scholarly journals Conducting proportional meta-analysis in different types of systematic reviews: a guide for synthesisers of evidence

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Timothy Hugh Barker ◽  
Celina Borges Migliavaca ◽  
Cinara Stein ◽  
Verônica Colpani ◽  
Maicon Falavigna ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Meta Analysis ◽  
Worked Examples ◽  
Main Body ◽  
Single Group ◽  
Group Data ◽  
Different Types ◽  
Common Technique ◽  
Meta Analyses ◽  
Common Intervention

Abstract Background Single group data present unique challenges for synthesises of evidence. Proportional meta-analysis is becoming an increasingly common technique employed for the synthesis of single group data. Proportional meta-analysis shares many similarities with the conduct and reporting of comparative, or pairwise, meta-analysis. While robust and comprehensive methods exist detailing how researchers can conduct a meta-analysis that compares two (or more) groups against a common intervention, there is a scarcity of methodological guidance available to assist synthesisers of evidence in the conduct, interpretation, and importance of proportional meta-analysis in systematic reviews. Main body This paper presents an overview targeted to synthesisers of evidence and systematic review authors that details the methods, importance, and interpretation of a proportional meta-analysis. We provide worked examples of how proportional meta-analyses have been conducted in research syntheses previously and consider the methods, statistical considerations, and presentation of this technique. Conclusion This overview is designed to serve as practical guidance for synthesisers of evidence in the conduct of proportional meta-analyses.

scholarly journals How should systematic reviewers handle conference abstracts? A view from the trenches

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Roberta W. Scherer ◽  
Ian J. Saldanha
Keyword(s):  
Systematic Reviews ◽  
Treatment Effect ◽  
Meta Analysis ◽  
Good Practice ◽  
Effect Estimate ◽  
Main Body ◽  
Unpublished Studies ◽  
Study Results ◽  
Meta Analyses ◽  
Positive Results

Abstract Background While identifying and cataloging unpublished studies from conference proceedings is generally recognized as a good practice during systematic reviews, controversy remains whether to include study results that are reported in conference abstracts. Existing guidelines provide conflicting recommendations. Main body The main argument for including conference abstracts in systematic reviews is that abstracts with positive results are preferentially published, and published sooner, as full-length articles compared with other abstracts. Arguments against including conference abstracts are that (1) searching for abstracts is resource-intensive, (2) abstracts may not contain adequate information, and (3) the information in abstracts may not be dependable. However, studies comparing conference abstracts and fully published articles of the same study find only minor differences, usually with conference abstracts presenting preliminary results. Other studies that have examined differences in treatment estimates of meta-analyses with and without conference abstracts report changes in precision, but usually not in the treatment effect estimate. However, in some cases, including conference abstracts has made a difference in the estimate of the treatment effect, not just its precision. Instead of arbitrarily deciding to include or exclude conference abstracts in systematic reviews, we suggest that systematic reviewers should consider the availability of evidence informing the review. If available evidence is sparse or conflicting, it may be worthwhile to search for conference abstracts. Further, attempts to contact authors of abstracts or search for protocols or trial registers to supplement the information presented in conference abstracts is prudent. If unique information from conference abstracts is included in a meta-analysis, a sensitivity analysis with and without the unique results should be conducted. Conclusions Under given circumstances, it is worthwhile to search for and include results from conference abstracts in systematic reviews.

scholarly journals Good Statistical Practices for Contemporary Meta-Analysis: Examples Based on a Systematic Review on COVID-19 in Pregnancy

2021 ◽  
Vol 1 (2) ◽  
pp. 64-76
Author(s):  
Yuxi Zhao ◽  
Lifeng Lin
Keyword(s):  
Systematic Review ◽  
Systematic Reviews ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Worked Examples ◽  
Alternative Methods ◽  
Sufficient Information ◽  
Good Practices ◽  
Meta Analyses ◽  
In Pregnancy

