Forest plots: trying to see the wood and the trees

Sources of Safety Data and Statistical Strategies for Design and Analysis: Clinical Trials

BACKGROUND

There has been an increased emphasis on the proactive and comprehensive evaluation of safety endpoints to ensure patient well-being throughout the medical product life cycle. In fact, depending on the severity of the underlying disease, it is important to plan for a comprehensive safety evaluation at the start of any development program. Statisticians should be intimately involved in this process and contribute their expertise to study design, safety data collection, analysis, reporting (including data visualization), and interpretation.

METHODS

In this manuscript, we review the challenges associated with the analysis of safety endpoints and describe the safety data that are available to influence the design and analysis of premarket clinical trials.

RESULTS

We share our recommendations for the statistical and graphical methodologies necessary to appropriately analyze, report, and interpret safety outcomes, and we discuss the advantages and disadvantages of safety data obtained from clinical trials compared to other sources.

CONCLUSIONS

Clinical trials are an important source of safety data that contribute to the totality of safety information available to generate evidence for regulators, sponsors, payers, physicians, and patients. This work is a result of the efforts of the American Statistical Association Biopharmaceutical Section Safety Working Group.

Low-level neural auditory discrimination dysfunctions in specific language impairment-A review on mismatch negativity findings

In specific language impairment (SLI), there is a delay in the child’s oral language skills when compared with nonverbal cognitive abilities. The problems typically relate to phonological and morphological processing and word learning. This article reviews studies which have used mismatch negativity (MMN) in investigating low-level neural auditory dysfunctions in this disorder. With MMN, it is possible to tap the accuracy of neural sound discrimination and sensory memory functions. These studies have found smaller response amplitudes and longer latencies for speech and non-speech sound changes in children with SLI than in typically developing children, suggesting impaired and slow auditory discrimination in SLI. Furthermore, they suggest shortened sensory memory duration and vulnerability of the sensory memory to masking effects. Importantly, some studies reported associations between MMN parameters and language test measures. In addition, it was found that language intervention can influence the abnormal MMN in children with SLI, enhancing its amplitude. These results suggest that the MMN can shed light on the neural basis of various auditory and memory impairments in SLI, which are likely to influence speech perception.

Comparison among fertility-sparing therapies for well differentiated early-stage endometrial carcinoma and complex atypical hyperplasia

OBJECTIVE

To compare fertility-sparing therapies including oral progestogens, hysteroscopic resection (HR), and the levonorgestrel- releasing intrauterine system (LNG-IUS) in achieving disease regression, recurrence and live birth rate in well differentiate early-stage endometrial carcinoma (eEC) and complex atypical hyperplasia(CAH).

STUDY DESIGN

This was a meta-analysis of previous studies focus on the fertility-sparing therapy for well differentiate early-stage endometrial carcinoma (eEC) and complex atypical hyperplasia (CAH).

DATE SOURCES

Medline, the Cochrane Library and Embase was searched with the terms and Synonyms: words similar to eEC and CAH with therapies associated with fertility-sparing.

MAIN OUTCOME MEASURES

The number of all patients accepted fertility sparing therapies, patients got regressed, relapsed and delivered were extracted from each study, and the regression, recurrence, and live birth rate of each study were calculated. The regression, recurrence and live birth rates between each two interventions were compared with the aid of meta-regression in packages of "meta" and "meta for" written in R.

RESULTS

Fifty-four studies reported fertility sparing therapies in young women with eEC and CAH were included. Meta-analysis showed that HR followed by progestogens achieved a higher pooled regression (98.06% vs 77.20% P < 0.0001) and live birth rate (52.57% vs 33.38%, P = 0.0944) and a lower recurrence rate compared with oral progestogens alone (4.79% vs 32.17% P = 0.0004). At the same time, the pooled live birth rate (52.57% vs 18.09% P =0.0399) of HR followed by progestogens are significantly higher than the LNG-IUS alone. Which no statistical difference in regression (98.06% vs 94.24%; P = 0.4098) and recurrence rates (4.79% vs 3.90% P = 0.8561) was seen.

CONCLUSIONS

Of the available fertility-sparing therapeutic options, HR followed by progestogens may be a more effective one.

Left ventricular contractile reserve by stress echocardiography as a predictor of response to cardiac resynchronization therapy in heart failure: a systematic review and meta-analysis

Background

The presence of left ventricular contractile reserve (LVCR) during stress echo (SE) may provide favorable response to cardiac resynchronization therapy (CRT) in heart failure patients. The aim of the study was to perform a meta-analysis of available SE data in this set of patients.

Methods

From a Pubmed and Advance Google Scholar database web based search scan up to December 2016, we initially identified 5906 records. From this initial set, we removed that did not include SE and duplicate studies. We assessed for eligibility 71 full-text articles assessed for eligibility, and 60 of them did not meet the inclusion criteria as follow: 1) heart failure patients with NYHA class III and IV, depressed ejection fraction (EF <35%) and QRS duration ≥120 ms at study entry; 2) SE with assessment of LVCR; 3) Follow-up data. LVCR during SE was identified as reduction in wall motion score index and/or an increase in EF.

Results

Eleven studies with 861 patients (mean age 67 ± 9 years, ejection fraction 25 ± 6%) were included in the meta-analysis. The type of stress was either exercise (n = 2) or dobutamine (n = 9), the latter with low-dose (10 mcg) in two, intermediate-dose (20 mcg) in five, and high-dose (40 mcg) protocol in two studies. LVCR was detected in 555 patients (63%) and CRT-response was present in 584 (66%). The overall odds ratio for LVCR to predict a favorable CRT response was 2.06 (95%, CI 1.70–2-43), Z score: 11.055, p < 0.001.

Conclusion

The presence of LVCR during SE with either dobutamine or exercise is associated with a greater chance of response to CRT. This parameter is now ready to be tested in a prospective multicenter trial to select patients more likely to benefit from CRT.

Neurocognitive Outcomes at 10 Years of Age in Extremely Preterm Newborns with Late-Onset Bacteremia

OBJECTIVE

To evaluate the difference in 10-year neurocognitive outcomes between extremely low gestational age newborns without bacteremia and those with suspected or confirmed late-onset bacteremia.

STUDY DESIGN

Neurocognitive function was evaluated at 10 years of age in 889 children born at <28 weeks of gestation and followed from birth. Definite (culture-positive) late-onset bacteremia during postnatal weeks 2-4 was identified in 223 children, and 129 children had suspected bacteremia.

RESULTS

Infants with the lowest gestational age and birth weight z-score had the highest prevalence of definite and suspected late-onset bacteremia. Compared with peers with no or suspected bacteremia, infants with definite bacteremia performed worse on tests of general cognitive ability, language, academic achievement, and executive function, even after adjustment for potential confounders. Adjustment for low IQ attenuated the associations between bacteremia and all dysfunctions at age 10 years. Children with suspected bacteremia did not differ appreciably from those with no evidence of bacteremia. The motor domain was unaffected.

CONCLUSIONS

Extremely low gestational age newborns who had definite late bacteremia during postnatal weeks 2-4 are at heightened risk of neurocognitive limitations at age 10 years.

