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Frequency of Use and Adequacy of Cochrane Risk of Bias Tool 2 in Non-Cochrane Systematic Reviews Published in 2020: Meta-Research Study
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Andrija Babic; Ognjen Barcot; Tomislav Viskovic; Frano Šaric; Aleksandar Kirkovski; Ivana Barun; Zvonimir Križanac; Roshan Arjun Ananda; Yuli Viviana Fuentes Barreiro; Narges Malih; Daiana Anne-Marie Dimcea; Josipa Ordulj; Ishanka Weerasekara; Matteo Spezia; Marija Franka Žuljevic; Jelena Šuto; Luca Tancredi; Andela Pijuk; Susanna Sammali; Veronica Iascone; Thilo Groote; Tina Poklepovic Pericic; Livia Puljak – Research Synthesis Methods, 2024
Risk of bias (RoB) assessment is essential to the systematic review methodology. The new version of the Cochrane RoB tool for randomized trials (RoB 2) was published in 2019 to address limitations identified since the first version of the tool was published in 2008 and to increase the reliability of assessments. This study analyzed the frequency…
Descriptors: Risk, Bias, Use Studies, Meta Analysis
Commercial Funding and Estimated Intervention Effects in Randomized Clinical Trials: Systematic Review of Meta-Epidemiological Studies
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Nejstgaard, Camilla Hansen; Laursen, David Ruben Teindl; Lundh, Andreas; Hróbjartsson, Asbjørn – Research Synthesis Methods, 2023
We investigated to which degree commercial funding is associated with estimated intervention effects in randomized trials. We included meta-epidemiological studies with published data on the association between commercial funding and results or conclusions of randomized trials. We searched five databases and other sources. We selected one result…
Descriptors: Private Financial Support, Intervention, Randomized Controlled Trials, Literature Reviews
Individual Participant Data Meta-Analysis to Examine Linear or Non-Linear Treatment-Covariate Interactions at Multiple Time-Points for a Continuous Outcome
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Miriam Hattle; Joie Ensor; Katie Scandrett; Marienke van Middelkoop; Danielle A. van der Windt; Melanie A. Holden; Richard D. Riley – Research Synthesis Methods, 2024
Individual participant data (IPD) meta-analysis projects obtain, harmonise, and synthesise original data from multiple studies. Many IPD meta-analyses of randomised trials are initiated to identify treatment effect modifiers at the individual level, thus requiring statistical modelling of interactions between treatment effect and participant-level…
Descriptors: Meta Analysis, Randomized Controlled Trials, Outcomes of Treatment, Evaluation Methods
Combining Meta-Epidemiological Study Datasets on Commercial Funding of Randomised Clinical Trials: Database, Methods, and Descriptive Results of the COMFIT Study
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Nejstgaard, Camilla Hansen; Lundh, Andreas; Abdi, Suhayb; Clayton, Gemma; Gelle, Mustafe Hassan Adan; Laursen, David Ruben Teindl; Olorisade, Babatunde Kazeem; Savovic, Jelena; Hróbjartsson, Asbjørn – Research Synthesis Methods, 2022
Randomised trials are often funded by commercial companies and methodological studies support a widely held suspicion that commercial funding may influence trial results and conclusions. However, these studies often have a risk of confounding and reporting bias. The risk of confounding is markedly reduced in meta-epidemiological studies that…
Descriptors: Medical Research, Randomized Controlled Trials, Corporations, Financial Support
Multivariate Network Meta-Analysis of Survival Function Parameters
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Cope, Shannon; Chan, Keith; Jansen, Jeroen P. – Research Synthesis Methods, 2020
Background: Network meta-analysis (NMA) of survival data with a multidimensional treatment effect has been introduced as an alternative to NMA based on the proportional hazards assumption. However, these flexible models have some limitations, such as the use of an approximate likelihood based on discrete hazards, rather than a likelihood for…
Descriptors: Multivariate Analysis, Meta Analysis, Network Analysis, Models
Individual Participant Data Meta-Analysis of Intervention Studies with Time-to-Event Outcomes: A Review of the Methodology and an Applied Example
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de Jong, Valentijn M. T.; Moons, Karel G. M.; Riley, Richard D.; Tudur Smith, Catrin; Marson, Anthony G.; Eijkemans, Marinus J. C.; Debray, Thomas P. A. – Research Synthesis Methods, 2020