Systematic reviews and meta-analyses have been increasingly used to pool research findings from multiple studies in medical sciences. The reliability of the synthesized evidence depends highly on the methodological quality of a systematic review and meta-analysis. In recent years, several tools have been developed to guide the reporting and evidence appraisal of systematic reviews and meta-analyses, and much statistical effort has been paid to improve their methodological quality. Nevertheless, many contemporary meta-analyses continue to employ conventional statistical methods, which may be suboptimal compared with several alternative methods available in the evidence synthesis literature. Based on a recent systematic review on COVID-19 in pregnancy, this article provides an overview of select good practices for performing meta-analyses from statistical perspectives. Specifically, we suggest meta-analysts (1) providing sufficient information of included studies, (2) providing information for reproducibility of meta-analyses, (3) using appropriate terminologies, (4) double-checking presented results, (5) considering alternative estimators of between-study variance, (6) considering alternative confidence intervals, (7) reporting prediction intervals, (8) assessing small-study effects whenever possible, and (9) considering one-stage methods. We use worked examples to illustrate these good practices. Relevant statistical code is also provided. The conventional and alternative methods could produce noticeably different point and interval estimates in some meta-analyses and thus affect their conclusions. In such cases, researchers should interpret the results from conventional methods with great caution and consider using alternative methods.

scholarly journals Systematic reviews and meta-analysis in nutrition research

2019 ◽  
Vol 122 (11) ◽  
pp. 1279-1294 ◽  
Author(s):  
George A. Kelley ◽  
Kristi S. Kelley
Keyword(s):  
Systematic Reviews ◽  
Meta Analysis ◽  
Technical Information ◽  
Major Elements ◽  
Future Research ◽  
High Quality ◽  
Nutrition Research ◽  
Production And Consumption ◽  
Different Types ◽  
Meta Analyses

AbstractThere exists an ever-increasing number of systematic reviews, with or without meta-analysis, in the field of nutrition. Concomitant with this increase is the increased use of such to guide future research as well as both practice and policy-based decisions. Given this increased production and consumption, a need exists to educate both producers and consumers of systematic reviews, with or without meta-analysis, on how to conduct and evaluate high-quality reviews of this nature in nutrition. The purpose of this paper is to try and address this gap. In the present manuscript, the different types of systematic reviews, with or without meta-analyses, are described as well as the description of the major elements, including methodology and interpretation, with a focus on nutrition. It is hoped that this non-technical information will be helpful to producers, reviewers and consumers of systematic reviews, with or without meta-analysis, in the field of nutrition.

scholarly journals Application of the Subspace-Based Methods in Health Monitoring of Civil Structures: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 10 (10) ◽  
pp. 3607
Author(s):  
Hoofar Shokravi ◽  
Hooman Shokravi ◽  
Norhisham Bakhary ◽  
Mahshid Heidarrezaei ◽  
Seyed Saeid Rahimian Koloor ◽  
...  
Keyword(s):  
System Identification ◽  
Systematic Reviews ◽  
Health Monitoring ◽  
Meta Analysis ◽  
Civil Structures ◽  
Literature Reviews ◽  
Research Gap ◽  
Meta Analyses ◽  
Subspace System Identification ◽  
Insight Into

A large number of research studies in structural health monitoring (SHM) have presented, extended, and used subspace system identification. However, there is a lack of research on systematic literature reviews and surveys of studies in this field. Therefore, the current study is undertaken to systematically review the literature published on the development and application of subspace system identification methods. In this regard, major databases in SHM, including Scopus, Google Scholar, and Web of Science, have been selected and preferred reporting items for systematic reviews and meta-analyses (PRISMA) has been applied to ensure complete and transparent reporting of systematic reviews. Along this line, the presented review addresses the available studies that employed subspace-based techniques in the vibration-based damage detection (VDD) of civil structures. The selected papers in this review were categorized into authors, publication year, name of journal, applied techniques, research objectives, research gap, proposed solutions and models, and findings. This study can assist practitioners and academicians for better condition assessment of structures and to gain insight into the literature.

