PSY91 - Poor Medication Adherence and High Rates of Treatment Discontinuation Among SCD Patients Treated with Hydroxyurea

Abstract

To examine the treatment patterns of sickle cell disease (SCD) patients prescribed hydroxyurea (HU). A retrospective study was conducted using the Medicaid Analytic Extracts database from 2009-2013. Patients with at least one pharmacy claim for HU were identified and the first observed HU claim date during the identification period was designated as the index date. Patients were required to have a SCD diagnosis (ICD-9-CM: 282.41-282.42, 282.60-282.69) prior to the index date and continuous Medicaid enrollment for at least a 6-month pre- (baseline) and 12-month post-index (follow-up) period. Treatment patterns including discontinuation, time-to-discontinuation, re-initiation, medication possession ratio (MPR), and concomitant SCD therapies were examined. All variables were analyzed descriptively. A total of 3,999 patients met the study inclusion criteria. The mean age of SCD patients prescribed HU was 19.2 years. Most patients were black (73.3%), and the mean Charlson comorbidity index score was 0.6. The most prevalent comorbid conditions were fever (31.4%), asthma (20.3%), and infectious and parasitic disease (20.0%). 53.6% of the HU patients had an inpatient pain crisis during the baseline period. During the 12-month follow-up period, 58.9% (N=2,357) of the patients discontinued HU medication, with an average time to HU discontinuation of 202.4 days (Standard Deviation=143.5 days). Furthermore, 52.5% (N=1,237) of those patients reinitiated HU after discontinuation during the 12-month follow-up period. Only 22.3% of the study population had MPR ≥80%, and antibiotics was the most prescribed concomitant medication (77.8%) during the follow-up period. SCD patients treated with HU have a significant unmet need in terms of poor medication adherence and high rates of treatment discontinuation. Future research is needed to evaluate the reasons for discontinuation in a real-world data set and develop disease management strategies to alleviate the burden.