Abstract
To analyze the temporal trend in enrollment rates in a COVID-19 platform trial during the first three waves of the pandemic in the United States. DESIGN: Secondary analysis of data from the I-SPY COVID randomized controlled trial (RCT). SETTING: Thirty-one hospitals throughout the United States. PATIENTS: Patients who were approached, either directly or via a legally authorized representative, for consent and enrollment into the I-SPY COVID RCT. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 1,338 patients approached for the I-SPY COVID trial from July 30, 2020, to February 17, 2022, the number of patients who enrolled (n = 1,063) versus declined participation (n = 275) was used to calculate monthly enrollment rates. Overall, demographic and baseline clinical characteristics were similar between those who enrolled versus declined. Enrollment rates fluctuated over the course of the COVID-19 pandemic, but there were no significant trends over time (Mann-Kendall test, p = 0.21). Enrollment rates were also comparable between vaccinated and unvaccinated patients. In multivariable logistic regression analysis, age, sex, region of residence, COVID-19 severity of illness, and vaccination status were not significantly associated with the decision to decline consent. CONCLUSIONS: In this secondary analysis of the I-SPY COVID clinical trial, there was no significant association between the enrollment rate and time period or vaccination status among all eligible patients approached for clinical trial participation. Additional studies are needed to better understand whether the COVID-19 pandemic has altered clinical trial participation and to develop strategies for encouraging participation in future COVID-19 and critical care clinical trials.