Laparoscopic Excision Versus Ablation for Endometriosis-associated Pain: An Updated Systematic Review and Meta-analysis

The aim of this study was to update the evidence on the surgical management of endometriosis-associated pain. Does laparoscopic excision offer any benefits over laparoscopic ablation? This is a systematic review and meta-analysis in which we searched MEDLINE, Embase, Institute for Scientific Information conference proceedings, the International Standard Randomised Controlled Trial Number registry, the Register and Meta-register for randomized controlled trials, the World Health Organization trials search portal, the Cochrane Library, and the British Library of electronic theses. Three randomized controlled trials were included, which enrolled 335 participants with a sample size per study ranging from 24 to 178 participants. Of these 3 studies, data from 2 could be pooled for meta-analysis. The primary outcome measure was the reduction in the visual analog scale score for dysmenorrhea. The secondary outcome measures included the reduction in the visual analog scale score for dyspareunia, dyschezia, and chronic pelvic pain and the reduction in Endometriosis Health Profile-30 core pain scores. The meta-analysis showed that the excision group had a significantly greater reduction in symptoms of dysmenorrhea (mean difference [MD] = 0.99; 95% confidence interval [CI], -0.02 to 2.00; p = .05) and dyschezia (MD = 1.31; 95% CI, 0.33-2.29; p = .009) compared with ablation. The symptoms of dyspareunia showed a nonsignificant benefit with excision (MD = 0.96; 95% CI, -0.07 to 1.99; p = .07). Data from 1 study showed a significant reduction in chronic pelvic pain (MD = 2.57; 95% CI, 1.27-3.87; p = .0001) and Endometriosis Health Profile-30 core pain scores (MD = 13.20; 95% CI, 3.70-22.70; p = .006) with the excision group compared with the ablation group. The limited available evidence shows that at 12 months postsurgery, symptoms of dysmenorrhea, dyschezia, and chronic pelvic pain secondary to endometriosis showed a significantly greater improvement with laparoscopic excision compared with ablation.

Single- or double-unit UCBT following RIC in adults with AL: a report from Eurocord, the ALWP and the CTIWP of the EBMT

Background

The feasibility of cord blood transplantation (CBT) in adults is limited by the relatively low number of hematopoietic stem/progenitor cells contained in one single CB unit. The infusion of two CB units from different partially HLA-matched donors (double CBT) is frequently performed in patients who lack a sufficiently rich single CB unit.

Methods

We compared CBT outcomes in patients given single or double CBT following reduced-intensity conditioning (RIC) in a retrospective multicenter registry-based study. Inclusion criteria included adult (≥18 years) patients, acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL), complete remission (CR) at the time of transplantation, first single (with a cryopreserved TNC ≥ 2.5 × 10⁷/kg) or double CBT between 2004 and 2014, and RIC conditioning.

Results

Data from 534 patients with AML (n = 408) or ALL (n = 126) receiving a first single (n = 172) or double (n = 362) CBT were included in the analyses. In univariate analysis, in comparison to patients transplanted with a single CB, double CB recipients had a similar incidence of neutrophil engraftment but a suggestion for a higher incidence of grade II–IV acute GVHD (36 versus 28%, P = 0.08). In multivariate analyses, in comparison to single CBT recipients, double CBT patients had a comparable incidence of relapse (HR = 0.9, P = 0.5) and of nonrelapse mortality (HR = 0.8, P = 0.3), as well as comparable overall (HR = 0.8, P = 0.17), leukemia-free (HR = 0.8, P = 0.2) and GVHD-free, relapse-free (HR = 1.0, P = 0.3) survival.

Conclusions

These data failed to demonstrate better transplantation outcomes in adult patients receiving double CBT in comparison to those receiving single CBT with adequate TNC after RIC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-017-0497-9) contains supplementary material, which is available to authorized users.

Association between the HLA-B alleles and carbamazepine-induced SJS/TEN: A meta-analysis

PURPOSE

From our current understanding, the association between the human leukocyte antigen (HLA), HLA-B*1502, and carbamazepine(CBZ)-induced Stevens-Jonson syndrome and toxic epidermal necrolysis (SJS/TEN) in the Asian population is quite clear. However the relationship between other HLA-B alleles and CBZ-induced severe cutaneous adverse drug reactions (SCADRs) remains unclear. We aimed to identify other non-HLA-B*1502 alleles in patients with CBZ-induced SCADRs through a meta-analysis.

MATERIALS AND METHODS

A thorough literature search was performed using Embase, PubMed, Web of Knowledge and Cochrane databases. A meta-analysis was performed from their inceptions to May 31, 2016. Studies investigating the association of HLA-B alleles and CBZ-induced SJS/TEN were retrieved. Two reviewers independently extracted the data. Overall odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated using the RevMan 5.3 software.

RESULTS

A total of 11 studies met the inclusion criteria, totaling 343 CBZ-induced SJS/TEN cases, 838 CBZ tolerant controls, and 978 population controls. We observed HLA-B*1511 as a risk marker, and HLA-B*4001 and HLA-B*4601 as protective markers for the development of SJS/TEN in patients taking CBZ. SJS/TEN cases were found to be significantly associated with HLA-B*1511 in both the tolerant group (OR=17.43;95%CI=3.12-97.41;P=0.001) and the population-control group (OR=11.11; 95%CI=2.62-47.09; P=0.001). The sensitivity analysis found that HLA-B*5801 was a protective marker in the Southeast Asian population (OR=0.23; 95%CI=0.09-0.58; P=0.002).

CONCLUSION

Our study demonstrated that in the Asian population, HLA-B*4001, HLA-B*4601, HLA-B*5801 were strong protective factors in the development of CBZ-induced SJS/TEN whereas HLA-B*1511 was a risk factor. While more studies may be needed in order to confirm these findings, consideration should be taken into testing Asian patients for at-risk alleles prior to CBZ therapy initiation.

Chorioamnionitis in the Development of Cerebral Palsy: A Meta-analysis and Systematic Review

CONTEXT

Chorioamnionitis (CA) has often been linked etiologically to cerebral palsy (CP).

OBJECTIVES

To differentiate association from risk of CA in the development of CP.

DATA SOURCES

PubMed, Cochrane Library, Embase, and bibliographies of original studies were searched by using the keywords (chorioamnionitis) AND ((cerebral palsy) OR brain).

STUDY SELECTION

Included studies had to have: (1) controls, (2) criteria for diagnoses, and (3) neurologic follow-up. Studies were categorized based on: (1) finding incidence of CP in a CA population, or risk of CP; and (2) incidence of CA in CP or association with CP.

DATA EXTRACTION

Two reviewers independently verified study inclusion and extracted data.

RESULTS

Seventeen studies (125 256 CA patients and 5 994 722 controls) reported CP in CA. There was significantly increased CP inpreterm histologic chorioamnionitis (HCA; risk ratio [RR] = 1.34, P < .01), but not in clinical CA (CCA). Twenty-two studies (2513 CP patients and 8135 controls) reported CA in CP. There was increased CCA (RR = 1.43, P < .01), but no increase in HCA in preterm CP. Increased HCA was found (RR = 4.26, P < .05), as well as CCA in term/near-term CP (RR = 3.06, P < .01).

CONCLUSIONS

The evidence for a causal or associative role of CA in CP is weak. Preterm HCA may be a risk factor for CP, whereas CCA is not. An association with term and preterm CP was found for CCA, but only with term CP for HCA.

