Sequential Surveillance for Drug Safety in a Regulatory Environment

Sequential surveillance for drug safety using electronic health data extends the concepts developed for sequential monitoring in randomized clinical trials and in post-licensure vaccine safety studies. Additional challenges in the postmarketing safety monitoring of drugs that can influence patterns of use and affect the composition of study populations include changing indications over time, time-varying exposures of long duration, the presence of a large number of potential confounding factors, and off-label use. The goal of this paper is to help those with an interest in regulatory science to develop and refine recommendations regarding which types of questions are most suitable for sequential surveillance and under what circumstances sequential surveillance will fit into the regulatory environment.