All Times EDT
Keywords: Subsequent therapy, Survival analysis
Subsequent therapy is often present in modern clinical trials as supplemental treatment or post study therapy. Subsequent therapy may be administered during some period of observation on study as standard practice for patient care or after the experimental treatment is completed, e.g., when a patient might need additional therapy due to failure of the study treatment. We explore the impact of time-varying subsequent therapy on the statistical power and treatment effects in survival analysis. Novel methods to analyze the impact of subsequent therapy in time-to-event endpoints will be discussed. Both simulations and real case studies will be used to evaluate the pros and cons of different statistical approaches. The study demonstrated the importance of accounting for time-varying subsequent therapy for obtaining unbiased interpretation of data.