Neurocognitive Correlates of Attention-Deficit Hyperactivity Disorder Symptoms in Children Born at Extremely Low Gestational Age

OBJECTIVE

Compared with children born near term, those born extremely preterm (EP) are at much higher risk for attention-deficit hyperactivity disorder (ADHD). Little information is available about differences in neuropsychological outcomes among EP children with and without ADHD. Our analyses aimed to evaluate the neuropsychological correlates of ADHD symptoms in extremely low gestational age newborns (ELGANs).

METHODS

We obtained Child Symptom Inventory-4 reports from parents (n = 871) and teachers (n = 634) of 10-year-old children born before the 28th week of gestation. Participants completed standardized assessments of neurocognitive and academic functioning.

RESULTS

In the total sample, children who screened positive for ADHD symptoms were at increased risk for neurocognitive limitations. These associations were weaker when the sample was limited to those with intelligence quotient (IQ) ≥70 or ≥85. Even those with IQ ≥85 who screened positive for ADHD symptoms were more likely than their peers to have deficits on the DAS-II Working Memory Cluster and the NEPSY-II Auditory Response subtest. The risks for impaired academic performance (Z ≤ -1) on components of the WIAT-III were 2-to-3 times higher in this group than among ELGANs not classified as having ADHD symptoms.

CONCLUSION

Among children born EP, those with ADHD symptoms are more likely to have global neurocognitive impairment. When IQ is within normal limits, ADHD symptoms are associated with deficits in executive functioning skills. These findings highlight a group at risk for executive functioning deficits and related academic difficulties, even in the absence of intellectual disability.

The correlation of sperm morphology with unexplained recurrent spontaneous abortion: A systematic review and meta-analysis

Sperm morphology displays a potential impact on sperm function and may ultimately impact reproductive function. Current studies have investigated the correlation between sperm morphology with unexplained recurrent spontaneous abortion (RSA) but have shown inconsistent results. Hence, we systematically searched MEDLINE, EMBASE, CNKI databases, as well as the Cochrane Library for studies that examined the association between sperm morphology and unexplained RSA. Fifteen studies were identified, including 883 cases and 530 controls. Our meta-analysis results indicated that the percentage of normal sperm morphology from men with RSA partners was significantly lower than those from normal controls(SMD [95% CI]: - 0.60 [-0.81, -0.40]; P<0.00001) and the percentage of sperm morphologic alterations was significantly higher in patients with RSA compared with the control group (SMD [95% CI]: 0.92 [0.42, 1.43]; P=0.0004). The present study suggested that the percentage of normal sperm morphology may indeed decrease in men from RSA group compared with controls. However, there were some limitations in the study such as the differences in stain techniques and classification criteria. Further evidences are needed to better elucidate the relationship between sperm morphology and unexplained RSA.

The efficacy of probiotics as pharmacological treatment of cutaneous wounds: Meta-analysis of animal studies

The aim of the current meta-analysis of animal studies was to evaluate the efficacy of probiotics as pharmacological treatment of cutaneous wounds. A systematic electronic literature search was conducted and in total six animal studies which undertake twelve experiments met our inclusion criteria. We used the percentage (%) of wound area at the end of the first week after initial wounding to evaluate the efficacy of the probiotic treatment. The heterogeneity was estimated as statistically significant (p<0.0001) and therefore the meta-analysis was performed with the random-effect model. Based on the estimated Hedges' g (Hedges, 1982), the administration of probiotics was associated with acceleration of the wound contraction (g=-2.55; 95%CI=-3.59, -1.50; p<0.0001). The meta-regression analysis showed that the moderator sterile kefir extract has the greater effect on the overall estimated efficacy of probiotic treatment (g=-5.6983; p=0.0442) with bacteria probiotic therapies (70% kefir gel, L. brevis, L. fermentum, L. plantarum, L. reuteri) following (g=-2.3814; p=0.0003). For bacteria dose moderator, the results showed that increase in bacterial dose corresponds to increase of the estimated overall effect size (g=-10.2056; p=0.0053). The linear regression test of funnel plot asymmetry showed absence of publication bias. In conclusion, the results indicate that probiotics administration is an effective pharmacological treatment of cutaneous wounds. However, due to the heterogeneity among studies, further research is required.

What are the critical elements of sideline screening that can be used to establish the diagnosis of concussion? A systematic review

BACKGROUND

Sideline detection is the first and most significant step in recognising a potential concussion and removing an athlete from harm. This systematic review aims to evaluate the critical elements aiding sideline recognition of potential concussions including screening tools, technologies and integrated assessment protocols.

DATA SOURCES

Bibliographic databases, grey literature repositories and relevant websites were searched from 1 January 2000 to 30 September 2016. A total of 3562 articles were identified.

STUDY SELECTION

Original research studies evaluating a sideline tool, technology or protocol for sports-related concussion were eligible, of which 27 studies were included.

DATA EXTRACTION

A standardised form was used to record information. The QUADAS-2 and Newcastle-Ottawa tools were used to rate risk of bias. Strength of evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation Working Group system.

DATA SYNTHESIS

Studies assessing symptoms, the King-Devick test and multimodal assessments reported high sensitivity and specificity. Evaluations of balance and cognitive tests described lower sensitivity but higher specificity. However, these studies were at high risk of bias and the overall strength of evidence examining sideline screening tools was very low. A strong body of evidence demonstrated that head impact sensors did not provide useful sideline concussion information. Low-strength evidence suggested a multimodal, multitime-based concussion evaluation process incorporating video review was important in the recognition of significant head impact events and delayed onset concussion.

CONCLUSION

In the absence of definitive evidence confirming the diagnostic accuracy of sideline screening tests, consensus-derived multimodal assessment tools, such as the Sports Concussion Assessment Tool, are recommended. Sideline video review may improve recognition and removal from play of athletes who have sustained significant head impact events. Current evidence does not support the use of impact sensor systems for real-time concussion identification.

Burden of neurodevelopmental disorders in low and middle-income countries: A systematic review and meta-analysis

Background: Childhood mortality from infectious diseases has declined steadily in many low and middle-income (LAMIC) countries, with increased recognition of non-communicable diseases such as neurodevelopmental disorders (NDD). There is lack of data on the burden of NDD in LAMIC. Current global burden of these disorders are largely extrapolated from high-income countries. The main objective of the study was therefore to estimate the burden of NDD in LAMIC using meta-analytic techniques. Methods: We systematically searched online databases including Medline/PubMed, PsychoInfo, and Embase for studies that reported prevalence or incidence of NDD. Pooled prevalence, heterogeneity and risk factors for prevalence were determined using meta-analytic techniques.   Results: We identified 4,802 records, but only 51 studies met the eligibility criteria. Most studies were from Asia (52.2%) and most were on neurological disorders (63.1%). The median pooled prevalence per 1,000 for all NDD was 7.6 (95%CI 7.5-7.7), being 11.3 (11.7-12.0) for neurological disorders and 3.2 (95%CI 3.1-3.3) for mental conditions such as attention-deficit hyperactivity disorder (ADHD). The type of NDD was significantly associated with the greatest prevalence ratio in the multivariable model (PR=2.6(95%CI 0.6-11.6) (P>0.05). Incidence was only reported for epilepsy (mean of 447.7 (95%CI 415.3-481.9) per 100,000). Perinatal complications were the commonest risk factor for NDD. Conclusion: The burden of NDD in LAMIC is considerable. Epidemiological surveys on NDD should screen all types of NDD to provide reliable estimates.

