Objectives: Suboptimal compliance and failure to persist with antidiabetes therapies are of potential economic significance. The present research aims to describe the impact of poor compliance and persistence with antidiabetes medications on the cost of healthcare or its components for patients with type 2 diabetes mellitus (T2DM).
Methods: Literature search was conducted in PubMed for relevant articles published in the period between 1 January 2000 and 30 April 2009. Thus, it is possible that relevant articles not listed in PubMed, but available in other databases are not included in the current review. Studies describing economic consequence of compliance and/or persistence with pharmaceutical antidiabetes treatment were identified. The variability in the studies reviewed was high, making it extremely difficult to make a comparison between them.
Results: Of 449 articles corresponding to the primary search algorithm, 12 studies (all conducted in USA) fulfilled the inclusion criteria regarding the economic impact of compliance and/or persistence with treatment on the overall cost of T2DM care or its components. Compliance was assessed via medication possession ratio (MPR) in ten studies, where it ranged from 0.52 to 0.93 depending on regimen. Persistence was assessed in one study. Mean total annual costs per T2DM patient varied between the studies, ranging from $4570 to $17338. In seven studies, medication compliance was inversely associated with total healthcare costs, while in four other studies inverse associations between medication compliance and hospitalisation costs were reported. In one study increased adherence did not change overall healthcare costs.
Conclusions: Improved compliance may lead to reductions of the total healthcare costs in T2DM, Further research is needed in countries other than the US to assess impact of compliance and persistence to pharmacotherapy on T2DM costs in country-specific settings.