Using rates of non-adherence to identify opportunities for intervention in outpatient specialty clinics

Background: Adherence to specialty medications is crucial to achieve desired clinical outcomes. Approximately 30-50% of patients on chronic medications are reportedly non-adherent, with up to 50% of non-adherence being clinically appropriate. However, the patients who are non-adherent without clinical reason present an opportunity for the specialty pharmacies to improve adherence leading to optimal outcomes. Identifying disease states at highest risk for nonadherence within specialty populations will provide meaningful outcomes on which specialty pharmacists can focus targeted adherence efforts. Objectives: To utilize pharmacy claims data to determine and analyze rates of non-adherence in outpatient specialty clinics. Methods: This is a single-center, retrospective pharmacy claims analysis. Claims data for specialty medications at Vanderbilt Specialty Pharmacy (VSP) from November 2016 to December 2017 were used to calculate proportion of days covered (PDC). Clinical categories were assigned to patients in the dispensing system used at VSP, and included cystic fibrosis, dermatology, endocrinology, hepatitis C, idiopathic pulmonary fibrosis, infectious diseases, irritable bowel disease, lipid disorders, neurology, multiple sclerosis, oncology, pulmonary arterial hypertension, and rheumatology. Also included were pediatric categories. Patients were included if they received at least three fills from VSP. Nonadherence was defined as a PDC of