scholarly journals Real-world Performance of Meta-analysis Methods for Double-Zero-Event Studies with Dichotomous Outcomes Using the Cochrane Database of Systematic Reviews

2019 ◽  
Vol 34 (6) ◽  
pp. 960-968 ◽  
Author(s):  
Yanan Ren ◽  
Lifeng Lin ◽  
Qinshu Lian ◽  
Hui Zou ◽  
Haitao Chu
Keyword(s):  
Systematic Reviews ◽  
Real World ◽  
Meta Analysis ◽  
Event Studies ◽  
Double Zero ◽  
Analysis Methods ◽  
Cochrane Database ◽  
Dichotomous Outcomes ◽  
Zero Event

scholarly journals Impact of including or excluding both-armed zero-event studies on using standard meta-analysis methods for rare event outcome: a simulation study

BMJ Open ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. e010983 ◽  
Author(s):  
Ji Cheng ◽  
Eleanor Pullenayegum ◽  
John K Marshall ◽  
Alfonso Iorio ◽  
Lehana Thabane
Keyword(s):  
Simulation Study ◽  
Meta Analysis ◽  
Rare Event ◽  
Event Studies ◽  
Analysis Methods ◽  
Zero Event

scholarly journals Double-zero-event studies matter: a re-evaluation of physical distancing, face masks, and eye protection for preventing person-to-person transmission of COVID-19 and its policy impact

2020 ◽  
Author(s):  
Mengli Xiao ◽  
Lifeng Lin ◽  
James S. Hodges ◽  
Chang Xu ◽  
Haitao Chu
Keyword(s):  
Linear Mixed Model ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Event Studies ◽  
Sensitivity Analyses ◽  
Prevention Measures ◽  
Double Zero ◽  
Eye Protection ◽  
Meta Analyses ◽  
Zero Event

Objectives: High-quality meta-analyses on COVID-19 are in urgent demand for evidence-based decision making. However, conventional approaches exclude double-zero-event studies (DZS) from meta-analyses. We assessed whether including such studies impacts the conclusions in a recent systematic urgent review on prevention measures for preventing person-to-person transmission of COVID-19. Study designs and settings: We extracted data for meta-analyses containing DZS from a recent review that assessed the effects of physical distancing, face masks, and eye protection for preventing person-to-person transmission. A bivariate generalized linear mixed model was used to re-do the meta-analyses with DZS included. We compared the synthesized relative risks (RRs) of the three prevention measures, their 95% confidence intervals (CI), and significance tests (at the level of 0.05) including and excluding DZS. Results: The re-analyzed COVID-19 data containing DZS involved a total of 1,784 participants who were not considered in the original review. Including DZS noticeably changed the synthesized RRs and 95% CIs of several interventions. For the meta-analysis of the effect of physical distancing, the RR of COVID-19 decreased from 0.15 (95% CI, 0.03 to 0.73) to 0.07 (95% CI, 0.01 to 0.98). For several meta-analyses, the statistical significance of the synthesized RR was changed. The RR of eye protection with a physical distance of 2 m and the RR of physical distancing when using N95 respirators were no longer statistically significant after including DZS. Conclusions: DZS may contain useful information. Sensitivity analyses that include DZS in meta-analysis are recommended.

scholarly journals Meta-analysis with zero-event studies: a comparative study with application to COVID-19 data

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jia-Jin Wei ◽  
En-Xuan Lin ◽  
Jian-Dong Shi ◽  
Ke Yang ◽  
Zong-Liang Hu ◽  
...  
Keyword(s):  
Relative Risk ◽  
Comparative Study ◽  
Effect Size ◽  
Linear Mixed Model ◽  
Meta Analysis ◽  
Event Studies ◽  
New Method ◽  
Double Zero ◽  
Continuity Correction ◽  
Zero Event

Abstract Background Meta-analysis is a statistical method to synthesize evidence from a number of independent studies, including those from clinical studies with binary outcomes. In practice, when there are zero events in one or both groups, it may cause statistical problems in the subsequent analysis. Methods In this paper, by considering the relative risk as the effect size, we conduct a comparative study that consists of four continuity correction methods and another state-of-the-art method without the continuity correction, namely the generalized linear mixed models (GLMMs). To further advance the literature, we also introduce a new method of the continuity correction for estimating the relative risk. Results From the simulation studies, the new method performs well in terms of mean squared error when there are few studies. In contrast, the generalized linear mixed model performs the best when the number of studies is large. In addition, by reanalyzing recent coronavirus disease 2019 (COVID-19) data, it is evident that the double-zero-event studies impact the estimate of the mean effect size. Conclusions We recommend the new method to handle the zero-event studies when there are few studies in a meta-analysis, or instead use the GLMM when the number of studies is large. The double-zero-event studies may be informative, and so we suggest not excluding them.

