Unwarranted clinical variation in health care: Definitions and proposal of an analytic framework

RATIONALE, AIMS, AND OBJECTIVES: Unwarranted clinical variation is a topic of heightened interest in health care systems around the world. While there are many publications and reports on clinical variation, few studies are conceptually grounded in a theoretical model. This study describes the empirical foundations of the field and proposes an analytic framework. METHOD: Structured construct mapping of published empirical studies which explicitly address unwarranted clinical variation. RESULTS: A total of 190 studies were classified in terms of three key dimensions: perspective (assessing variation across geographical areas or across providers); criteria for assessment (measuring absolute variation against a standard, or relative variation within a comparator group); and object of analysis (using process, structure/resource, or outcome metrics). CONCLUSION: Consideration of the results of the mapping exercise—together with a review of adjustment, explanatory and stratification variables, and the factors associated with residual variation—informed the development of an analytic framework. This framework highlights the role that agency and motivation, evidence and judgement, and personal and organizational capacity play in clinical decision making and reveals key facets that distinguish warranted from unwarranted clinical variation. From a measurement perspective, it underlines the need for careful consideration of attribution, aggregation, models of care, and temporality in any assessment.