Two ‐stage or not two‐stage? That is the question for IPD meta‐analysis projects
AbstractIndividual participant data meta-analysis (IPDMA) projects obtain, check, harmonise and synthesise raw data from multiple studies. When undertaking the meta-analysis, researchers must decide between a two-stage or a one-stage approach. In a two-stage approach, the IPD are first analysed separately within each study to obtain aggregate data (e.g., treatment effect estimates and standard errors); then, in the second stage, these aggregate data are combined in a standard meta-analysis model (e.g., common-effect or random-effects). In a one-stage approach, the IPD from all studies are analysed in a single step using an...
Source: Research Synthesis Methods - August 22, 2023 Category: Chemistry Authors: Richard D. Riley,
Joie Ensor,
Miriam Hattle,
Katerina Papadimitropoulou,
Tim P. Morris Tags: RESEARCH IN BRIEF Source Type: research
Advice for improving the reproducibility of data extraction in meta ‐analysis
AbstractExtracting data from studies is the norm in meta-analyses, enabling researchers to generate effect sizes when raw data are otherwise not available. While there has been a general push for increased reproducibility in meta-analysis, the transparency and reproducibility of the data extraction phase is still lagging behind. Unfortunately, there is little guidance of how to make this process more transparent and shareable. To address this, we provide several steps to help increase the reproducibility of data extraction in meta-analysis. We also provide suggestions of R software that can further help with reproducible d...
Source: Research Synthesis Methods - August 12, 2023 Category: Chemistry Authors: Edward R. Ivimey ‐Cook,
Daniel W. A. Noble,
Shinichi Nakagawa,
Marc J. Lajeunesse,
Joel L. Pick Tags: RESEARCH IN BRIEF Source Type: research
Combining meta ‐analysis with multiple imputation for one‐step, privacy‐protecting estimation of causal treatment effects in multi‐site studies
AbstractMissing data complicates statistical analyses in multi-site studies, especially when it is not feasible to centrally pool individual-level data across sites. We combined meta-analysis with within-site multiple imputation for one-step estimation of the average causal effect (ACE) of a target population comprised of all individuals from all data-contributing sites within a multi-site distributed data network, without the need for sharing individual-level data to handle missing data. We considered two orders of combination and three choices of weights for meta-analysis, resulting in six approaches. The first three app...
Source: Research Synthesis Methods - August 2, 2023 Category: Chemistry Authors: Di Shu,
Xiaojuan Li,
Qoua Her,
Jenna Wong,
Dongdong Li,
Rui Wang,
Sengwee Toh Tags: RESEARCH ARTICLE Source Type: research
Inclusive critical appraisal of qualitative and quantitative findings in evidence synthesis
AbstractA diversity of approaches for critically appraising qualitative and quantitative evidence exist and emphasize different aspects. These approaches lack clear processes to facilitate rating the overall quality of the evidence for aggregated findings that combine qualitative and quantitative evidence. We draw on a meta-aggregation of implementation and process evaluations to illustrate a method for critically appraising empirical findings generated from qualitative and quantitative studies. This method includes a rubric for standardizing assessments of the overall quality of evidence in an evidence synthesis or mixed-...
Source: Research Synthesis Methods - August 1, 2023 Category: Chemistry Authors: Ajima Olaghere,
David B. Wilson,
Catherine Kimbrell Tags: RESEARCH ARTICLE Source Type: research
Estimating pairwise overlap in umbrella reviews: Considerations for using the corrected covered area (CCA) index methodology
AbstractUmbrella reviews (reviews of systematic reviews) are increasingly used to synthesize findings from systematic reviews. One important challenge when pooling data from several systematic reviews is publication overlap, that is, the same primary publications being included in multiple reviews. Pieper et al. have proposed using the corrected covered area (CCA) index to quantify the degree of overlap between systematic reviews to be pooled in an umbrella review. Recently, this methodology has been integrated in Excel- or R-based tools for easier use. In this short letter, we highlight an important consideration for usin...
