Interrupted Time Series (ITS) Studies in Systematic Reviews: Identification, Reporting and Bias

An interrupted time series (ITS) study is a type of non-randomised study that examines the effects of interventions when randomisation is not feasible, such as national policies. For ITS studies to be included in systematic reviews that inform policies and clinical guidelines, systematic reviewers require a validated search filter to retrieve ITS studies from bibliographic databases, and knowledge of whether evidence from the ITS literature is affected by reporting biases, incomplete reporting, and deviations from the analysis plan. This thesis addresses these methodological gaps, and provides recommendations for ITS researchers and systematic reviewers who use evidence from ITS studies.