1. Randomized clinical trials with run-in periods: frequency, characteristics and reporting
- Author
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Laursen DRT, Paludan-Müller AS, and Hróbjartsson A
- Subjects
lead-in periods ,enrichment design ,single-blind placebo ,washout period ,research methodology ,Infectious and parasitic diseases ,RC109-216 - Abstract
David Ruben Teindl Laursen,1–4 Asger Sand Paludan-Müller,2 Asbjørn Hróbjartsson1,3,4 1Centre for Evidence-Based Medicine Odense (CEBMO), Odense University Hospital, Odense, Denmark; 2Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark; 3Department of Clinical Research, University of Southern Denmark, Odense, Denmark; 4Odense Patient data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark Background: Run-in periods are occasionally used in randomized clinical trials to exclude patients after inclusion, but before randomization. In theory, run-in periods increase the probability of detecting a potential treatment effect, at the cost of possibly affecting external and internal validity. Adequate reporting of exclusions during the run-in period is a prerequisite for judging the risk of compromised validity. Our study aims were to assess the proportion of randomized clinical trials with run-in periods, to characterize such trials and the types of run-in periods and to assess their reporting. Materials and methods: This was an observational study of 470 PubMed-indexed randomized controlled trial publications from 2014. We compared trials with and without run-in periods, described the types of run-in periods and evaluated the completeness of their reporting by noting whether publications stated the number of excluded patients, reasons for exclusion and baseline characteristics of the excluded patients. Results: Twenty-five trials reported a run-in period (5%). These were larger than other trials (median number of randomized patients 217 vs 90, P=0.01) and more commonly industry trials (11% vs 3%, P more...
- Published
- 2019