods, and baseline and twelve-month follow-up results

BACKGROUND

Cohort studies provide an excellent opportunity to monitor changes in behaviour and disease transmission over time. In Australia, cohort studies of people who inject drugs (PWID) have generally focused on older, in-treatment injectors, with only limited outcome measure data collected. In this study we specifically sought to recruit a sample of younger, largely out-of-treatment PWID, in order to study the trajectories of their drug use over time.

METHODS

Respondent driven sampling, traditional snowball sampling and street outreach methods were used to recruit heroin and amphetamine injectors from one outer-urban and two inner-urban regions of Melbourne, Australia. Information was collected on participants' demographic and social characteristics, drug use characteristics, drug market access patterns, health and social functioning, and health service utilisation. Participants are followed-up on an annual basis.

RESULTS

688 PWID were recruited into the study. At baseline, the median age of participants was 27.6 years (IQR: 24.4 years - 29.6 years) and two-thirds (67%) were male. Participants reported injecting for a median of 10.2 years (range: 1.5 months - 21.2 years), with 11% having injected for three years or less. Limited education, unemployment and previous incarceration were common. The majority of participants (82%) reported recent heroin injection, and one third reported being enrolled in Opioid Substitution Therapy (OST) at recruitment. At 12 months follow-up 458 participants (71% of eligible participants) were retained in the study. There were few differences in demographic and drug-use characteristics of those lost to follow-up compared with those retained in the study, with attrition significantly associated with recruitment at an inner-urban location, male gender, and providing incomplete contact information at baseline.

CONCLUSIONS

Our efforts to recruit a sample of largely out-of-treatment PWID were limited by drug market characteristics at the time, where fluctuating heroin availability has led to large numbers of PWID accessing low-threshold OST. Nevertheless, this study of Australian injectors will provide valuable data on the natural history of drug use, along with risk and protective factors for adverse health outcomes associated with injecting drug use. Comprehensive follow-up procedures have led to good participant retention and limited attrition bias.

Statistical principles for prospective study protocols:: design, analysis, and reporting

In the design of scientific studies it is essential to decide on which scientific questions one aims to answer, just as it is important to decide on the correct statistical methods to use to answer these questions. The correct use of statistical methods is crucial in all aspects of research to quantify relationships in data. Despite an increased focus on statistical content and complexity of biomedical research these topics remain difficult for most researchers. Statistical methods enable researchers to condense large spreadsheets with data into means, proportions, and difference between means, risk differences, and other quantities that convey information. One of the goals in biomedical research is to develop parsimonious models - meaning as simple as possible. This approach is valid if the subsequent research report (the article) is written independent of whether the results are "statistically significant" or not. In the present paper we outline the considerations and suggestions on how to build a trial protocol, with an emphasis on having a rigorous protocol stage, always leading to a full article manuscript, independent of statistical findings. We conclude that authors, who find (rigorous) protocol writing too troublesome, will realize that they have already written the first half of the final paper if they follow these recommendations; authors simply need to change the protocols future tense into past tense. Thus, the aim of this clinical commentary is to describe and explain the statistical principles for trial protocols in terms of design, analysis, and reporting of findings.

Confounding and effect modification in studies of diet and childhood asthma and allergies

OBJECTIVE

To propose a comprehensive set of confounders and effect modifiers that should be considered in epidemiologic investigations.

METHODS

Two reviewers independently critiqued studies included in a recent systematic review and extracted data on the confounders and effect modifiers that were considered and the approaches used to justify inclusion.

RESULTS

Of the 62 studies reviewed, 20 were cohort, 16 case-control, 25 cross-sectional studies, and one ecologic study. All cohort, cross-sectional, and ecologic studies had some adjustment for confounding or consideration of effect modification, but this was only the case for 7/16 (44%) case-control studies. Of the 53 studies that considered confounding or effect modification, 39/53 (74%) gave no justification for the inclusion of the variables considered. Studies that justified the inclusion of the variables did so based on empirical evidence (n = 10), conceptual justification (n = 7), or a combination of the two (n = 3). Confounding was handled mainly by using regression modeling, but some case-control studies utilized matching and anova. Ten studies handled effect modification by stratification, eight tested for interaction, and five used both strategies.

CONCLUSIONS

We have found substantial shortcomings in the handling of confounding and effect modification in studies of diet and development of childhood asthma/allergies. Selection of variables should be based on conceptual considerations and empirical evidence. Using this approach, we have proposed a comprehensive set of confounders and effect modifiers that need to be considered in future studies.