scholarly journals A systematic review of pharmacist-led audit and feedback interventions to influence prescribing behaviour in general practice settings

2021 ◽  
Vol 29 (Supplement_1) ◽  
pp. i34-i35
Author(s):  
M Carter ◽  
N Abutheraa ◽  
N Ivers ◽  
J Grimshaw ◽  
S Chapman ◽  
...  
Keyword(s):  
General Practice ◽  
Systematic Reviews ◽  
Health Professionals ◽  
Meta Analysis ◽  
Cochrane Review ◽  
Audit And Feedback ◽  
Cochrane Library ◽  
Randomised Trials ◽  
Prescribing Behaviour ◽  
Meta Analyses

Abstract Introduction Audit and Feedback (A&F) involves measuring data about practice, comparing it with clinical guidelines, professional standards or peer performance, and then feeding back the data to individuals/groups of health professionals to encourage change in practice (if required). A 2012 Cochrane review (1) found A&F was effective in changing health professionals’ behaviour and suggested that the person who delivers the A&F intervention influences its effect. Increasingly, pharmacists work in general practice and often have responsibility for medication review and repeat prescriptions. The effectiveness of pharmacist-led A&F in influencing prescribing behaviour is uncertain. Aim This secondary analysis from an ongoing update of the original Cochrane review aims to identify and describe pharmacist-led A&F interventions and evaluate their impact on prescribing behaviour in general practice compared with no intervention. Methods This sub-review is registered with PROSPERO: CRD42020194355 and complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (2). For the updated Cochrane review, the Cochrane Effective Practice and Organization of Care Group searched MEDLINE (1946 to present), EMBASE, CINAHL and Cochrane Library (March 2019) to identify randomised trials featuring A&F interventions. For this sub-review, authors screened titles and abstracts (May 2020) to identify trials involving pharmacist-led A&F interventions in primary care, extracted data, and assessed risk of bias (RoB) in eligible studies. Review results are summarised descriptively. Heterogeneity will be assessed and a random-effects meta-analysis is planned. Publication bias for selected outcomes and the certainty of the body of evidence will be evaluated and presented. Sub-group analyses will be conducted. Results Titles and abstracts of 295 studies identified for inclusion in the Cochrane A&F review update were screened. Eleven studies (all cluster-randomised trials) conducted in 9 countries (Denmark, Italy, Netherlands, Norway, Republic of Ireland, UK, Australia, Malaysia, USA) were identified for inclusion (Figure 1). Six studies had low RoB, two had high risk due to dissimilarities between trial arms at baseline and/or insufficient detail about randomisation, and three studies had unclear RoB. Studies examined the effect of A&F on prescribing for specific conditions (e.g. hypertension), medications (e.g. antibiotics), populations (e.g. patients >70), and prescribing errors (e.g. inappropriate dose). The pharmacist delivering A&F was a colleague of intervention participants in five studies. Pharmacists’ levels of skill and experience varied; seven studies reported details of pharmacist training undertaken for trial purposes. A&F interventions in nine studies demonstrated changes in prescribing, including reductions in errors or inappropriate prescribing according to the study aims and smaller increases in unwanted prescribing compared with the control group. Data analyses are ongoing (results will be available for the conference). Conclusion The preliminary results demonstrate the effectiveness of pharmacist-led A&F interventions in different countries and health systems with influencing prescribing practice to align more closely with guidance. Studies measured different prescribing behaviours; meta-analysis is unlikely to include all 11 studies. Further detailed analysis including feedback format/content/frequency and pharmacist skill level/experience, work-base (external/internal to recipients), will examine the impact of specific features on intervention effectiveness. References 1. Ivers N, Jamtvedt G, Flottorp S, Young JM, Odgaard-Jensen J, French SD, et al. Audit and feedback: effects on professional practice and healthcare outcomes. Cochrane Database Syst Rev. 2012(6):CD000259. 2. Moher D, Liberati A, Tetzlaff J, Altman DG, Group P. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(7):e1000097.