Source: Research Synthesis Methods - July 28, 2023 Category: Chemistry Authors: Mariam Kirvalidze,
Ahmad Abbadi,
Lena Dahlberg,
Lawrence B. Sacco,
Amaia Calder ón‐Larrañaga,
Lucas Morin Tags: RESEARCH IN BRIEF Source Type: research
Evaluation of the interim Cochrane rapid review methods guidance —A mixed‐methods study on the understanding of and adherence to the guidance
The objective of this mixed-methods study was to assess the adherence and investigate authors' understanding of the RRMG guidance. We identified all documents citing the Interim Cochrane RRMG guidance up to February 17, 2022 and performed an exploratory adherence analysis. We interviewed 20 RR authors to assess the recommendations' comprehensibility and reasons for any deviations. Further, we surveyed nine authors of COVID-19-related Cochrane reviews for their reasons for not conducting a RR. We analyzed 128 RRs (111 non-Cochrane, 17 Cochrane) that cited the RRMG guidance. Several recommendations were not followed by a lar...
Source: Research Synthesis Methods - July 22, 2023 Category: Chemistry Authors: Ursula Griebler,
Andreea Dobrescu,
Dominic Ledinger,
Pauline Klingenstein,
Isolde Sommer,
Robert Emprechtinger,
Emma Persad,
Arianna Gadinger,
Marialena Trivella,
Irma Klerings,
Barbara Nussbaumer ‐Streit Tags: RESEARCH ARTICLE Source Type: research
Critical appraisal tools used in systematic reviews of in vitro cell culture studies: A methodological study
AbstractSystematic reviews (SRs) of preclinical studies are marked with poor methodological quality. In vitro studies lack assessment tools to improve the quality of preclinical research. This methodological study aimed to identify, collect, and analyze SRs based on cell culture studies to highlight the current appraisal tools utilized to support the development of a validated critical appraisal tool for cell culture in vitro research. SRs, scoping reviews, and meta-analyses that included cell culture studies and used any type of critical appraisal tool were included. Electronic search, study selection, data collection and...
Source: Research Synthesis Methods - July 19, 2023 Category: Chemistry Authors: Victor Paiva Barbosa,
Bruna Bastos Silveira,
Juliana Amorim dos Santos,
Mylene Martins Monteiro,
Ricardo D. Coletta,
Graziela De Luca Canto,
Cristine Miron Stefani,
Eliete Neves Silva Guerra Tags: REVIEW Source Type: research
Accounting for time dependency in meta ‐analyses of concordance probability estimates
AbstractRecent years have seen the development of many novel scoring tools for disease prognosis and prediction. To become accepted for use in clinical applications, these tools have to be validated on external data. In practice, validation is often hampered by logistical issues, resulting in multiple small-sized validation studies. It is therefore necessary to synthesize the results of these studies using techniques for meta-analysis. Here we consider strategies for meta analyzing the concordance probability for time-to-event data ( “C-index ”), which has become a popular tool to evaluate the discriminatory power of p...
Source: Research Synthesis Methods - July 11, 2023 Category: Chemistry Authors: Matthias Schmid,
Tim Friede,
Nadja Klein,
Leonie Weinhold Tags: RESEARCH ARTICLE Source Type: research
Meta ‐analyzing partial correlation coefficients using Fisher's z transformation
AbstractThe partial correlation coefficient (PCC) is used to quantify the linear relationship between two variables while taking into account/controlling for other variables. Researchers frequently synthesize PCCs in a meta-analysis, but two of the assumptions of the common equal-effect and random-effects meta-analysis model are by definition violated. First, the sampling variance of the PCC cannot assumed to be known, because the sampling variance is a function of the PCC. Second, the sampling distribution of each primary study's PCC is not normal since PCCs are bounded between −1 and 1. I advocate applying the Fisher's...
Source: Research Synthesis Methods - July 9, 2023 Category: Chemistry Authors: Robbie C. M. Aert Tags: DISCUSSION Source Type: research
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Source: Research Synthesis Methods - July 7, 2023 Category: Chemistry Tags: ISSUE INFORMATION Source Type: research
Population adjusted ‐indirect comparisons in health technology assessment: A methodological systematic review
AbstractIn health technology assessment (HTA), population-adjusted indirect comparisons (PAICs) are increasingly considered to adjust for the difference in the target population between studies. We aim to assess the conduct and reporting of PAICs in recent HTA practice, by performing, a methodological systematic review of studies implementing PAICs from PubMed, EMBASE Classic, Embase/Ovid Medline All, and Cochrane databases from January 1, 2010 to Feb 13, 2023. Four independent researchers screened the titles, abstracts, and full-texts of the identified records, then extracted data on methodological and reporting character...
