Systematic review and meta-analysis of the genetics of peripheral arterial disease

Background

Peripheral artery disease (PAD) impacts more than 200 million people worldwide. The understanding of the genetics of the disease and its clinical implications continue to evolve. This systematic review provides a comprehensive summary of all DNA variants that have been studied in association with the diagnosis and progression of PAD, with a meta-analysis of the ones replicated in the literature.

Methods

A systematic review of all studies examining DNA variants associated with the diagnosis and progression of PAD was performed. Candidate gene and genome-wide association studies (GWAS) were included. A meta-analysis of 13 variants derived from earlier smaller candidate gene studies of the diagnosis of PAD was performed. The literature on the progression of PAD was limited, and a meta-analysis was not feasible because of the heterogeneity in the criteria used to characterize it.

Results

A total of 231 DNA variants in 112 papers were studied for the association with the diagnosis of PAD. There were significant variations in the definition of PAD and the selection of controls in the various studies. GWAS have established 19 variants associated with the diagnosis of PAD that were replicated in several large patient cohorts. Only variants in intercellular adhesion molecule-1 (rs5498), IL-6 (rs1800795), and hepatic lipase (rs2070895) showed significant association with the diagnosis of PAD. However, these variants were not noted in the published GWAS.

Conclusions

Genetic research in the diagnosis of PAD has significant heterogeneity, but recent GWAS have demonstrated variants consistently associated with the disease. More research focusing on the progression of PAD is needed to identify patients at risk of adverse events and develop strategies that would improve their outcomes.

Long-term natural history of visual acuity in eyes with choroideremia: a systematic review and meta-analysis of data from 1004 individual eyes

BACKGROUND/AIMS

Best-corrected visual acuity (BCVA) is the most common primary endpoint in treatment trials for choroideremia (CHM) but the long-term natural history of BCVA is unclear.

METHODS

We searched in seven databases to identify studies that reported BCVA of untreated eyes with CHM. We sought individual-level data and performed segmented regression between BCVA and age. For eyes followed longitudinally, we introduced a horizontal translation factor to each dataset to account for different ages at onset of a rapid BCVA decline.

RESULTS

We included 1004 eyes from 23 studies. BCVA of the right and left eyes was moderately correlated (r=0.60). BCVA as a function of age followed a 2-phase decline (slow followed by rapid decline), with an estimated transition age of 39.1 years (95% CI 33.5 to 44.7). After the introduction of horizontal translation factors to longitudinal datasets, BCVA followed a 2-phase decline until it reached 0 letters (r²=0.90). The BCVA decline rate was 0.33 letters/year (95% CI -0.38 to 1.05) before 39 years, and 1.23 letters/year (95% CI 0.55 to 1.92) after 39 years (p=0.004).

CONCLUSION

BCVA in eyes with CHM follows a 2-phase linear decline with a transition age of approximately 39 years. Future trials enrolling young patients may not be able to use BCVA as a primary or sole endpoint, but rather, may need to employ additional disease biomarkers that change before age 39. BCVA may still have utility as a primary endpoint for patients older than 39 years who have measurable BCVA decline rates.

Long-term Natural History of Atrophy in Eyes with Choroideremia-A Systematic Review and Meta-analysis of Individual-Level Data

PURPOSE

To conduct a systematic review and meta-analysis of the natural history of atrophy secondary to choroideremia (CHM).

CLINICAL RELEVANCE

A sensitive and reliable anatomic measure to monitor disease progression is needed in treatment trials for CHM. However, the long-term natural history of the residual retinal pigment epithelium (RPE) is unclear, with reported RPE area decline rates varying widely among patients.

METHODS

We searched in 7 literature databases up through July 17, 2019, to identify studies that assessed the residual RPE area in untreated eyes with CHM using fundus autofluorescence (FAF). We sought individual-eye data and investigated the RPE decline pattern using 3 models: the area linear model (ALM), radius linear model (RLM), and area exponential model (AEM), in which the area, radius, and log-transformed area of RPE change linearly with time, respectively. To account for different eyes' entry times into the studies, we added a horizontal translation factor to each dataset. The RPE decline rate was estimated using a 2-stage random-effects meta-analysis. We assessed the risk of bias using the Quality In Prognosis Studies tool.