Implementation of study results in guidelines and adherence to guidelines in clinical practice

Guidelines were introduced in hospital- and practice-based otorhinolaryngology in the 1990ies, and have been undergoing further development ever since. There are currently 20 guidelines on file at the German Society of Oto-Rhino-Laryngology, Head & Neck Surgery. The society has cooperated in further 34 guidelines. The quality of the guidelines has been continuously improved by concrete specifications put forward by the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e.V., AWMF). Since increasing digitalization has made access to scientific publications quicker and simpler, relevant study results can be incorporated in guidelines more easily today than in the analog world. S2e and S3 guidelines must be based on a formal literature search with subsequent evaluation of the evidence. The consensus procedure for S2k guidelines is also regulated. However, the implementation of guidelines in routine medical practice must still be considered inadequate, and there is still a considerable need for improvement in adherence to these guidelines.

Long-term impact of sewage sludge application on soil microbial biomass: An evaluation using meta-analysis

The Long-Term Sludge Experiments (LTSE) began in 1994 as part of continuing research into the effects of sludge-borne heavy metals on soil fertility. The long-term effects of Zn, Cu, and Cd on soil microbial biomass carbon (C_mic) were monitored for 8 years (1997-2005) in sludge amended soils at nine UK field sites. To assess the statutory limits set by the UK Sludge (Use in Agriculture) Regulations the experimental data has been reviewed using the statistical methods of meta-analysis. Previous LTSE studies have focused predominantly on statistical significance rather than effect size, whereas meta-analysis focuses on the magnitude and direction of an effect, i.e. the practical significance, rather than its statistical significance. The results presented here show that significant decreases in C_mic have occurred in soils where the total concentrations of Zn and Cu fall below the current UK statutory limits. For soils receiving sewage sludge predominantly contaminated with Zn, decreases of approximately 7-11% were observed at concentrations below the UK statutory limit. The effect of Zn appeared to increase over time, with increasingly greater decreases in C_mic observed over a period of 8 years. This may be due to an interactive effect between Zn and confounding Cu contamination which has augmented the bioavailability of these metals over time. Similar decreases (7-12%) in C_mic were observed in soils receiving sewage sludge predominantly contaminated with Cu; however, C_mic appeared to show signs of recovery after a period of 6 years. Application of sewage sludge predominantly contaminated with Cd appeared to have no effect on C_mic at concentrations below the current UK statutory limit.

Chlorhexidine bathing and health care-associated infections among adult intensive care patients: a systematic review and meta-analysis

Background

Health care-associated infections (HAI) have been shown to increase length of stay, the cost of care, and rates of hospital deaths (Kaye and Marchaim, J Am Geriatr Soc 62(2):306–11, 2014; Roberts and Scott, Med Care 48(11):1026–35, 2010; Warren and Quadir, Crit Care Med 34(8):2084–9, 2006; Zimlichman and Henderson, JAMA Intern Med 173(22):2039–46, 2013). Importantly, infections acquired during a hospital stay have been shown to be preventable (Loveday and Wilson, J Hosp Infect 86:S1–70, 2014). In particular, due to more invasive procedures, mechanical ventilation, and critical illness, patients cared for in the intensive care unit (ICU) are at greater risk of HAI and associated poor outcomes. This meta-analysis aims to summarise the effectiveness of chlorhexidine (CHG) bathing, in adult intensive care patients, to reduce infection.

Methods

A systematic literature search was undertaken to identify trials assessing the effectiveness of CHG bathing to reduce risk of infection, among adult intensive care patients. Infections included were: bloodstream infections; central line-associated bloodstream infections (CLABSI); catheter-associated urinary tract infections; ventilator-associated pneumonia; methicillin-resistant Staphylococcus aureus (MRSA); vancomycin-resistant Enterococcus; and Clostridium difficile. Summary estimates were calculated as incidence rate ratios (IRRs) and 95% confidence/credible intervals. Variation in study designs was addressed using hierarchical Bayesian random-effects models.

Results

Seventeen trials were included in our final analysis: seven of the studies were cluster-randomised crossover trials, and the remaining studies were before-and-after trials. CHG bathing was estimated to reduce the risk of CLABSI by 56% (Bayesian random effects IRR = 0.44 (95% credible interval (CrI), 0.26, 0.75)), and MRSA colonisation and bacteraemia in the ICU by 41% and 36%, respectively (IRR = 0.59 (95% CrI, 0.36, 0.94); and IRR = 0.64 (95% CrI, 0.43, 0.91)). The numbers needed to treat for these specific ICU infections ranged from 360 (CLABSI) to 2780 (MRSA bacteraemia).

Conclusion

This meta-analysis of the effectiveness of CHG bathing to reduce infections among adults in the ICU has found evidence for the benefit of daily bathing with CHG to reduce CLABSI and MRSA infections. However, the effectiveness may be dependent on the underlying baseline risk of these events among the given ICU population. Therefore, CHG bathing appears to be of the most clinical benefit when infection rates are high for a given ICU population.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1553-5) contains supplementary material, which is available to authorized users.

Methods for estimating the burden of antimicrobial resistance: a systematic literature review protocol

BACKGROUND

Estimates of the burden of antimicrobial resistance (AMR) are needed to ascertain AMR impact, to evaluate interventions, and to allocate resources efficiently. Recent studies have estimated health, cost, and economic burden relating to AMR, with outcomes of interest ranging from drug-bug resistance impact on mortality in a hospital setting to total economic impact of AMR on the global economy. However, recent collation of this information has been largely informal, with no formal quality assessment of the current evidence base (e.g. with predefined checklists). This review therefore aims to establish what perspectives and resulting methodologies have been used in establishing the burden of AMR, whilst also ascertaining the quality of these studies.

METHODS

The literature review will identify relevant literature using a systematic review methodology. MEDLINE, EMBASE, Scopus and EconLit will be searched utilising a predefined search string. Grey literature will be identified by searching within a predefined list of organisational websites. Independent screening of retrievals will be performed in a two-stage process (abstracts and full texts), utilising a pre-defined inclusion and exclusion criteria. Data will be extracted into a data extraction table and descriptive examination will be performed. Study quality will be assessed using the Newcastle-Ottawa scales and the Philips checklists where appropriate. A narrative synthesis of the results will be presented.

DISCUSSION

This review will provide an overview of previous health, cost and economic definitions of burden and the resultant impact of these different definitions on the burden of AMR estimated. The review will also explore the methods that have been used to calculate this burden and discuss resulting study quality. This review can therefore act as a guide to methods for future research in this area.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037510.

The c.553G>T Genetic Variant of the APOA5 Gene and Altered Triglyceride Levels in the Asian Population: A Meta-Analysis of Case-Control Studies

AIM

To explore the association of the APOA5 gene c.553G>T polymorphism with hypertriglyceridemia (HTG) susceptibility and altered triglyceride levels.

METHODS

We searched the PubMed, Google Scholar, and CNKI databases for published studies relating to analyses of these associations. Case-control and comparative studies of the association between the APOA5 c.553G>T variant and altered triglyceride levels were included. In total, the meta-analysis involved 10 studies on HTG, which provided 2219 cases and 3401 controls. To measure the correlation between the c.553G>T polymorphism and HTG susceptibility, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The overall OR was calculated using a random-effects model.

