The impact of non-compliance with imatinib (IM) therapy on health care costs

Abstract

6083 Background: While compliance to drug therapy is vital to receive optimal patient benefits, the costs of delivering adequate medical care for cancer patients remain an important consideration for society and payers. This study examined the relationship between compliance with IM therapy and health care costs for patients with CML and GIST. Methods: Claims data from 6/1/01–3/31/04 from a US health plan were used to identify non-Medicare IM-treated patients with a CML or GIST diagnosis who had continuous pharmacy and medical benefits in the 3 months prior and 12 months following initiation of IM therapy. Compliance was defined by medication possession ratio (MPR=total days IM supply in the first year ÷365) and patients were stratified into three segments by MPR (<50%, 50–90%, 90–100%). Total health care costs include hospital, laboratory testing, office, ER, and pharmacy charges. Disease-related health care costs were also analyzed. Multivariate analyses were used to examine the relationship between MPR and first-year health care costs, controlling for age, sex, number of medications, initial starting dose, diagnosis (CML or GIST), year of initial IM fill, and complications due to underlying disease. Results: Total 878 IM-treated patients were identified of whom 413 had at least 15 months of continuous eligibility. Of these, 307 were non-Medicare CML or GIST patients. Total health care costs per patient in the first year of therapy in MPR < 50%, 50–90%, and 90–100% groups were $163,828, $53,924, and $40,924 respectively (p < 0.001). The corresponding numbers for disease-related health care costs were $103,118, $36,436, and $34,086 (p<0.001). Controlling for the variables listed above, a 10% increase in MPR is associated with a 5% decrease in total health care costs (p=0.021). Similar association was found between MPR and disease-related health care costs. Conclusions: Improved compliance with imatinib therapy is associated with decreased total health care costs and disease-related health care costs. Improving compliance to imatinib therapy may not only optimize clinical outcomes but may also reduce the overall societal burden of health care costs associated with cancer. [Table: see text]