RESULTS

Of 807 articles screened, we included 9 articles containing cross-sectional data (257 eyes) from 6 studies and longitudinal data (229 visits from 68 eyes) from 5 studies. The residual RPE area followed a trend of exponential decay as a function of patient age. After the introduction of horizontal translation factors to longitudinal datasets of individual eyes, the datasets fit along a straight line in the AEM over nearly 60 years (r² = 0.997). The decline rate of log-transformed RPE area was 0.050 (95% confidence interval, 0.046-0.055) log(mm²)/year and was independent of the baseline RPE area (r = -0.18; P = 0.15) and age (r = 0.06; P = 0.63). In contrast, the decline rates of the area and effective radius of residual RPE strongly correlated with the baseline RPE area (r = 0.90 and 0.61, respectively; P < 0.001).

CONCLUSIONS

The loss of residual RPE area in untreated eyes with CHM follows the AEM over approximately 60 years. Log-transformed residual RPE area measured by FAF can serve as an anatomic endpoint to monitor CHM.

Topographic Variation of the Growth Rate of Geographic Atrophy in Nonexudative Age-Related Macular Degeneration: A Systematic Review and Meta-analysis

Purpose

To determine the impact of topographic locations on the progression rate of geographic atrophy (GA).

Methods

We searched in five literature databases up to May 3, 2019, for studies that evaluated the growth rates of GA lesions at different retinal regions. We performed random-effects meta-analyses to determine and compare the GA effective radius growth rates in four location groups defined by two separate classification schemes: (1) macular center point involved (CPI) or spared (CPS) in classification 1, and (2) foveal zone involved (FZI) or spared (FZS) in classification 2. We then estimated the GA growth rate in eight topographic zones and used the data to model the GA expansion.

Results

We included 11 studies with 3254 unique eyes. In studies that used classification 1, the effective radius growth rate was 30.1% higher in the CPS group (0.203 ± 0.013 mm/year) than in the CPI group (0.156 ± 0.011 mm/year) (P < 0.001). This trend became significantly more prominent in classification 2, where the growth rate was 61.7% higher in the FZS group (0.215 ± 0.012 mm/year) than in the FZI group (0.133 ± 0.009 mm/year) (P < 0.001). The estimated GA effective radius growth rates in eight retinal zones fit a Gaussian function, and the modeling of GA expansion gave rise to various GA configurations comparable to clinical observations.

Conclusions

This study indicates that the GA progression rate varies significantly across different retinal locations. Our analysis may shed light on the natural history and underlying mechanism of GA progression.

Updating insights into rosiglitazone and cardiovascular risk through shared data: individual patient and summary level meta-analyses

OBJECTIVES

To conduct a systematic review and meta-analysis of the effects of rosiglitazone treatment on cardiovascular risk and mortality using multiple data sources and varying analytical approaches with three aims in mind: to clarify uncertainties about the cardiovascular risk of rosiglitazone; to determine whether different analytical approaches are likely to alter the conclusions of adverse event meta-analyses; and to inform efforts to promote clinical trial transparency and data sharing.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

DATA SOURCES

GlaxoSmithKline's (GSK's) ClinicalStudyDataRequest.com for individual patient level data (IPD) and GSK's Study Register platforms, MEDLINE, PubMed, Embase, Web of Science, Cochrane Central Registry of Controlled Trials, Scopus, and ClinicalTrials.gov from inception to January 2019 for summary level data.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomized, controlled, phase II-IV clinical trials that compared rosiglitazone with any control for at least 24 weeks in adults.

DATA EXTRACTION AND SYNTHESIS

For analyses of trials for which IPD were available, a composite outcome of acute myocardial infarction, heart failure, cardiovascular related death, and non-cardiovascular related death was examined. These four events were examined independently as secondary analyses. For analyses including trials for which IPD were not available, myocardial infarction and cardiovascular related death were examined, which were determined from summary level data. Multiple meta-analyses were conducted that accounted for trials with zero events in one or both arms with two different continuity corrections (0.5 constant and treatment arm) to calculate odds ratios and risk ratios with 95% confidence intervals.

