Importance of feasibility assessments before implementing non‐interventional pharmacoepidemiologic studies of vaccines: lessons learned and recommendations for future studies

PURPOSE Investigational and marketed vaccines are increasingly evaluated, and manufacturers are required to put in place mechanisms to monitor long-term benefit-risk profiles. However, generating such evidence in real-world settings remains challenging, especially when rare adverse events are assessed. Planning of an appropriate study design is key to conducting a valid study. The aim of this paper is to illustrate how feasibility assessments support the generation of robust pharmacoepidemiological data. METHODS Following an initiative launched by the International Society for Pharmacoepidemiology in May 2014, a working group including members of the private and public sectors, was formed to assess the value of conducting feasibility assessments as a necessary step before embarking on larger-scale post-licensure studies. Based on five real-life examples of feasibility assessments, lessons learned and recommendations were issued by the working group to support scientific reasoning and decision making when designing pharmacoepidemiologic vaccine studies. RESULTS The working group developed a toolbox to provide a pragmatic approach to conducting feasibility assessments. The toolbox contains two main components: the scientific feasibility and the operational feasibility. Both components comprise a series of specific questions aimed at overcoming methodological and operational challenges. CONCLUSIONS A feasibility assessment should be formalized as a necessary step prior to the actual start of any pharmacoepidemiologic study. It should remain a technical evaluation and not a hypothesis testing. The feasibility assessment report may facilitate communication with regulatory agencies toward improving the quality of study protocols and supporting the endorsement of study objectives and methods addressing regulatory commitments. © 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.