Treatment Effect in Earlier Trials of Patients With Chronic Medical Conditions: A Meta-Epidemiologic Study
| Autor: | Tamim Rajjo, M. Hassan Murad, Ahmed T. Ahmed, Wigdan Farah, Amrit Kanwar, Fares Alahdab, Jehad Almasri, Mouaz Alsawas, Noor Asi, Zayd Razouki, Khalid Benkhadra, Raed Benkhadra, Zhen Wang, Patricia Barrionuevo, Yifan Pang, Feras Zaiem |
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| Rok vydání: | 2018 |
| Předmět: |
Research design
medicine.medical_specialty Blinding MEDLINE 01 natural sciences law.invention 03 medical and health sciences 0302 clinical medicine Bias Randomized controlled trial law Internal medicine Humans Medicine Treatment effect 030212 general & internal medicine Intervention Duration 0101 mathematics Randomized Controlled Trials as Topic business.industry 010102 general mathematics General Medicine Publication bias Epidemiologic Studies Treatment Outcome Research Design Meta-analysis Chronic Disease business |
| Zdroj: | Mayo Clinic Proceedings. 93:278-283 |
| ISSN: | 0025-6196 |
| DOI: | 10.1016/j.mayocp.2017.10.020 |
| Popis: | Objective To determine whether the early trials in chronic medical conditions demonstrate an effect size that is larger than that in subsequent trials. Methods We identified randomized controlled trials (RCTs) evaluating a drug or device in patients with chronic medical conditions through meta-analyses (MAs) published between January 1, 2007, and June 23, 2015, in the 10 general medical journals with highest impact factor. We estimated the prevalence of having the largest effect size or heterogeneity in the first 2 published trials. We evaluated the association of the exaggerated early effect with several a priori hypothesized explanatory variables. Results We included 70 MAs that had included a total of 930 trials (average of 13 [range, 5-48] RCTs per MA) with average follow-up of 24 (range, 1-168) months. The prevalence of the exaggerated early effect (ie, proportion of MAs with largest effect or heterogeneity in the first 2 trials) was 37%. These early trials had an effect size that was on average 2.67 times larger than the overall pooled effect size (ratio of relative effects, 2.67; 95% CI, 2.12-3.37). The presence of exaggerated effect was not significantly associated with trial size; number of events; length of follow-up; intervention duration; number of study sites; inpatient versus outpatient setting; funding source; stopping a trial early; adequacy of random sequence generation, allocation concealment, or blinding; loss to follow-up or the test for publication bias. Conclusion Trials evaluating treatments of chronic medical conditions published early in the chain of evidence commonly demonstrate an exaggerated treatment effect compared with subsequent trials. At the present time, this phenomenon remains unpredictable. Considering the increasing morbidity and mortality of chronic medical conditions, decision makers should act on early evidence with caution. |
| Databáze: | OpenAIRE |
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