RESULTS

Compared with APOA5 c.553 GG carriers, c.553T carriers displayed an increased risk of HTG in the Asian population, with an overall random effects OR of 3.55 (95% CI: 2.46-5.13) in the dominant model. There was significant heterogeneity among the studies (P_{heterogeneity}: Chi² = 45.80, I² = 75.98%), which may be largely explained by certain patient types. Both the sensitivity analysis and publication bias suggested that the overall result was acceptable. Subgroup analysis showed a large difference in serum triglyceride levels based on the c.553 G > T polymorphism in healthy individuals and HTG patients. APOA5 c.553T carriers exhibit higher triglyceride levels than GG carriers.

CONCLUSION

Our results suggest that APOA5 c. 553T is an independent risk factor for HTG and increased triglyceride levels in the Asian population. APOA5 c. 553T could be employed as a genetic risk marker for HTG and increased triglyceride levels.

Graphics and Statistics for Cardiology: Data visualisation for meta-analysis

Graphical displays play a pivotal role in understanding data sets and disseminating results. For meta-analysis, they are instrumental in presenting findings from multiple studies. This report presents guidance to authors wishing to submit graphical displays as part of their meta-analysis to a clinical cardiology journal, such as HeartWhen using graphical displays for meta-analysis, we recommend the following: Use a flow diagram to describe the number of studies returned from the initial search, the inclusion/exclusion criteria applied and the final number of studies used in the meta-analysis.Present results from the meta-analysis using a figure that incorporates a forest plot and underlying (tabulated) statistics, including test for heterogeneity.Use displays such as funnel plot (minimum 10 studies) and Galbraith plot to visually present distribution of effect sizes or associations in order to evaluate small-study effects and publication bias).For meta-regression, the bubble plot is a useful display for assessing associations by study-level factors.Final checks on graphs, such as appropriate use of axis scale, line pattern, text size and graph resolution, should always be performed.

Potential for Meta-Analysis in the Realm of Preharvest Food Safety

Meta-analysis, the statistical combination of results from multiple studies, can be used to summarize all of the available research on an intervention, etiology, descriptive, or diagnostic test accuracy question. Meta-analysis should be conducted as a component of a systematic review, to increase transparency in the selection of studies and to incorporate an evaluation of the risk of bias in the individual studies included in the meta-analysis. The process of meta-analysis may include a forest plot to graphically display the study results and the calculation of a weighted average summary effect size. Heterogeneity (differences in the effect size between studies) can be evaluated using formal statistics and the reasons for heterogeneity can be explored using sub-group analysis or meta-regression. Thus, meta-analysis may be a useful methodology for preharvest food safety research to aid in policy or clinical decision-making or to provide input to quantitative risk assessment or other models.

Systematic reviews and meta-analyses in spine surgery, neurosurgery and orthopedics: guidelines for the surgeon scientist

The research evidence in the realm of surgery is expanding at a rapid pace, and thus corresponds with an increasing need to critically appraise and synthesize the available literature. Particularly in fields such as spine surgery, neurosurgery and orthopedics which traditionally have little Class I randomized clinical data, reviews are important to pool the available evidence on clinical questions which are otherwise difficult to answer. Whilst systematic reviews and meta-analyses have the potential to provide critical and updated surgical evidence to guide clinical decisions, poorly performed analyses and misinterpretation of such reviews may have a detrimental effect on patient care and outcomes. We present a summary of the critical steps in performing a systematic review and meta-analysis, allowing the surgeon scientist to better interpret and perform their own systematic reviews and meta-analyses.

Individualized Hydrocodone Therapy Based on Phenotype, Pharmacogenetics, and Pharmacokinetic Dosing

OBJECTIVES

(1) To quantify hydrocodone (HC) and hydromorphone (HM) metabolite pharmacokinetics with pharmacogenetics in CYP2D6 ultra-rapid metabolizer (UM), extensive metabolizer (EM), and poor metabolizer (PM) metabolizer phenotypes. (2) To develop an HC phenotype-specific dosing strategy for HC that accounts for HM production using clinical pharmacokinetics integrated with pharmacogenetics for patient safety.

SETTING

In silico clinical trial simulation.

PARTICIPANTS

Healthy white men and women without comorbidities or history of opioid, or any other drug or nutraceutical use, age 26.3±5.7 years (mean±SD; range, 19 to 36 y) and weight 71.9±16.8 kg (range, 50 to 108 kg).

MAIN OUTCOME MEASURES

CYP2D6 phenotype-specific HC clinical pharmacokinetic parameter estimates and phenotype-specific percentages of HM formed from HC.

RESULTS

PMs had lower indices of HC disposition compared with UMs and EMs. Clearance was reduced by nearly 60% and the t1/2 was increased by about 68% compared with EMs. The canonical order for HC clearance was UM>EM>PM. HC elimination mainly by the liver, represented by ke, was reduced about 70% in PM. However, HC's apparent Vd was not significantly different among UMs, EMs, and PM. The canonical order of predicted plasma HM concentrations was UM>EM>PM. For each of the CYP2D6 phenotypes, the mean predicted HM levels were within HM's therapeutic range, which indicates HC has significant phenotype-dependent pro-drug effects.

CONCLUSIONS

Our results demonstrate that pharmacogenetics afford clinicians an opportunity to individualize HC dosing, while adding enhanced opportunity to account for its conversion to HM in the body.

Current and Evolving Methods to Visualize Biological Data in Cancer Research

Although the measurements of clinical outcomes for cancer treatments have become diverse and complex, there remains a need for clear, easily interpreted representations of patients' experiences. With oncology trials increasingly reporting non-time-to-event outcomes, data visualization has evolved to incorporate parameters such as responses to therapy, duration and degree of response, and novel representations of underlying tumor biology. We review both commonly used and newly developed methods to display outcomes in oncology, with a focus on those that have evolved to represent complex datasets.

Perioperative Dextromethorphan as an Adjunct for Postoperative Pain: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

N-methyl-D-aspartate receptor antagonists have been shown to reduce perioperative pain and opioid use. The authors performed a meta-analysis to determine whether the use of perioperative dextromethorphan lowers opioid consumption or pain scores.

METHODS

PubMed, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Pubget, and EMBASE were searched. Studies were included if they were randomized, double-blinded, placebo-controlled trials written in English, and performed on patients 12 yr or older. For comparison of opioid use, included studies tracked total consumption of IV or intramuscular opioids over 24 to 48 h. Pain score comparisons were performed at 1, 4 to 6, and 24 h postoperatively. Difference in means (MD) was used for effect size.

RESULTS

Forty studies were identified and 21 were eligible for one or more comparisons. In 848 patients from 14 trials, opioid consumption favored dextromethorphan (MD, -10.51 mg IV morphine equivalents; 95% CI, -16.48 to -4.53 mg; P = 0.0006). In 884 patients from 13 trials, pain at 1 h favored dextromethorphan (MD, -1.60; 95% CI, -1.89 to -1.31; P < 0.00001). In 950 patients from 13 trials, pain at 4 to 6 h favored dextromethorphan (MD, -0.89; 95% CI, -1.11 to -0.66; P < 0.00001). In 797 patients from 12 trials, pain at 24 h favored dextromethorphan (MD, -0.92; 95% CI, -1.24 to -0.60; P < 0.00001).

CONCLUSION

This meta-analysis suggests that dextromethorphan use perioperatively reduces the postoperative opioid consumption at 24 to 48 h and pain scores at 1, 4 to 6, and 24 h.

