A checklist for retrospective database studies - Report of the ISPOR task force on retrospective databases

Introduction: Health-related retrospective databases, in particular claims databases, continue to be an important data source for outcomes research. However, retrospective databases pose a series of methodological challenges, some of which are unique to this data source. Methods: In an effort to assist decision makers in evaluating the quality of published studies that use health-related retrospective databases, a checklist was developed that focuses on issues that are unique to database studies or are particularly problematic in database research. This checklist was developed primarily for the commonly used medical claims or encounter-based databases but could potentially be used to assess retrospective studies that employ other types of databases, such as disease registries and national survey data. Results: Written in the form of 27 questions, the checklist can be used to guide decision makers as they consider the database, the study methodology, and the study conclusions. Checklist questions cover a wide range of issues, including relevance, reliability and validity, data linkages, eligibility determination, research design, treatment effects, sample selection, censoring, variable definitions, resource valuation, statistical analysis, generalizability, and data interpretation. Conclusions: For many of the questions, key references are provided as a resource for those who want to further examine a particular issue.