scholarly journals Meta-analysis With Zero-event Studies: A Comparative Study With Application to COVID-19 Data

2021 ◽  
Author(s):  
Jiajin Wei ◽  
Enxuan Lin ◽  
Jiandong Shi ◽  
Ke Yang ◽  
Zongliang Hu ◽  
...  
Keyword(s):  
Relative Risk ◽  
Comparative Study ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Meta Analysis ◽  
Event Studies ◽  
New Method ◽  
Double Zero ◽  
Continuity Correction ◽  
Zero Event

Abstract Background: Meta-analysis is a statistical method to synthesize evidence from a number of independent studies, including those from clinical studies with binary outcomes. In practice, when there are zero events in one or both groups, it may cause statistical problems in the subsequent analysis. Methods: In this paper, by considering the relative risk as the effect size, we conduct a comparative study that consists of four continuity correction methods and another state-of-the-art method without the continuity correction, namely the generalized linear mixed models. To further advance the literature, we also introduce a new method of the continuity correction for estimating the relative risk. Results: From the simulation studies, the new method performs well in terms of mean squared error when there are few studies. In contrast, the generalized linear mixed model performs the best when the number of studies is large. In addition, by reanalyzing a recent COVID-19 data, it is evident that the double-zero-event studies impact on the estimate of the mean effect size.Conclusion: We recommend the new method to handle the zero-event studies when there are only few studies in the meta-analysis, or instead use the GLMM when the number of studies is large. The double-zero-event study may beinformative, and so we suggest not excluding them.

scholarly journals Epidemiology of Cancers in Men Who Have Sex with Men (MSM): A Protocol for Umbrella Review of Systematic Reviews

2020 ◽  
Vol 17 (14) ◽  
pp. 4954
Author(s):  
Manoj Kumar Honaryar ◽  
Yelena Tarasenko ◽  
Maribel Almonte ◽  
Vitaly Smelov
Keyword(s):  
Sexual Orientation ◽  
Systematic Reviews ◽  
Data Extraction ◽  
Meta Analysis ◽  
Umbrella Review ◽  
Team Members ◽  
Cochrane Database ◽  
Health Community ◽  
Global Epidemiology ◽  
Sex With Men

While earlier studies on men having sex with men (MSM) tended to examine infection-related cancers, an increasing number of studies have been focusing on effects of sexual orientation on other cancers and social and cultural causes for cancer disparities. As a type of tertiary research, this umbrella review (UR) aims to synthesize findings from existing review studies on the effects of sexual orientation on cancer. Relevant peer-reviewed systematic reviews (SRs) will be identified without date or language restrictions using MEDLINE, Cochrane Database of Systematic Reviews, and the International Prospective Register for Systematic Reviews, among others. The research team members will prepare the data extraction forms. Two reviewers will independently assess extracted SRs using the Assessment of Methodological Quality of Systematic Reviews. A third reviewer will weigh in to resolve discrepancies. The reviewers will be blinded to publisher, journal, and authors, making their judgements on the title, year, and abstract. The Preferred Reporting Items for Systematic Reviews and Meta-analysis checklist will guide data synthesis. By collating evidence from multiple reviews into one accessible and usable document, our first UR on global epidemiology of malignancies among MSM would serve as an evidence-based decision-making tool for the public health community.

scholarly journals Systematic Reviews and Meta-Analysis in Spine Surgery—How Good Are They in Methodological Quality? A Systematic Review

2020 ◽  
pp. 219256822090681 ◽  
Author(s):  
Muthu Sathish ◽  
Ramakrishnan Eswar
Keyword(s):  
Systematic Review ◽  
Spine Surgery ◽  
Systematic Reviews ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Eligibility Criteria ◽  
Cochrane Database ◽  
Critical Flaw ◽  
Meta Analyses

Study Design: Systematic review. Objectives: To assess the methodological quality of systematic reviews and meta-analyses in spine surgery over the past 2 decades. Materials and Methods: We conducted independent and in duplicate systematic review of the published systematic reviews and meta-analyses between 2000 and 2019 from PubMed Central and Cochrane Database pertaining to spine surgery involving surgical intervention. We searched bibliographies to identify additional relevant studies. Methodological quality was evaluated with AMSTAR score and graded with AMSTAR 2 criteria. Results: A total of 96 reviews met the eligibility criteria, with mean AMSTAR score of 7.51 (SD = 1.98). Based on AMSTAR 2 criteria, 13.5% (n = 13) and 18.7% (n = 18) of the studies had high and moderate level of confidence of results, respectively, without any critical flaws. A total of 29.1% (n = 28) of the studies had at least 1 critical flaw and 38.5% (n = 37) of the studies had more than 1 critical flaw, so that their results have low and critically low confidence, respectively. Failure to analyze the conflict of interest of authors of primary studies included in review and lack of list of excluded studies with justification were the most common critical flaw. Regression analysis demonstrated that studies with funding and studies published in recent years were significantly associated with higher methodological quality. Conclusion: Despite improvement in methodological quality of systematic reviews and meta-analyses in spine surgery in current decade, a substantial proportion continue to show critical flaws. With increasing number of review articles in spine surgery, stringent measures must be taken to adhere to methodological quality by following PRISMA and AMSTAR guidelines to attain higher standards of evidence in published literature.