RESULTS

33 eligible trials were identified from ClinicalStudyDataRequest.com for which IPD were available (21 156 patients). Additionally, 103 trials for which IPD were not available were included in the meta-analyses for myocardial infarction (23 683 patients), and 103 trials for which IPD were not available contributed to the meta-analyses for cardiovascular related death (22 772 patients). Among 29 trials for which IPD were available and that were included in previous meta-analyses using GSK's summary level data, more myocardial infarction events were identified by using IPD instead of summary level data for 26 trials, and fewer cardiovascular related deaths for five trials. When analyses were limited to trials for which IPD were available, and a constant continuity correction of 0.5 and a random effects model were used to account for trials with zero events in only one arm, patients treated with rosiglitazone had a 33% increased risk of a composite event compared with controls (odds ratio 1.33, 95% confidence interval 1.09 to 1.61; rosiglitazone population: 274 events among 11 837 patients; control population: 219 events among 9319 patients). The odds ratios for myocardial infarction, heart failure, cardiovascular related death, and non-cardiovascular related death were 1.17 (0.92 to 1.51), 1.54 (1.14 to 2.09), 1.15 (0.55 to 2.41), and 1.18 (0.60 to 2.30), respectively. For analyses including trials for which IPD were not available, odds ratios for myocardial infarction and cardiovascular related death were attenuated (1.09, 0.88 to 1.35, and 1.12, 0.72 to 1.74, respectively). Results were broadly consistent when analyses were repeated using trials with zero events across both arms and either of the two continuity corrections was used.

CONCLUSIONS

The results suggest that rosiglitazone is associated with an increased cardiovascular risk, especially for heart failure events. Although increased risk of myocardial infarction was observed across analyses, the strength of the evidence varied and effect estimates were attenuated when summary level data were used in addition to IPD. Because more myocardial infarctions and fewer cardiovascular related deaths were reported in the IPD than in the summary level data, sharing IPD might be necessary when performing meta-analyses focused on safety.

SYSTEMATIC REVIEW REGISTRATION

OSF Home https://osf.io/4yvp2/.

Librarians as methodological peer reviewers for systematic reviews: results of an online survey

BACKGROUND

Developing a comprehensive, reproducible literature search is the basis for a high-quality systematic review (SR). Librarians and information professionals, as expert searchers, can improve the quality of systematic review searches, methodology, and reporting. Likewise, journal editors and authors often seek to improve the quality of published SRs and other evidence syntheses through peer review. Health sciences librarians contribute to systematic review production but little is known about their involvement in peer reviewing SR manuscripts.

METHODS

This survey aimed to assess how frequently librarians are asked to peer review systematic review manuscripts and to determine characteristics associated with those invited to review. The survey was distributed to a purposive sample through three health sciences information professional listservs.

RESULTS

There were 291 complete survey responses. Results indicated that 22% (n = 63) of respondents had been asked by journal editors to peer review systematic review or meta-analysis manuscripts. Of the 78% (n = 228) of respondents who had not already been asked, 54% (n = 122) would peer review, and 41% (n = 93) might peer review. Only 4% (n = 9) would not review a manuscript. Respondents had peer reviewed manuscripts for 38 unique journals and believed they were asked because of their professional expertise. Of respondents who had declined to peer review (32%, n = 20), the most common explanation was "not enough time" (60%, n = 12) followed by "lack of expertise" (50%, n = 10).The vast majority of respondents (95%, n = 40) had "rejected or recommended a revision of a manuscript| after peer review. They based their decision on the "search methodology" (57%, n = 36), "search write-up" (46%, n = 29), or "entire article" (54%, n = 34). Those who selected "other" (37%, n = 23) listed a variety of reasons for rejection, including problems or errors in the PRISMA flow diagram; tables of included, excluded, and ongoing studies; data extraction; reporting; and pooling methods.

CONCLUSIONS

Despite being experts in conducting literature searches and supporting SR teams through the review process, few librarians have been asked to review SR manuscripts, or even just search strategies; yet many are willing to provide this service. Editors should involve experienced librarians with peer review and we suggest some strategies to consider.