scholarly journals A systematic review and meta-analysis protocol examining the clinical characteristics and epidemiological features of olfactory dysfunction (OD) in coronavirus disease 2019 (COVID-19)

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Rosemond Qian-Xiu Tan ◽  
Wai Tak Victor Li ◽  
Wing-Zi Shum ◽  
Sheung Chit Chu ◽  
Hang-Long Li ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Data ◽  
Systematic Reviews ◽  
Clinical Characteristics ◽  
Meta Analysis ◽  
Olfactory Dysfunction ◽  
Statistical Analyses ◽  
Human Populations ◽  
Meta Analyses ◽  
Analysis Protocol

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has caused recurring and major outbreaks in multiple human populations around the world. The plethora of clinical presentations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been described extensively, of which olfactory dysfunction (OD) was established as an important and common extrapulmonary manifestation of COVID-19 infection. The aim of this protocol is to conduct a systematic review and meta-analysis on peer-reviewed articles which described clinical data of OD in COVID-19 patients. Methods This research protocol has been prospectively registered with the Prospective Register of Systematic Reviews (PROSPERO; CRD42020196202). CINAHL, ClinicalTrials.gov, Cochrane Central, EMBASE, MEDLINE and PubMed, as well as Chinese medical databases China National Knowledge Infrastructure (CNKI), VIP and WANFANG, will be searched using keywords including ‘COVID-19’, ‘coronavirus disease’, ‘2019-nCoV’, ‘SARS-CoV-2’, ‘novel coronavirus’, ‘anosmia’, ‘hyposmia’, ‘loss of smell’, and ‘olfactory dysfunction’. Systematic review and meta-analysis will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines. Articles will be screened according to pre-specified inclusion and exclusion criteria to extract studies that include new clinical data investigating the effect of COVID-19 on olfactory dysfunction. Included articles will be reviewed in full; data including patient demographics, clinical characteristics of COVID-19-related OD, methods of olfactory assessment and relevant clinical outcomes will be extracted. Statistical analyses will be performed using the Comprehensive Meta-Analysis version 3. Discussion This systematic review and meta-analysis protocol will aim to collate and synthesise all available clinical evidence regarding COVID-19-related OD as an important neurosensory dysfunction of COVID-19 infection. A comprehensive search strategy and screening process will be conducted to incorporate broad clinical data for robust statistical analyses and representation. The outcome of the systematic review and meta-analysis will aim to improve our understanding of the symptomatology and clinical characteristics of COVID-19-related OD and identify knowledge gaps in its disease process, which will guide future research in this specific neurosensory defect. Systematic review registration PROSPERO registration number: CRD42020196202.

scholarly journals Efficacy and safety of instantaneous wave-free ratio in patients undergoing coronary revascularisation: protocol for a systematic review

BMJ Open ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. e017868
Author(s):  
Joey S.W. Kwong ◽  
Sheyu Li ◽  
Wan-Jie Gu ◽  
Hao Chen ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Systematic Review ◽  
Systematic Reviews ◽  
Meta Analysis ◽  
Adverse Outcomes ◽  
Coronary Revascularisation ◽  
Eligibility Criteria ◽  
Registration Number ◽  
Collection Form ◽  
Randomised Controlled ◽  
Meta Analyses

