Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials
et al., Cochrane Database of Systematic Reviews, doi:10.1002/14651858.MR000034.pub2, Apr 2014
Meta-analysis of 14 methodological reviews encompassing 1,583 meta-analyses and 228 medical conditions, showing no significant difference in treatment effect estimates between randomized controlled trials (RCTs) and observational studies. The pooled ratio of odds ratios comparing RCTs to observational studies was 1.08 (95% CI 0.96-1.22), indicating observational studies may show slightly smaller effects than RCTs but the difference was not statistically significant. This finding held across different types of observational studies (cohort, case-control), pharmacological versus non-pharmacological interventions, and studies using propensity score adjustments. The authors conclude that factors other than study design itself need to be considered when exploring disagreements between RCTs and observational studies, as the choice of study design alone does not consistently result in systematically different effect estimates.
Anglemyer et al., 29 Apr 2014, peer-reviewed, 3 authors.
Contact: berol@pharmacy.ucsf.edu.
Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials
Cochrane Database of Systematic Reviews, doi:10.1002/14651858.mr000034.pub2
Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials.
Additional references Altman 2003 Altman D, Bland J. Interaction revisited: the difference between two estimates. BMJ 2003;326:219.
Dorsey 2010 Dorsey ER, de Roulet J, Thompson JP, Reminick JL, Thai A, White-Stellato Z, et al. Funding of US Biomedical Research, 2003 -2008 . JAMA 2010; 303(2) :137-43.
Higgins 2011 Higgins JPT, Green S (editors
C O N T R I B U T I O N S O F A U T H O R S All authors contributed to drafting of the review. LB conceived the idea for the study. THH conducted all searches and reviewed the final manuscript. LB and AA screened titles, wrote the final manuscript, and revised the manuscript in response to peer review comments. AA conducted all analyses.
D E C L A R A T I O N S O F I N T E R E S T None to declare.
S O U R C E S O F S U P P O R T Internal sources • Clinical and Translational Sciences Institute (CTSI), University of California, San Francisco (UCSF), USA.
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