A corpus of potentially contradictory research claims from cardiovascular research abstracts

Background

Research literature in biomedicine and related fields contains a huge number of claims, such as the effectiveness of treatments. These claims are not always consistent and may even contradict each other. Being able to identify contradictory claims is important for those who rely on the biomedical literature. Automated methods to identify and resolve them are required to cope with the amount of information available. However, research in this area has been hampered by a lack of suitable resources. We describe a methodology to develop a corpus which addresses this gap by providing examples of potentially contradictory claims and demonstrate how it can be applied to identify these claims from Medline abstracts related to the topic of cardiovascular disease.

Methods

A set of systematic reviews concerned with four topics in cardiovascular disease were identified from Medline and analysed to determine whether the abstracts they reviewed contained contradictory research claims. For each review, annotators were asked to analyse these abstracts to identify claims within them that answered the question addressed in the review. The annotators were also asked to indicate how the claim related to that question and the type of the claim.

Results

A total of 259 abstracts associated with 24 systematic reviews were used to form the corpus. Agreement between the annotators was high, suggesting that the information they provided is reliable.

Conclusions

The paper describes a methodology for constructing a corpus containing contradictory research claims from the biomedical literature. The corpus is made available to enable further research into this area and support the development of automated approaches to contradiction identification.

The effect of intrauterine HCG injection on IVF outcome: a systematic review and meta-analysis

In this systematic review and meta-analysis, the effect of intrauterine HCG infusion before embryo transfer on IVF outcomes (live birth rate, clinical pregnancy rate and spontaneous aboretion rate) was investigated. Searches were conducted on MEDLINE, EMBASE and The Cochrane Library. Randomized studies in women undergoing IVF and intracytoplasmic sperm injection comparing intrauterine HCG administration at embryo transfer compared with no intrauterine HCG were eligible for inclusion. Eight randomized controlled trials were eligible for inclusion in the meta-analysis. A total of 3087 women undergoing IVF and intracytoplasmic sperm injection cycles were enrolled (intrauterine HCG group: n = 1614; control group: n = 1473). No significant difference was found in the live birth rate (RR 1.13; 95% CI 0.84 to 1.53) and spontaneous abortion rate (RR 1.00, 95% CI 0.74 to 1.34) between women who received intrauterine HCG and those who did not receive HCG. Although this review was extensive and included randomized controlled trials, no significant heterogeneity was found, and the overall included numbers are relatively small. In conclusion the current evidence does not support the use of intrauterine HCG administration before embryo transfer. Well-designed multicentre trials are needed to provide robust evidence.

Brivaracetam Population Pharmacokinetics and Exposure-Response Modeling in Adult Subjects With Partial-Onset Seizures

Brivaracetam is a selective high-affinity ligand for synaptic vesicle protein 2A, recently approved as adjunctive therapy in the treatment of partial-onset (focal) seizures in patients 16 years of age and older with epilepsy. A population pharmacokinetic (PK) model and a population pharmacokinetic/pharmacodynamic (PKPD) model were developed describing brivaracetam plasma concentration and the relationship with daily seizure counts in adequate well-controlled efficacy trials. The effect of body weight on clearance and volume was implemented using allometric scaling, and a range of covariates were investigated for their influence on brivaracetam clearance. The PKPD model described daily seizure counts using a negative binomial distribution, taking previous day seizures into account, and using a mixture model to separate "placebo-like" and "response" subpopulations. The PK and PKPD models provided a good description of the data, documented using visual predictive checks. Coadministration with carbamazepine, phenytoin, and phenobarbital decreased brivaracetam exposure by 26%, 21%, and 19%, respectively, without significant effects on PD response. Covariate analysis indicated that levetiracetam coadministration reduced the fraction of subjects in the mixture model response population to 4% and identified baseline seizure frequency as a strong predictor for being assigned to the mixture model response population. Simulation allowed characterization of the dose-response curve, suggesting maximum response is obtained at brivaracetam 150-200 mg/day.

Positive penicillin allergy testing results: a systematic review and meta-analysis of papers published from 2010 through 2015

β-lactam antibiotics are the most widely used group of antibiotics, given their effectiveness for the most common bacterial pathogens and their relatively low price. Adverse reactions, mainly cutaneous, are often reported to be associated with their use and hence, less effective and usually more costly alternative antibiotics are prescribed. However, it is not clear what is the risk of immediate immune-mediated (i.e. developing within one hour of administration) and potentially life-threatening reactions among those using β-lactam antibiotic. We conducted a systematic review to assess the prevalence of immediate adverse reactions to β-lactam antibiotics, specifically penicillin derivatives, in patients with a reported adverse reaction to β-lactam antibiotics. In addition, we determined the effect of age on the prevalence of immediate reactions. Assessing the true risk of using β-lactam antibiotics in patients with a reported allergy could prevent physicians from unnecessarily discouraging the use of β-lactam antibiotics. We conducted a systematic review and a meta-analysis using the PubMed, OVID, and Embase databases of work published in English and in French in the last 5 years. Studies were only eligible if they established the prevalence of immediate penicillin reactions with skin testing or challenges in case of negative skin tests. The meta-analysis was conducted using Stata version 12.0. The prevalence of immediate reactions to penicillin derivatives in patients reporting a β-lactam hypersensitivity is 1.98% (95%CI; 1.35%, 2.60%) in the pediatric (under 18 years old) group, 7.78% (95%CI; 6.53%, 9.04%) in the adult group, and 2.84% (95%CI; 1.77%, 3.91%) in the combined group, as tested in various studies, using skin tests and oral challenges. The I(2) value ranged between 87.2% and 97.0%. Our results indicate that the prevalence of immediate reactions is higher in adults than in children. However, wide confidence intervals and a large study heterogeneity preclude conclusive estimates.

Radiotherapy concurrent versus sequential with endocrine therapy in breast cancer: A meta-analysis

INTRODUCTION

This study compared treatment outcomes of radiotherapy concurrent with endocrine therapy and radiotherapy sequential with endocrine therapy in breast cancer.

MATERIALS AND METHODS

Eligible studies of radiotherapy concurrent and sequential with endocrine therapy in breast cancer were retrieved through extensive searches of the PubMed, Medline, Embase, Cochrane library, FEBM, FMJS, Web of science, Wiley, CBM, CNKI, Wang fang, Cqvip databases from 2000 to 2014. Original English and Chinese publications of radiotherapy concurrent and sequential with endocrine therapy in breast cancer were included. The primary endpoint was radiation-induced toxicity including upper than grade 2 skin related toxicity, radiation pneumonia and pulmonary fibrosis; the second endpoint was survival date, including local recurrence, distant metastasis, 5-year OS, 10-year OS.

RESULTS

Eleven eligible trials were identified, six in English and five in Chinese. Totally, there were 1291 women in concurrent groups, and 1179 in sequential groups. Statistical analysis showed that there was no statistical difference between concurrent and sequential groups in skin related toxicity (RR 1.20, 95% CI 0.92-1.56, P = 0.17), radiation pneumonia (RR 1.11, 95% CI 0.46-2.70, P = 0.81) and pulmonary fibrosis (RR 1.35, 95% CI 0.75-2.41, P = 0.32). Meanwhile, no statistical difference was found in survival data, (RR 0.97, 95% CI 0.79-1.28, P = 0.26), (RR 0.86, 95% CI 0.66-1.12, P = 0.27) in local recurrence and distant metastasis respectively, (RR 1.01, 95% CI 0.96-1.06, P = 0.65), (RR 0.98, 95% CI 0.93-1.02, P = 0.32) in 5-year and 10-year overall survival respectively. Stratification analysis was proceeded, grouped by tamoxifen and AI in different treatment timing, however, no statistical difference was found in radiation-induced toxicity and survival outcomes.