Source: Research Synthesis Methods - July 4, 2023 Category: Chemistry Authors: Bang Truong,
Lan ‐Anh T. Tran,
Tuan Anh Le,
Thi Thu Pham,
Tat‐Thang Vo Tags: REVIEW Source Type: research
Kenward ‐Roger–type corrections for inference methods of network meta‐analysis and meta‐regression
AbstractNetwork meta-analysis has been an essential methodology of systematic reviews for comparative effectiveness research. The restricted maximum likelihood (REML) method is one of the current standard inference methods for multivariate, contrast-based meta-analysis models, but recent studies have revealed the resultant confidence intervals of average treatment effect parameters in random-effects models can seriously underestimate statistical errors; that is, the actual coverage probability of a true parameter cannot retain the nominal level (e.g., 95%). In this article, we provided improved inference methods for the ne...
Source: Research Synthesis Methods - July 3, 2023 Category: Chemistry Authors: Hisashi Noma,
Yasuyuki Hamura,
Masahiko Gosho,
Toshi A. Furukawa Tags: RESEARCH ARTICLE Source Type: research
Improved methods to construct prediction intervals for network meta ‐analysis
AbstractNetwork meta-analysis has played an important role in evidence-based medicine for assessing the comparative effectiveness of multiple available treatments. The prediction interval has been one of the standard outputs in recent network meta-analysis as an effective measure that enables simultaneous assessment of uncertainties in treatment effects and heterogeneity among studies. To construct the prediction interval, a large-sample approximating method based on thet-distribution has generally been applied in practice; however, recent studies have shown that similart-approximation methods for conventional pairwise met...
Source: Research Synthesis Methods - July 3, 2023 Category: Chemistry Authors: Hisashi Noma,
Yasuyuki Hamura,
Shonosuke Sugasawa,
Toshi A. Furukawa Tags: RESEARCH ARTICLE Source Type: research
Calculating the power of a planned individual participant data meta ‐analysis of randomised trials to examine a treatment‐covariate interaction with a time‐to‐event outcome
AbstractBefore embarking on an individual participant data meta-analysis (IPDMA) project, researchers should consider the power of their planned IPDMA conditional on the studies promising their IPD and their characteristics. Such power estimates help inform whether the IPDMA project is worth the time and funding investment, before IPD are collected. Here, we suggest how to estimate the power of a planned IPDMA of randomised trials aiming to examine treatment-covariate interactions at the participant-level (i.e., treatment effect modifiers). We focus on a time-to-event (survival) outcome with a binary or continuous covariat...
Source: Research Synthesis Methods - June 30, 2023 Category: Chemistry Authors: Richard D. Riley,
Gary S. Collins,
Miriam Hattle,
Rebecca Whittle,
Joie Ensor Tags: RESEARCH ARTICLE Source Type: research
Estimation of heterogeneity variance based on a generalized Q statistic in meta ‐analysis of log‐odds‐ratio
AbstractFor estimation of heterogeneity variance τ2$$ {\tau}^2 $$ in meta-analysis of log-odds-ratio, we derive new mean- and median-unbiased point estimators and new interval estimators based on a generalized Q$$ Q $$ statistic, QF$$ {Q}_F $$, in which the weights depend on only the studies' effective sample sizes. We compare them with familiar estimators based on the inverse-variance-weights version of Q$$ Q $$, QIV.$$ {Q}_{IV}. $$ In an extensive simulation, we studied the bias (including median bias) of the point estimators and the coverage (including left and right coverage error) of the confidence intervals. Most es...
Source: Research Synthesis Methods - June 29, 2023 Category: Chemistry Authors: Elena Kulinskaya,
David C. Hoaglin Tags: RESEARCH ARTICLE Source Type: research
