Download the full-sized PDF of Quantifying bias in randomized controlled trials in child health: a meta-epidemiological study.Download the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Pediatrics, Department of


This file is in the following collections:

Alberta Research Centre for Health Evidence (ARCHE)

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


Author or creator
Hartling, L.
Hamm, M. P.
Fernandes, R. M.
Dryden, D. M.
Vandermeer, B.
Additional contributors
randomized controlled trial
child health
systematic reviews
drug therapy
Type of item
Journal Article (Published)
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.
Date created
License information
Creative Commons Attribution-Non-Commercial 3.0 Unported

Citation for previous publication
Hartling, L., Hamm, M. P., Fernandes, R. M., Dryden, D. M., & Vandermeer, B. (2014). Quantifying bias in randomized controlled trials in child health: a meta-epidemiological study. PLoS One, 9(2), e88008. doi: 10.1371/journal.pone.0088008
Link to related item

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 140570
Last modified: 2015:10:12 12:07:55-06:00
Filename: PLoS_9_2_e88008.pdf
Original checksum: 0a490477decbb3c6f72c71de8f86f5ae
Well formed: false
Valid: false
Status message: Unexpected error in findFonts java.lang.ClassCastException: edu.harvard.hul.ois.jhove.module.pdf.PdfSimpleObject cannot be cast to edu.harvard.hul.ois.jhove.module.pdf.PdfDictionary offset=2861
Page count: 6
Activity of users you follow
User Activity Date