Jennifer E Mason1, Darin A England2, Brian T Denton1, Steven A Smith3, Murat Kurt4, Nilay D Shah3. 1. Edward P. Fitts Department of Industrial & Systems Engineering, North Carolina State University, Raleigh, North Carolina (JEM, BTD) 2. Ingenix, Eden Prairie, Minnesota (DAE) 3. Division of Endocrinology, Diabetes, Nutrition, & Metabolism and Division of Health Care Policy & Research, Knowledge and Encounter Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota (SAS, NDS) 4. Industrial Engineering Department, University of Pittsburgh, Pittsburgh, Pennsylvania (MK)
Abstract
BACKGROUND: Statins are an important part of the treatment plan for patients with type 2 diabetes. However, patients who are prescribed statins often take less than the prescribed amount or stop taking the drug altogether. This suboptimal adherence may decrease the benefit of statin initiation. OBJECTIVE: To estimate the influence of adherence on the optimal timing of statin initiation for patients with type 2 diabetes. METHOD: The authors use a Markov decision process (MDP) model to optimize the treatment decision for patients with type 2 diabetes. Their model incorporates a Markov model linking adherence to treatment effectiveness and long-term health outcomes. They determine the optimal time of statin initiation that minimizes expected costs and maximizes expected quality-adjusted life years (QALYs). RESULTS: In the long run, approximately 25% of patients remain highly adherent to statins. Based on the MDP model, generic statins lower costs in men and result in a small increase in costs in women relative to no treatment. Patients are able to noticeably increase their expected QALYs by 0.5 to 2 years depending on the level of adherence. CONCLUSIONS: Adherence-improving interventions can increase expected QALYs by as much as 1.5 years. Given suboptimal adherence to statins, it is optimal to delay the start time for statins; however, changing the start time alone does not lead to significant changes in costs or QALYs.
BACKGROUND: Statins are an important part of the treatment plan for patients with type 2 diabetes. However, patients who are prescribed statins often take less than the prescribed amount or stop taking the drug altogether. This suboptimal adherence may decrease the benefit of statin initiation. OBJECTIVE: To estimate the influence of adherence on the optimal timing of statin initiation for patients with type 2 diabetes. METHOD: The authors use a Markov decision process (MDP) model to optimize the treatment decision for patients with type 2 diabetes. Their model incorporates a Markov model linking adherence to treatment effectiveness and long-term health outcomes. They determine the optimal time of statin initiation that minimizes expected costs and maximizes expected quality-adjusted life years (QALYs). RESULTS: In the long run, approximately 25% of patients remain highly adherent to statins. Based on the MDP model, generic statins lower costs in men and result in a small increase in costs in women relative to no treatment. Patients are able to noticeably increase their expected QALYs by 0.5 to 2 years depending on the level of adherence. CONCLUSIONS: Adherence-improving interventions can increase expected QALYs by as much as 1.5 years. Given suboptimal adherence to statins, it is optimal to delay the start time for statins; however, changing the start time alone does not lead to significant changes in costs or QALYs.