CONCLUSION

Radiotherapy concurrent with endocrine therapy didn't increase or decrease neither the incidence of radiation-induced toxicity nor the survival rate compared with that of sequential group; Endocrine therapy drugs didn't influence outcomes in different treatment timing.

A Systematic Review of Meta-analyses Published in Arthroscopy: The Journal of Arthroscopic and Related Surgery

PURPOSE

To determine whether the number of meta-analyses published by Arthroscopy: The Journal of Arthroscopic and Related Surgery has increased from the inception of the Journal through 2014.

METHODS

A literature search of the Journal's Web site and Medline was carried out. All studies described as a "meta-analysis" as well as systematic reviews that pooled data were included. The number of published meta-analyses was calculated and summarized by year of publication, region, topic, and level of evidence.

RESULTS

The Journal's Web site search resulted in 517 citations for review, and the Medline search resulted in 400. After the results of each search were combined and duplicates were removed, a total of 60 studies were included in this review. The first published meta-analysis appeared in 2001. Of the 60 meta-analyses, 36 (60%) were published between 2013 and 2014. In light of the increase in the number of publications, a review of the design and conduct of a meta-analysis is presented in a straightforward question-and-answer format.

CONCLUSIONS

The number of meta-analyses appearing in Arthroscopy has increased over the past 2 decades. This increase highlights the importance of developing an understanding of the premise and components of a meta-analysis to allow the reader to critically appraise these studies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through IV meta-analyses.

Neonatal mortality and outcome at the end of the first year of life in early onset urea cycle disorders--review and meta-analysis of observational studies published over more than 35 years

BACKGROUND

For urea cycle disorders (UCD), proportions and mortality of early onset (EO) patients, as well as outcome at one year of life show large variability. We aimed to integrate available evidence to create benchmarks for new diagnostic and therapeutic strategies.

METHODS

Medline search for reports published between 1978 and Dec 22, 2014 was completed by hand search. Random effects meta-analysis was done for four UCDs, deficiency of carbamylphosphate synthetase 1 (CPS1D), male/female ornithine transcarbamylase (OTCDm/f), argininosuccinate synthetase (ASSD) and lyase (ASLD). Effects of publication year and geographic area were analysed by meta-regression.

RESULTS

Twenty-four publications report onset time (n = 1542 patients), survival of EO (n = 665 patients) and outcome at one year of life (n = 172 patients). Proportions for EO manifestation (95% confidence interval) were: CPS1D = 0.75 (0.61;0.88); OTCDm = 0.52 (0.39;0.65); OTCDf = 0.07 (0.03;0.11); ASSD = 0.65 (0.57;0.73); ASLD = 0.60 (0.44;0.77); for surviving EO patients: CPS1D = 0.64 (0.50;0.79); OTCDm = 0.40 (0.16;0.64); OTCDf = 0.57 (0.29;0.85); ASSD = 0.67 (0.48;0.86); ASLD = 0.81 (0.68;0.94); and for normal outcome at one year for survivors: CPS1D = 0.20 (0.07;0.38); OTCDm = 0.15 (0.00;0.39); OTCDf no data; ASSD = 0.36 (0.13;0.60); ASLD = 0.36 (0.17;0.58). Between study variation was large. Year of publication had no effect. Studies from Europe showed lower survival rates than those from Japan or USA.

CONCLUSIONS

UCDs, except for OTCDf, have high risks of EO disease manifestation and, except for ASLD, of neonatal death. No improvement of survival was observed over more than three decades. Geographic variation remains to be explained. This comprehensive description of the natural history of EO UCDs should be considered by scientists, clinicians, health policy makers and guideline developers.

Strategies designed to help healthcare professionals to recruit participants to research studies

BACKGROUND

Identifying and approaching eligible participants for recruitment to research studies usually relies on healthcare professionals. This process is sometimes hampered by deliberate or inadvertent gatekeeping that can introduce bias into patient selection.

OBJECTIVES

Our primary objective was to identify and assess the effect of strategies designed to help healthcare professionals to recruit participants to research studies.

SEARCH METHODS

We performed searches on 5 January 2015 in the following electronic databases: Cochrane Methodology Register, CENTRAL, MEDLINE, EMBASE, CINAHL, British Nursing Index, PsycINFO, ASSIA and Web of Science (SSCI, SCI-EXPANDED) from 1985 onwards. We checked the reference lists of all included studies and relevant review articles and did citation tracking through Web of Science for all included studies.

SELECTION CRITERIA

We selected all studies that evaluated a strategy to identify and recruit participants for research via healthcare professionals and provided pre-post comparison data on recruitment rates.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results for potential eligibility, read full papers, applied the selection criteria and extracted data. We calculated risk ratios for each study to indicate the effect of each strategy.

MAIN RESULTS

Eleven studies met our eligibility criteria and all were at medium or high risk of bias. Only five studies gave the total number of participants (totalling 7372 participants). Three studies used a randomised design, with the others using pre-post comparisons. Several different strategies were investigated. Four studies examined the impact of additional visits or information for the study site, with no increases in recruitment demonstrated. Increased recruitment rates were reported in two studies that used a dedicated clinical recruiter, and five studies that introduced an automated alert system for identifying eligible participants. The studies were embedded into trials evaluating care in oncology mainly but also in emergency departments, diabetes and lower back pain.

AUTHORS' CONCLUSIONS

There is no strong evidence for any single strategy to help healthcare professionals to recruit participants in research studies. Additional visits or information did not appear to increase recruitment by healthcare professionals. The most promising strategies appear to be those with a dedicated resource (e.g. a clinical recruiter or automated alert system) for identifying suitable participants that reduced the demand on healthcare professionals, but these were assessed in studies at high risk of bias.

The Many Flavors of Model-Based Meta-Analysis: Part I-Introduction and Landmark Data

Meta-analysis is an increasingly important aspect of drug development as companies look to benchmark their own compounds with the competition. There is scope to carry out a wide range of analyses addressing key research questions from preclinical through to postregistration. This set of tutorials will take the reader through key model-based meta-analysis (MBMA) methods with this first installment providing a general introduction before concentrating on classical and Bayesian methods for landmark data.

Graphics and statistics for cardiology: comparing categorical and continuous variables

Graphs are a standard tool for succinctly describing data, and play a crucial role supporting statistical analyses of that data. However, all too often, graphical display of data in submitted manuscripts is either inappropriate for the task at hand or poorly executed, requiring revision prior to publication. To assist authors, in this paper, we present several forms of graph, for data typically seen in Heart, including dot charts, violin plots, histograms and boxplots for quantitative data, and mosaic plots and bar charts for categorical data. Justification for using these specific plots is drawn from the literature on visual perception; we also provide software instruction and examples, using various popular packages.

