Adherence to Insulin Pen Therapy Is Associated with Reduction in Healthcare Costs Among Patients with Type 2 Diabetes Mellitus.

Diabetes mellitus is a chronic metabolic disorder posing a significant economic burden on the US healthcare system. According to the American Diabetes Association, an estimated 22.3 million people in the United States were diagnosed with diabetes in 2012, representing approximately 7% of the population.1 The prevalence of diabetes increased by 23% from 2007 to 2012 and is projected to increase to 1 in 3 adults by 2050.1 In 2012, the total estimated cost of diagnosed diabetes was $245 billion, including $176 billion in direct medical costs and $69 billion in lost productivity.1 The most common long-term complications of diabetes mellitus are retinopathy, with a potential loss of vision; nephropathy leading to renal failure; peripheral neuropathy, which is associated with the risk for foot ulcers and amputation; and cardiovascular-related morbidity and mortality.2 Patients with diabetes often progress toward numerous metabolic abnormalities, leading to a high risk for cardiovascular-related morbidity and mortality, with greater disease severity associated with higher risk.3 Diabetes is classified into type 1, type 2, and gestational disease. Type 1 diabetes accounts for approximately 5% to 10% of all cases of diabetes in the United States, whereas type 2 diabetes accounts for 90% to 95% of all cases.2 Glycemic control is crucial for preventing or minimizing the long-term complications associated with diabetes. To achieve and maintain optimal glycemic control, type 1 diabetes is generally managed through lifestyle changes. Similarly, type 2 diabetes management may also require lifestyle changes (including diet), but the disease may progress to require a combination of oral medications, noninsulin injectables, and/or insulin therapy in addition to lifestyle changes.4 The American College of Endocrinology (ACE) and American Association of Clinical Endocrinologists (AACE) suggest lifestyle management for all phases of type 2 diabetes, intensifying at higher hemoglobin (Hb) A1c levels. The ACE/AACE guidelines also recommend initiating oral antidiabetic medications when the HbA1c level is between 6% and 7%, and adding insulin therapy when the HbA1c level exceeds 8% among therapy-naive patients, typically beginning with basal (ie, long-acting) insulin, and adding bolus (ie, short-acting) insulin if further intervention is needed.4 Because of the substantial human and economic burdens of type 2 diabetes, there is interest in understanding real-world patient adherence to, and persistence with, insulin therapy in this patient population; adherence measures the use of a medication as directed during treatment, and persistence measures treatment duration.5 Previous research has described poor adherence to oral medications and to insulin therapy.6 Similarly, insulin persistence is low, ranging from 26% to 52% in the year after the initiation of basal insulin, and even lower, at 19% to 42%, for bolus insulin.7 Recent research suggests that patients with type 2 diabetes who start therapy or are converted to insulin therapy with a pen demonstrate comparable or improved medication adherence versus patients who receive insulin with a vial or syringe.8–10 Health resource utilization, based on claims for hypoglycemic events, emergency department visits, physician visits, and annual medication costs, was found to be lower in patients using insulin pens.8–10 Compared with syringes, insulin pen devices have been shown to provide more reliable, accurate, and simplified dosing.11–13 KEY POINTS ▸ Type 2 diabetes mellitus carries a major economic burden stemming from direct and indirect medical costs, loss of productivity, and premature mortality. ▸ This retrospective claims-based analysis investigated whether improved adherence to insulin pen therapy could mitigate healthcare costs in patients with type 2 diabetes. ▸ The average annual per-patient healthcare expenditures in the least adherent cohort was 1.53 times higher ($27,707) than in the most adherent group of patients ($18,068). ▸ In the postindex period, the total all-cause expenditures were significantly (P = .007) lower for the most adherent group ($23,839) versus the least adherent group ($26,310). ▸ Patients with the greatest insulin adherence had almost double the overall pharmacy costs compared with patients with the lowest adherence ($10,174 vs $5395, respectively; P <.001). ▸ According to this real-world pharmacy and medical analysis, the total healthcare cost of patients with type 2 diabetes who used insulin pens decreased with improvement in adherence. ▸ More research is needed to characterize the exact relationship between insulin adherence and healthcare costs. Insulin delivery systems other than a vial or a syringe have the potential to improve factors such as patient treatment satisfaction, treatment adherence, and clinical outcomes.9 The use of these systems, such as prefilled insulin pens, in the United States has lagged behind other countries.9 The substantial and growing burden of type 2 diabetes and opportunities to curb its associated costs have been the focus of policymakers, payers, and nonprofit organizations. Strategies to improve medication adherence and its potential to lower healthcare resource utilization and costs for patients with type 2 diabetes are of interest to a wide variety of stakeholders.14,15 Consequently, there is significant interest in understanding the association between insulin adherence and healthcare costs for patients with type 2 diabetes who are insulin pen users. The objectives of this study were to determine if higher insulin pen adherence among patients with type 2 diabetes who are insulin pen users was associated with lower healthcare costs, and to describe the overall healthcare costs of patients with type 2 diabetes. This study may provide insights to payers and providers to guide future analyses in identifying ways to improve diabetes care outcomes and to lower the associated healthcare expenditures.16