Many randomized trials evaluate an intervention effect on time-to-event outcomes. Individual participant data (IPD) from such trials can be obtained and combined in a so-called IPD meta-analysis (IPD-MA), to summarize the overall intervention effect. We performed a narrative literature review to provide an overview of methods for conducting an…
Descriptors: Meta Analysis, Intervention, Randomized Controlled Trials, Guidelines
Ten Questions to Consider When Interpreting Results of a Meta-Epidemiological Study--The MetaBLIND Study as a Case
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Moustgaard, Helene; Jones, Hayley E.; Savovic, Jelena; Clayton, Gemma L.; Sterne, Jonathan AC; Higgins, Julian PT; Hróbjartsson, Asbjørn – Research Synthesis Methods, 2020
Randomized clinical trials underpin evidence-based clinical practice, but flaws in their conduct may lead to biased estimates of intervention effects and hence invalid treatment recommendations. The main approach to the empirical study of bias is to collate a number of meta-analyses and, within each, compare the results of trials with and without…
Descriptors: Epidemiology, Evidence, Medical Research, Intervention
Randomization Methods in Emergency Setting Trials: A Descriptive Review
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Corbett, Mark Stephen; Moe-Byrne, Thirimon; Oddie, Sam; McGuire, William – Research Synthesis Methods, 2016
Background: Quasi-randomization might expedite recruitment into trials in emergency care settings but may also introduce selection bias. Methods: We searched the Cochrane Library and other databases for systematic reviews of interventions in emergency medicine or urgent care settings. We assessed selection bias (baseline imbalances) in prognostic…
Descriptors: Quasiexperimental Design, Randomized Controlled Trials, Medical Services, Medicine
Non-Randomized Studies as a Source of Complementary, Sequential or Replacement Evidence for Randomized Controlled Trials in Systematic Reviews on the Effects of Interventions
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Schünemann, Holger J.; Tugwell, Peter; Reeves, Barnaby C.; Akl, Elie A.; Santesso, Nancy; Spencer, Frederick A.; Shea, Beverley; Wells, George; Helfand, Mark – Research Synthesis Methods, 2013
The terms applicability, generalizability, external validity and transferability are related, sometimes used interchangeably and have in common that they lack a clear and consistent definition in the classic epidemiological literature. However, all of these terms generally describe one overarching theme: whether or not available research evidence…
Descriptors: Intervention, Randomized Controlled Trials, Literature Reviews, Comparative Analysis
Issues Relating to Confounding and Meta-analysis When Including Non-Randomized Studies in Systematic Reviews on the Effects of Interventions
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Valentine, Jeffrey C.; Thompson, Simon G. – Research Synthesis Methods, 2013
Background: Confounding caused by selection bias is often a key difference between non-randomized studies (NRS) and randomized controlled trials (RCTs) of interventions. Key methodological issues: In this third paper of the series, we consider issues relating to the inclusion of NRS in systematic reviews on the effects of interventions. We discuss…
Descriptors: Research Design, Randomized Controlled Trials, Intervention, Bias
Combining Randomized and Non-Randomized Evidence in Clinical Research: A Review of Methods and Applications
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Verde, Pablo E.; Ohmann, Christian – Research Synthesis Methods, 2015
Researchers may have multiple motivations for combining disparate pieces of evidence in a meta-analysis, such as generalizing experimental results or increasing the power to detect an effect that a single study is not able to detect. However, while in meta-analysis, the main question may be simple, the structure of evidence available to answer it…
Descriptors: Randomized Controlled Trials, Bayesian Statistics, Comparative Analysis, Evidence
Issues Relating to Selective Reporting When Including Non-Randomized Studies in Systematic Reviews on the Effects of Healthcare Interventions
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Norris, Susan L.; Moher, David; Reeves, Barnaby C.; Shea, Beverley; Loke, Yoon; Garner, Sarah; Anderson, Laurie; Tugwell, Peter; Wells, George – Research Synthesis Methods, 2013
Background: Selective outcome and analysis reporting (SOR and SAR) occur when only a subset of outcomes measured and analyzed in a study is fully reported, and are an important source of potential bias. Key methodological issues: We describe what is known about the prevalence and effects of SOR and SAR in both randomized controlled trials (RCTs)…
Descriptors: Health Services, Intervention, Outcomes of Treatment, Research Methodology