Dataset Information

Quantifying bias in randomized controlled trials in child health: a meta-epidemiological study.

ABSTRACT:

Objective

To quantify bias related to specific methodological characteristics in child-relevant randomized controlled trials (RCTs).

Design

Meta-epidemiological study.

Data sources

We identified systematic reviews containing a meta-analysis with 10-40 RCTs that were relevant to child health in the Cochrane Database of Systematic Reviews.

Data extraction

Two reviewers independently assessed RCTs using items in the Cochrane Risk of Bias tool and other study factors. We used meta-epidemiological methods to assess for differences in effect estimates between studies classified as high/unclear vs. low risk of bias.

Results

We included 287 RCTs from 17 meta-analyses. The proportion of studies at high/unclear risk of bias was: 79% sequence generation, 83% allocation concealment, 67% blinding of participants, 47% blinding of outcome assessment, 49% incomplete outcome data, 32% selective outcome reporting, 44% other sources of bias, 97% overall risk of bias, 56% funding, 35% baseline imbalance, 13% blocked randomization in unblinded trials, and 1% early stopping for benefit. We found no significant differences in effect estimates for studies that were high/unclear vs. low risk of bias for any of the risk of bias domains, overall risk of bias, or other study factors.

Conclusions

We found no differences in effect estimates between studies based on risk of bias. A potential explanation is the number of trials included, in particular the small number of studies with low risk of bias. Until further evidence is available, reviewers should not exclude RCTs from systematic reviews and meta-analyses based solely on risk of bias particularly in the area of child health.

SUBMITTER: Hartling L

PROVIDER: S-EPMC3913714 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Quantifying bias in randomized controlled trials in child health: a meta-epidemiological study.

Hartling Lisa L Hamm Michele P MP Fernandes Ricardo M RM Dryden Donna M DM Vandermeer Ben B

PloS one 20140204 2

<h4>Objective</h4>To quantify bias related to specific methodological characteristics in child-relevant randomized controlled trials (RCTs).<h4>Design</h4>Meta-epidemiological study.<h4>Data sources</h4>We identified systematic reviews containing a meta-analysis with 10-40 RCTs that were relevant to child health in the Cochrane Database of Systematic Reviews.<h4>Data extraction</h4>Two reviewers independently assessed RCTs using items in the Cochrane Risk of Bias tool and other study factors. We ...[more]

PMID: 24505351

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Project description:IntroductionThe validity of systematic reviews and meta-analysis depends on methodological quality and unbiased dissemination of trials. Our objective is to evaluate the association of estimates of treatment effects with different bias-related study characteristics in meta-analyses of interventions used for treating pain in osteoarthritis (OA). From the findings, we hope to consolidate guidance on interpreting OA trials in systematic reviews based on empirical evidence from Cochrane reviews.Methods and analysisOnly systematic reviews that compare experimental interventions with sham, placebo or no intervention control will be considered eligible. Bias will be assessed with the risk of bias tool, used according to the Cochrane Collaboration's recommendations. Furthermore, center status, trial size and funding will be assessed. The primary outcome (pain) will be abstracted from the first appearing forest plot for overall pain in the Cochrane review. Treatment effect sizes will be expressed as standardised mean differences (SMDs), where the difference in mean values available from the forest plots is divided by the pooled SD. To empirically assess the risk of bias in treatment benefits, we will perform stratified analyses of the trials from the included meta-analyses and assess the interaction between trial characteristics and treatment effect. A relevant study-level covariate is defined as one that decreases the between-study variance (τ(2), estimated as Tau-squared) as a consequence of inclusion in the mixed effects statistical model.Ethics and disseminationMeta-analyses and randomised controlled trials provide the most reliable basis for treatment of patients with OA, but the actual impact of bias is unclear. This study will systematically examine the methodological quality in OA Cochrane reviews and explore the effect estimates behind possible bias. Since our study does not collect primary data, no formal ethical assessment and informed consent are required.Trial registration numberPROSPERO (CRD42013006924).

Dataset Information

Quantifying bias in randomized controlled trials in child health: a meta-epidemiological study.

Objective

Design

Data sources

Data extraction

Results

Conclusions

Publications

Quantifying bias in randomized controlled trials in child health: a meta-epidemiological study.

Similar Datasets

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