Importance of sample size determination for randomized controlled clinical trials for coronavirus disease 2019 antiviral therapies

Abstract

This commentary focuses on factors related to sample size determination in randomized controlled clinical trials (RCTs) for antiviral therapies against coronavirus disease 2019 (COVID-19) published during the pandemic of COVID-19.The articles involved in the following discussions include a total of 55 original articles on RCTs for antiviral treatments of patients with COVID-19, including the 36 articles mentioned in our previous commentary 1 and 19 original articles added recently based on a search at PubMed and some from other sources. In terms of sample size determination, 33 of 55 (60.0%) RCTs determined their sample size via calculation; in seven (12.7%) of the 55 RCTs the sample size was not determined via calculation; 15 articles did not mention how the sample size was determined. Of the 55 RCT articles, 21 (38.2%) were regarded by the authors or others as having small or too small sample sizes to be able to support the study hypothesis or obtain the expected evidence.These results suggest that considerably high proportions of RCTs authors for antiviral therapies for COVID-19 did not consider sample size determination as an important factor for the success of RCTs, up to 40% of the 55 RCT articles