IntroductionEffective selection of coronary lesions for revascularisation is pivotal in the management of symptoms and adverse outcomes in patients with coronary artery disease. Recently, instantaneous ‘wave-free’ ratio (iFR) has been proposed as a new diagnostic index for assessing the severity of coronary stenoses without the need of pharmacological vasodilation. Evidence of the effectiveness of iFR-guided revascularisation is emerging and a systematic review is warranted.Methods and analysisThis is a protocol for a systematic review of randomised controlled trials and controlled observational studies. Electronic sources including MEDLINE via Ovid, Embase, Cochrane databases and ClinicalTrials.gov will be searched for potentially eligible studies investigating the effects of iFR-guided strategy in patients undergoing coronary revascularisation. Studies will be selected against transparent eligibility criteria and data will be extracted using a prestandardised data collection form by two independent authors. Risk of bias in included studies and overall quality of evidence will be assessed using validated methodological tools. Meta-analysis will be performed using the Review Manager software. Our systematic review will be performed according to the guidance from the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.Ethics and disseminationEthics approval is not required. Results of the systematic review will be disseminated as conference proceedings and peer-reviewed journal publication.Trial registration numberThis protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42017065460.

Sinus Radiological Findings in General Asymptomatic Populations: A Systematic Review of Incidental Mucosal Changes

2021 ◽  
pp. 019459982110350
Author(s):  
Basil Razi ◽  
Adam Perkovic ◽  
Raquel Alvarado ◽  
Anna Stroud ◽  
Jacqueline Ho ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Meta Analysis ◽  
Population Groups ◽  
Bibliographic Search ◽  
Comprehensive Search ◽  
Mucosal Changes ◽  
Meta Analyses ◽  
Asymptomatic Subjects ◽  
Mucosal Thickening ◽  
Retention Cysts

Objective To determine the range of incidental mucosal changes in a general sinonasally asymptomatic population on radiology. Data Sources Medline (1996-present) and Embase (1974-present) were searched on March 14, 2020, to identify articles that reported radiological sinus mucosal findings in asymptomatic population groups. Bibliographic search of included studies was conducted to identify additional articles. Review Methods The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Cochrane Handbook for Systematic Reviews of Interventions. A comprehensive search strategy was formulated and articles screened to extract data reporting Lund-Mackay (LM) score, presence of mucous retention cysts, and maxillary mucosal thickening. A random-effects model was used in meta-analysis. Results A total of 950 articles were identified, of which 33 manuscripts met the inclusion criteria. The included studies involved 16,966 sinonasally asymptomatic subjects. The mean LM score was 2.24 (95% CI, 1.61-2.87), and an LM score of ≥4 in 14.71% (95% CI, 6.86-24.82%) was present across all general asymptomatic population groups. Mucous retention cysts were noted in 13% (95% CI, 8.33-18.55%) and maxillary mucosal thickening of ≥2 mm in 17.73% (95% CI, 8.67-29.08%). Conclusion The prevalence of incidental mucosal changes in a general asymptomatic population on radiology needs to be considered when making a diagnosis of chronic rhinosinusitis.

scholarly journals A Statistical Method for Synthesizing Meta-Analyses

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Liansheng Larry Tang ◽  
Michael Caudy ◽  
Faye Taxman
Keyword(s):  
Statistical Method ◽  
Effect Size ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Weighted Mean ◽  
Summary Effect ◽  
Different Types ◽  
Meta Analyses ◽  
Size Estimates ◽  
Similar Search

Multiple meta-analyses may use similar search criteria and focus on the same topic of interest, but they may yield different or sometimes discordant results. The lack of statistical methods for synthesizing these findings makes it challenging to properly interpret the results from multiple meta-analyses, especially when their results are conflicting. In this paper, we first introduce a method to synthesize the meta-analytic results when multiple meta-analyses use the same type of summary effect estimates. When meta-analyses use different types of effect sizes, the meta-analysis results cannot be directly combined. We propose a two-step frequentist procedure to first convert the effect size estimates to the same metric and then summarize them with a weighted mean estimate. Our proposed method offers several advantages over existing methods by Hemming et al. (2012). First, different types of summary effect sizes are considered. Second, our method provides the same overall effect size as conducting a meta-analysis on all individual studies from multiple meta-analyses. We illustrate the application of the proposed methods in two examples and discuss their implications for the field of meta-analysis.

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