Natural History of Autosomal Recessive Stargardt Disease in Untreated Eyes: A Systematic Review and Meta-analysis of Study- and Individual-Level Data

TOPIC

Systematic review and meta-analysis of the natural history of autosomal recessive Stargardt disease (STGD1).

CLINICAL RELEVANCE

Controversy exists regarding the progression pattern of atrophic lesions secondary to STGD1, and the reported growth rates vary widely among studies.

METHODS

We searched in 6 literature databases up through March 15, 2019, to identify studies that monitored atrophy progression by fundus autofluorescence in untreated eyes with STGD1 for 6 months or more. We analyzed both study- and individual-level data from the included studies using 3 models: the area linear model (ALM), radius linear model (RLM), and area exponential model (AEM), in which the area, radius, and natural log-transformed area changes linearly with time, respectively. A horizontal translation factor was added to each dataset to correct for different participants' entry times into the studies. The best model was determined by the predicted age of lesion onset and dependence of growth rates on baseline lesion sizes. The risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

Of 3158 articles screened, 7 studies (564 eyes) met our inclusion criteria. Cumulative study- and individual-level datasets fit along a straight line in the RLM after introducing horizontal translation factors to correct for different entry times (r² = 0.99 and r² = 0.93, respectively). The growth rate of effective lesion radius was 0.104 mm/year (95% confidence interval, 0.086-0.123 mm/year). The age of atrophy onset predicted by the RLM (22.7±5.0 years) was comparable to the reported age at onset of symptoms (22.1±3.1 years); in contrast, the predictions by the ALM and AEM deviated from this number by more than 5 years. Based on the individual-level data, the effective radius growth rate was independent of the baseline lesion size (r = 0.06); in comparison, the growth rates of area and natural log-transformed area were significantly dependent on the baseline lesion size (r = 0.47 and r = -0.33, respectively).

CONCLUSIONS

The progression of STGD1 lesions followed the RLM in both study- and individual-level data. The effective radius growth rate of atrophic lesions could serve as a reliable outcome measure to monitor STGD1 progression.

Fellow Eye Status Is a Biomarker for the Progression Rate of Geographic Atrophy: A Systematic Review and Meta-analysis

TOPIC

Systematic review and meta-analysis of how fellow eye status predicts the progression rate of geographic atrophy (GA).

CLINICAL RELEVANCE

The status of age-related macular degeneration (AMD) in the fellow eye has been used as an indicator of the GA progression rates in primary eyes, but the reported growth rates vary widely in prior clinical studies.

METHODS

We searched MEDLINE, EMBASE, Cochrane Library, Clinicaltrials.gov, and PubMed up to September 12, 2018, for studies that classified treatment-naive GA patients based on different AMD manifestations in the fellow eyes and that monitored GA progression in the primary eyes. Three fellow eye statuses were analyzed: (1) no GA or choroidal neovascularization (CNV) in the fellow eye, (2) GA in the fellow eye, and (3) CNV in the fellow eye. To account for the patients' different entry times, we introduced a horizontal translation factor to shift each dataset within each group. We determined the translation factor by adjusting it 1 month at a time until the r² in weighted least squares regression (r²_WLS) was maximized for the cumulative linear trend line of all datasets. Heterogeneity and study quality were assessed using the I² statistic and Newcastle-Ottawa scale, respectively. Publication bias was evaluated by funnel plots, the Egger test, and the Begg test.

RESULTS

We included 9 studies with 2134 eyes from 1835 patients. After the introduction of translation factors, the datasets in each fellow eye group fit along a straight line with a high r²_WLS. The GA radius growth rate in fellow eyes with GA (0.179±0.003 mm/year) and fellow eyes with CNV (0.159±0.015 mm/year) was significantly higher than that in fellow eyes without GA or CNV (0.110±0.009 mm/year; P < 0.001 and P = 0.02, respectively). We found no significant difference in the GA radius growth rates between fellow eyes with GA and fellow eyes with CNV (P = 0.42).

