Comparison of pre-COVID-19 pandemic, lockdown, and postlockdown participant adherence in a phase IV clinical trial for the treatment of postexposure rabies prophylaxis.

Context: One of the most frequent difficulties encountered in clinical trials is the failure to retain participants and this is doubly important when the disease is 100% fatal. Studies conducted during the COVID-19 pandemic regarding adherence have been equivocal. Aims: The aim of this study is to compare participant adherence in a phase IV clinical trial for postexposure rabies prophylaxis before the pandemic, during lockdown, and after lockdown. Settings and Design: An observational study (audit). Subjects and Methods: The study in May 2023 covers the period from October 2019 to March 2022. Individual participant files of recruited participants were examined for adherence to treatment in the prepandemic period, during lockdown, and postlockdown eras. Statistical Analysis Used: The primary outcome measure-participant adherence anti-rabies vaccination (ARV completion) in the three timelines was compared using the Chi-squared test. The secondary outcome measures: reasons for nonadherence and potential factors associated with it done by univariate followed by multivariate logistic regression. All analyses conducted at a 5% significance level. Results: A total of 455 (2046 ARV visits) participants were recruited in the original Phase IV study, with a mean (±standard deviation) age of 31.9 ± 16.23 years. The COVID-19 lockdown reported the highest nonadherence to ARV (5/26, 19%) due to travel restriction and fear of contracting SARS-CoV2 infection compared to prepandemic (9/144, 6%) and postlockdown (6/285, 2%) periods. Conclusion: There was a significant reduction in participant adherence for ARV completion during the lockdown compared to the prepandemic and postlockdown timelines. Decentralized Clinical Trials may offer potential solutions to improve adherence in the context of epidemics and pandemics.