How Should We Deal with Patient Heterogeneity in Economic Evaluation: A Systematic Review of National Pharmacoeconomic Guidelines

ObjectiveTo review and analyze recommendations from national pharmacoeconomic guidelines with regard to acknowledging patient heterogeneity in economic evaluations.MethodsNational pharmacoeconomic guidelines were obtained through the ISPOR Web site. Guidance was extracted by using a developed data extraction sheet. Extracted data were divided into subcategories on the basis of consensus meetings.ResultsOf the 26 included guidelines, 20 (77%) advised to identify patient heterogeneity. Most guidelines (77%) provided general methodological advice to acknowledge patient heterogeneity, including justifications for distinguishing subgroups (65%), prespecification of subgroups (42%), or methodology to acknowledge patient heterogeneity (77%). Stratified analysis of cost-effectiveness was most commonly advised (20 guidelines; 77%); however, guidance on the specific application of methods was scarce (9 guidelines; 34%) and generally limited if provided. Guidance to present patient heterogeneity was provided by 15 guidelines (58%), most prominently to describe the definition (31%) and justification (31%) of subgroups.ConclusionsThe majority of national pharmacoeconomic guidelines provide guidance on acknowledging patient heterogeneity in economic evaluations. However, because guidance is mostly not specific, its usefulness is limited. This may reflect that the importance of acknowledging patient heterogeneity is usually recognized while there is a lack of consensus on specific methods to acknowledge patient heterogeneity. We advise the further development of national pharmacoeconomic guidelines to provide specific guidance on the identification of patient heterogeneity, methods to acknowledge it, and presenting the results. We present a checklist that can assist in formulating these recommendations. This could facilitate the systematic and transparent handling of patient heterogeneity in economic evaluations worldwide.