scholarly journals Methods used to meta-analyse results from interrupted time series studies: A methodological systematic review protocol

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 110
Author(s):  
Elizabeth Korevaar ◽  
Amalia Karahalios ◽  
Andrew B. Forbes ◽  
Simon L. Turner ◽  
Steve McDonald ◽  
...  
Keyword(s):  
Public Health ◽  
Time Series ◽  
Systematic Reviews ◽  
Data Extraction ◽  
Meta Analysis ◽  
Interrupted Time Series ◽  
Analysis Methods ◽  
Study Selection ◽  
The Individual ◽  
Meta Analyses

Background: Systematic reviews are used to inform healthcare decision making. In reviews that aim to examine the effects of organisational, policy change or public health interventions, or exposures, evidence from interrupted time series (ITS) studies may be included. A core component of many systematic reviews is meta-analysis, which is the statistical synthesis of results across studies. There is currently a lack of guidance informing the choice of meta-analysis methods for combining results from ITS studies, and there have been no studies examining the meta-analysis methods used in practice. This study therefore aims to describe current meta-analysis methods used in a cohort of reviews of ITS studies. Methods: We will identify the 100 most recent reviews (published between 1 January 2000 and 11 October 2019) that include meta-analyses of ITS studies from a search of eight electronic databases covering several disciplines (public health, psychology, education, economics). Study selection will be undertaken independently by two authors. Data extraction will be undertaken by one author, and for a random sample of the reviews, two authors. From eligible reviews we will extract details at the review level including discipline, type of interruption and any tools used to assess the risk of bias / methodological quality of included ITS studies; at the meta-analytic level we will extract type of outcome, effect measure(s), meta-analytic methods, and any methods used to re-analyse the individual ITS studies. Descriptive statistics will be used to summarise the data. Conclusions: This review will describe the methods used to meta-analyse results from ITS studies. Results from this review will inform future methods research examining how different meta-analysis methods perform, and ultimately, the development of guidance.

Reasons and factors associated with inconclusiveness of systematic reviews about interventions for neuropathic pain

2020 ◽  
Author(s):  
Svjetlana Dosenovic ◽  
Andria Dujmic ◽  
Danijela Nujic ◽  
Ivana Vuka ◽  
Goran Tintor ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Systematic Reviews ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Measurement Tool ◽  
Efficacy And Safety ◽  
Factors Associated ◽  
Explicit Statement ◽  
Cochrane Database

Aim: Systematic reviews (SRs) are frequently inconclusive. The aim of this study was to analyze factors associated with conclusiveness of SRs about efficacy and safety of interventions for neuropathic pain (NeuP). Materials & methods: The study protocol was registered in the PROSPERO database (No. CRD42015025831). Five electronic databases (Medical Literature Analysis and Retrieval System Online, Cochrane Database of Systematic Reviews, Cumulative Index for Nursing and Allied Health Literature, Database of Abstracts of Reviews of Effects and Psychological Information Database) were searched until July 2018 for SRs about NeuP management. Conclusion statements for efficacy and safety, and characteristics of SRs were analyzed. Conclusiveness was defined as explicit statement by the SR authors that one intervention is better/similar to the other in terms of efficacy and safety. Methodological quality of SRs was assessed with the AMSTAR (A MeaSurement Tool to Assess systematic Reviews) tool. Results: Of 160 SRs, 37 (23%) were conclusive for efficacy and/or safety. In the SRs, conclusions about safety were missing in half of the analyzed abstracts, and a third of the full texts. Conclusive SRs included significantly more trials and participants, searched more databases, had more authors, conducted meta-analysis, analyzed quality of evidence, and had lower methodological quality than inconclusive SRs. The most common reasons for the lack of conclusiveness indicated by the SR authors were the small number of participants and trials, and the high heterogeneity of included studies. Conclusion: Most SRs about NeuP treatment were inconclusive. Sources of inconclusiveness of NeuP reviews need to be further studied, and SR authors need to provide conclusions about both safety and efficacy of interventions.

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