The empirical evidence of bias in trials measuring treatment differences
Berkman ND, Santaguida PL, Viswanathan M, Morton SC
Record ID 32014001113
English
Authors' objectives:
To comprehensively and systematically review and compare empirical evaluations of specific types of bias on effect estimates in randomized controlled trials (RCTs) reported in systematic reviews.
Authors' recommendations:
Theory suggests that bias in the conduct of studies would influence treatment effects. Our review found some evidence of this effect in relation to some aspects of RCT study conduct. When the bias was present, commonly the treatment effect was increased, but rarely were the estimates precise in the individual studies. However, because this evidence is limited and uncertain with respect to the magnitude of the impact, this does not necessarily imply that systematic reviewers can eliminate assessment of risk of bias. Due to the complexity of evaluating precision in meta-epidemiological studies developed from potentially heterogeneous
meta-analyses or trials, we cannot be sure that studies were sufficiently powered. We suggest that systematic reviewers consider subgroup analyses, with and without studies with flaws in relation to specific biases of importance for review questions. Future studies evaluating the impact of biases on treatment effect should follow the lead of the BRANDO study and use modeling approaches that include careful construction of large datasets of trials (and eventually observational studies) designed to look at the effect of specific aspects of study conduct and the interrelationship between bias concerns.
Details
Project Status:
Completed
Year Published:
2014
URL for published report:
https://www.ncbi.nlm.nih.gov/books/NBK253181/
English language abstract:
An English language summary is available
Publication Type:
Not Assigned
Country:
United States
MeSH Terms
- Bias
- Outcome Assessment, Health Care
- Treatment Outcome
- Research Design
- Clinical Trials as Topic
Contact
Organisation Name:
Agency for Healthcare Research and Quality
Contact Address:
Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;
Contact Name:
martin.erlichman@ahrq.hhs.gov
Contact Email:
martin.erlichman@ahrq.hhs.gov
Copyright:
Agency for Healthcare Research and Quality (AHRQ)
This is a bibliographic record of a published health technology assessment from a member of INAHTA or other HTA producer. No evaluation of the quality of this assessment has been made for the HTA database.