The Glioma International Case-Control Study: A Report From the Genetic Epidemiology of Glioma International Consortium

Decades of research have established only a few etiological factors for glioma, which is a rare and highly fatal brain cancer. Common methodological challenges among glioma studies include small sample sizes, heterogeneity of tumor subtypes, and retrospective exposure assessment. Here, we briefly describe the Glioma International Case-Control (GICC) Study (recruitment, 2010-2013), a study being conducted by the Genetic Epidemiology of Glioma International Consortium that integrates data from multiple data collection sites, uses a common protocol and questionnaire, and includes biospecimen collection. To our knowledge, the GICC Study is the largest glioma study to date that includes collection of blood samples, which will allow for genetic analysis and interrogation of gene-environment interactions.

Comparison of Treatment Effects Between US and Non-US Study Sites in Multiregional Alzheimer Disease Clinical Trials

BACKGROUND

Conducting clinical trials across multiple regions of the world has become common practice. A multiregional clinical trial (MRCT) presents opportunities as well as challenges. However, regional differences of treatment effects appear in many MRCTs, which make the interpretation of clinical trial results difficult and presents challenges for clinical trial design. Alzheimer disease (AD) is a progressive neurodegenerative disorder that affects approximately 5 million people in the United States and is the sixth leading cause of death in the country. In 2014, AD cost the United States $214 billion, and the cost is expected to rise to $1.2 trillion by 2050.

METHODS

In this article, we utilize data from New Drug Applications (NDAs) that have been approved for the treatment of AD to study whether there are differences in treatment effect between US and non-US study sites. Using an analysis of covariance (ANCOVA) model and forest plot, we analyze the treatment difference by region (US and non-US) from 3 separate perspectives: by region for each trial, by region for each endpoint, and by region and trial for each endpoint.

RESULTS

Overall, the analyses indicate that treatment effects in clinical trials for AD are generally in the expected direction in both US and non-US sites. There was no clear evidence of heterogeneity in treatment effects between US and non-US sites.

CONCLUSIONS

It appears that there is no clear evidence to suggest that MRCTs should not be used to study AD.

Independent risk factors for mortality in patients with chronic obstructive pulmonary disease who undergo comprehensive cardiac evaluations

BACKGROUND

Cardiovascular disease is the most common cause of death in chronic obstructive pulmonary disease (COPD). However, the impact of cardiovascular comorbidities on the prognosis of COPD is not well known.

OBJECTIVES

This study was performed to investigate the effects of cardiovascular comorbidities on the prognosis of COPD.

METHODS

We enlisted 229 patients with COPD who underwent comprehensive cardiac evaluations including coronary angiography and echocardiography at Ajou University Hospital between January 2000 and December 2012. Survival analyses were performed in this retrospective cohort.

RESULTS

Kaplan-Meier analyses showed that COPD patients without left heart failure (mean survival = 12.5 ± 0.7 years) survived longer than COPD patients with left heart failure (mean survival = 6.7 ± 1.4 years; p = 0.003), and the survival period of nonanemic COPD patients (mean survival = 13.8 ± 0.8 years) was longer than that of anemic COPD patients (mean survival = 8.3 ± 0.8 years; p < 0.001). The survival period in COPD with coronary artery disease (CAD; mean survival = 11.37 ± 0.64 years) was not different from that in COPD without CAD (mean survival = 11.98 ± 0.98 years; p = 0.703). According to a multivariate Cox regression model, a lower hemoglobin level, a lower left ventricular ejection fraction, and the forced expiratory volume in 1 s (FEV1) were independently associated with higher mortality in the total COPD group (p < 0.05).

CONCLUSIONS

Hemoglobin levels and left ventricular ejection fraction along with a lower FEV1 were identified as independent risk factors for mortality in COPD patients who underwent comprehensive cardiac evaluations, suggesting that multidisciplinary approaches are required in the care of COPD.

Is Nintendo Wii an Effective Intervention for Individuals With Stroke? A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate the effectiveness of Nintendo Wii compared with no intervention or other exercise interventions in the rehabilitation of adults with stroke.

DATA SOURCES

Seven electronic databases were systematically searched to source for full-text studies published in peer-reviewed journals up to July 2014. Hand searches of reference lists were performed.

STUDY SELECTION

Randomized controlled trials (RCTs) comparing Wii with no intervention or other exercise interventions, in patients with stroke, were selected.

DATA EXTRACTION

Methodological quality was assessed by 2 independent reviewers. Data pertaining to participants, interventions, outcomes, and clinical effectiveness were independently extracted by 2 reviewers using a standardized form and compared for accuracy. We calculated mean or standardized mean differences for analysis of continuous variables. Risk ratios were derived and 95% confidence intervals (CIs) calculated.

DATA SYNTHESIS

Six studies were included. Three trials (64 participants) compared Wii and conventional rehabilitation versus conventional rehabilitation alone. Three trials (102 participants) compared Wii with other exercise interventions. The addition of Wii to conventional rehabilitation resulted in significant mean differences in favor of additional Wii compared with standard care for Timed Up and Go test (TUG) (0.81 points, CI 0.29-1.33, P = .002), but not for other mobility and functional outcomes: Functional Independence Measure (FIM) score (0.45, CI -0.21-1.11, P = .18), Berg Balance Score (-0.64, CI -3.66-2.39, P = .68), anteroposterior postural sway (0.23, CI -0.38-0.84, P = .46). No serious adverse events were reported, and when Wii was compared with exercise alone, we demonstrated a decreased risk of participants dropping out of follow-up (RR 0.40, CI 0.20-0.78, P = .007).

CONCLUSIONS

The addition of Wii gaming to conventional rehabilitation in patients with chronic stroke significantly improved performance in TUG and not in the other physical measures. The pooled effect was small and not beyond the minimal detectable change. However, Wii can be used safely in patients with stroke and participants were less likely to drop out in the Wii group. This review highlights the need for further high-quality studies to demonstrate the efficacy of Wii in stroke rehabilitation.

Population pharmacokinetics of dolutegravir in HIV-infected treatment-naive patients

Aim

Dolutegravir is the newest integrase inhibitor approved for HIV treatment and has demonstrated potent antiviral activity in patient populations with a broad range of treatment experience. This analysis aimed to characterize the population pharmacokinetics of dolutegravir in treatment-naive patients and to evaluate the influence of patient covariates.

Methods

A population pharmacokinetic model was developed using a non-linear mixed effect modelling approach based on data from 563 HIV-infected, treatment-naive adult patients in three phase 2/3 trials who received dolutegravir (ranging from 10–50 mg once daily) alone or in combination with abacavir/lamivudine or tenofovir/emtricitabine.

Results

The pharmacokinetics of dolutegravir were adequately described by a linear one compartment model with first order absorption, absorption lag time and first order elimination. Population estimates for apparent clearance, apparent volume of distribution, absorption rate constant and absorption lag time were 0.901 l h^–1, 17.4 l, 2.24 h⁻¹, and 0.263 h, respectively. Weight, smoking status, age and total bilirubin were predictors of clearance, weight was a predictor of volume of distribution and gender was a predictor of bioavailability. However, the magnitude of the effects of these covariates on steady-state dolutegravir plasma exposure was relatively small (<32%) and was not considered clinically significant. Race/ethnicity, HBV/HCV co-infection, CDC classification, albumin, creatinine clearance, alanine aminotransferase or aspartate aminotransferase did not influence the pharmacokinetics of dolutegravir in this analysis.

Conclusions

A population model that adequately characterizes dolutegravir pharmacokinetics has been developed. No dolutegravir dose adjustment by patient covariates is necessary in HIV-infected treatment-naive patients.