CONCLUSIONS

We confirmed that the presence of advanced AMD in the fellow eye, defined as GA or CNV, can serve as a biomarker of the GA enlargement rate in the primary eye. This may assist the design of clinical trials and may shed light on the natural history of GA expansion.

Quality Assurance Practices in Obstetric Care: A Survey of Hospitals in California

OBJECTIVE

To assess hospital practices in obstetric quality management activities and identify institutional characteristics associated with utilization of evidence-supported practices.

METHODS

Data for this study came from a statewide survey of obstetric hospitals in California regarding their organization and delivery of perinatal care. We analyzed responses from 185 hospitals that completed quality assurance sections of the survey to assess their practices in a broad spectrum of quality enhancement activities. The association between institutional characteristics and adoption of evidence-supported practices (ie, those supported by prior literature or recommended by professional organizations as beneficial for improving birth outcome or patient safety) was examined using bivariate analysis and appropriate statistical tests.

RESULTS

Most hospitals regularly audited adherence to written protocols regarding critical areas of care; however, 77.7% and 16.8% reported not having written guidelines on diagnosis of labor arrest and management of abnormal fetal heart rate, respectively. Private nonprofit hospitals were more likely to have a written protocol for management of abnormal fetal heart rate (P=.002). One in 10 hospitals (9.7%) did not regularly review cases with significant morbidity or mortality, and only 69.0% regularly tracked indications for cesarean delivery. Moreover, 26.3%, 14.3%, and 8.7% of the hospitals reported never performing interprofessional simulations for eclampsia, shoulder dystocia, or postpartum hemorrhage, respectively. Teaching status was associated with more frequent simulations in these three areas (P≤.04 for all), while larger volume was associated with more frequent simulations for eclampsia (P=.04).

CONCLUSION

Hospitals in California engage in a wide range of practices to assure or improve quality of obstetric care, but substantial variation in practice exists among hospitals. There is opportunity for improvement in adoption of evidence-supported practices.

Growth and Rupture Risk of Small Unruptured Intracranial Aneurysms: A Systematic Review

BACKGROUND

Small unruptured intracranial aneurysms (UIAs) are increasingly diagnosed. Management depends on growth and rupture risks, which may vary by aneurysm size.

PURPOSE

To summarize evidence about the growth and rupture risk of UIAs 7 mm and smaller and to explore differences in growth and rupture risks of very small (≤3 mm) and small (≤5 mm) aneurysms.

DATA SOURCES

MEDLINE, EMBASE, Scopus, and the Cochrane Library from inception to 2017 (with no language restrictions).

STUDY SELECTION

Published case series and observational studies that reported natural history data on UIAs 7 mm and smaller.

DATA EXTRACTION

2 reviewers abstracted study information, evaluated study quality, and graded strength of evidence.

DATA SYNTHESIS

Of 26 studies, 5, 10, and 8 described the growth rate of aneurysms 3 mm and smaller, 5 mm and smaller, and 7 mm and smaller, respectively, whereas rupture rates were reported in 7, 11, and 13 studies for aneurysms 3 mm and smaller, 5 mm and smaller, and 7 mm and smaller, respectively. The annualized growth rate was less than 3% in all but 1 study for all 3 size categories. The annualized rupture rate was 0%, less than 0.5%, and less than 1% for the 3 size categories, respectively. Strength of evidence was very low quality for growth rates and low quality for rupture rates.

LIMITATION

Heterogeneous definitions of growth; heterogeneous and selective treatment and follow-up methods, particularly in high-risk patients.

CONCLUSION

Poor-quality evidence suggests that small UIAs have low growth and rupture rates and very small UIAs have little or no risk for rupture.

PRIMARY FUNDING SOURCE

None.

Systematic Review of Community-Engaged Research in Ophthalmology

Introduction

Community-engaged research (CEnR) allows researchers and community organizations to partner together to improve health outcomes and to decrease health disparities. While prevalent in other fields of medicine, it is rarely used in ophthalmology.

