Availability of Large-scale Evidence on Specific Harms from Systematic Reviews of Randomized Trials
Overview
Affiliations
Purpose: To assess how frequently systematic reviews of randomized controlled trials convey large-scale evidence on specific, well-defined adverse events.
Methods: We searched the Cochrane Database of Systematic Reviews for reviews containing quantitative data on specific, well-defined harms for at least 4000 randomized subjects, the minimum sample required for adequate power to detect an adverse event due to an intervention in 1% of subjects. Main outcome measures included the number of reviews with eligible large-scale data on adverse events, the number of ineligible reviews, and the magnitude of recorded harms (absolute risk, relative risk) based on large-scale evidence.
Results: Of 1727 reviews, 138 included evidence on > or =4000 subjects. Only 25 (18%) had eligible data on adverse events, while 77 had no harms data, and 36 had data on harms that were nonspecific or pertained to <4000 subjects. Of 66 specific adverse events for which there were adequate data in the 25 eligible reviews, 25 showed statistically significant differences between comparison arms; most pertained to serious or severe adverse events and absolute risk differences <4%. In 29% (9/31) of a sample of large trials in reviews with poor reporting of harms, specific harms were presented adequately in the trial reports but were not included in the systematic reviews.
Conclusion: Systematic reviews can convey useful large-scale information on adverse events. Acknowledging the importance and difficulties of studying harms, reporting of adverse effects must be improved in both randomized trials and systematic reviews.
Mayo-Wilson E, Qureshi R, Li T Syst Rev. 2023; 12(1):67.
PMID: 37061724 PMC: 10105415. DOI: 10.1186/s13643-023-02234-0.
To Expand the Evidence Base About Harms from Tests and Treatments.
Korenstein D, Harris R, Elshaug A, Ross J, Morgan D, Cooper R J Gen Intern Med. 2021; 36(7):2105-2110.
PMID: 33479928 PMC: 8298733. DOI: 10.1007/s11606-021-06597-9.
Montroy J, Berjawi R, Lalu M, Podolsky E, Peixoto C, Sahin L BMC Gastroenterol. 2020; 20(1):372.
PMID: 33167889 PMC: 7653724. DOI: 10.1186/s12876-020-01516-4.
Beta-blockers for suspected or diagnosed acute myocardial infarction.
Safi S, Sethi N, Nielsen E, Feinberg J, Jakobsen J, Gluud C Cochrane Database Syst Rev. 2019; 12:CD012484.
PMID: 31845756 PMC: 6915833. DOI: 10.1002/14651858.CD012484.pub2.
Bolton M, Hodkinson A, Boda S, Mould A, Panagioti M, Rhodes S BMC Med. 2019; 17(1):10.
PMID: 30642329 PMC: 6332608. DOI: 10.1186/s12916-018-1242-0.