Preparing for a Safety Evaluation of Rotavirus Vaccine Using Health Services Data in Ontario: The Development of a Diagnostic Algorithm for Intussusception, an Estimation of Baseline Incidence and an Evaluation of Methods

In view of the recent implementation of a publicly funded rotavirus vaccination program in Ontario, we undertook studies to help guide the design of a safety evaluation of the vaccine with respect to intussusception. We used administrative data to develop and validate an algorithm for intussusception, and quantified its incidence in Ontario. We also conducted a systematic review of study designs used to evaluate post-licensure vaccine safety, and discussed each design’s strengths and weaknesses. The validated algorithm for intussusception was sensitive (89.3%) and highly specific (>99.9%). We observed the highest mean incidence (34 / 100,000) in males