Areas covered

A comprehensive search of Ovid MEDLINE, NLM Pubmed, Ovid Embase, Scopus and the Cochrane Library for the Medical Subject Headings (MeSH) "Community-based participatory research" and text word variations including participatory research, community engagement, community research, partnered research, community-institutional relations, CENR, CBPR in addition to variations on ophthalmology, eye diseases, vision disorders and eye injuries yielded 451 unique references. Two ophthalmologists (KN, PANC) reviewed the titles and abstracts and identified 37 relevant studies. Expert consultation yielded an additional reference. After reviewing the full texts and excluding non-English texts, 18 articles met the necessary criteria. The eighteen articles all utilized at least one of the nine principles of CEnR.

Expert commentary

Ophthalmology is perfectly positioned to benefit from CEnR. Increased community engagement in ophthalmic research would expand the reach of our work and address some of the most difficult problems in vision disparities and outcomes.

Utility of MRI for cervical spine clearance after blunt traumatic injury: a meta-analysis

OBJECTIVES

To quantify the rate of unstable injuries detected by MRI missed on CT in blunt cervical spine (CS) trauma patients and assess the utility of MRI in CS clearance.

METHODS

We undertook a systematic review of worldwide evidence across five major medical databases and performed a meta-analysis. Studies were included if they reported the number of unstable injuries or gave enough details for inference. Variables assessed included severity, CT/MRI specifications, imaging timing, and outcome/follow-up. Pooled incidences of unstable injury on follow-up weighted by inverse-of-variance among all included and obtunded or alert patients were reported.

RESULTS

Of 428 unique citations, 23 proved eligible, with 5,286 patients found, and 16 unstable injuries reported in five studies. The overall pooled incidence is 0.0029 %. Among studies reporting only obtunded patients, the pooled incidence is 0.017 %. In alert patients, the incidence is 0.011 %. All reported positive findings were critically reviewed, and only 11 could be considered truly unstable.

CONCLUSIONS

There is significant heterogeneity in the literature regarding the use of imaging after a negative CT. The finding rate on MRI for unstable injury is extremely low in obtunded and alert patients. Although MRI is frequently performed, its utility and cost-effectiveness needs further study.

KEY POINTS

• There were 16 unstable injuries on follow-up MRI among 5286 patients. • The positive finding rate among obtunded patients was 0.12 %. • The positive finding rate among alert, awake patients was 0.72 %. • MRI has a high false-positive rate; its utility mandates further studies. • The use and role of "confirmatory" tests shows wide variations.

Micro-costing studies in the health and medical literature: protocol for a systematic review

BACKGROUND

Micro-costing is a cost estimation method that allows for precise assessment of the economic costs of health interventions. It has been demonstrated to be particularly useful for estimating the costs of new interventions, for interventions with large variability across providers, and for estimating the true costs to the health system and to society. However, existing guidelines for economic evaluations do not provide sufficient detail of the methods and techniques to use when conducting micro-costing analyses. Therefore, the purpose of this study is to review the current literature on micro-costing studies of health and medical interventions, strategies, and programs to assess the variation in micro-costing methodology and the quality of existing studies. This will inform current practice in conducting and reporting micro-costing studies and lead to greater standardization in methodology in the future.

METHODS/DESIGN

We will perform a systematic review of the current literature on micro-costing studies of health and medical interventions, strategies, and programs. Using rigorously designed search strategies, we will search Ovid MEDLINE, EconLit, BIOSIS Previews, Embase, Scopus, and the National Health Service Economic Evaluation Database (NHS EED) to identify relevant English-language articles. These searches will be supplemented by a review of the references of relevant articles identified. Two members of the review team will independently extract detailed information on the design and characteristics of each included article using a standardized data collection form. A third reviewer will be consulted to resolve discrepancies. We will use checklists that have been developed for critical appraisal of health economics studies to evaluate the quality and potential risk of bias of included studies.

DISCUSSION

This systematic review will provide useful information to help standardize the methods and techniques for conducting and reporting micro-costing studies in research, which can improve the quality and transparency of future studies and enhance comparability and interpretation of findings. In the long run, these efforts will facilitate clinical and health policy decision-making about resource allocation.

TRIAL REGISTRATION

Systematic review registration: PROSPERO CRD42014007453.