Method: Patients with a claim for AA were identified in the TRUVEN Commercial Claims and Encounters and Medicare Supplemental datasets. The study population had continuous medical and pharmacy eligibility 6 months prior to and 6 months after their first AA claim (index), at least one pre-index and one post-index diagnosis for PC (ICD-9 185.xx) and metastasis (ICD-9 196.XX-199.XX) 6 months prior to or on and 6 months after the AA index date. Patients were categorized by evidence of recent chemotherapy (RC) within 6 months of the AA index date or no evidence of chemotherapy within 6 months of the AA index date. AA and P utilization metrics included total mean and median daily dose and refill consistency. Refill consistency was calculated for patients with ≥2 AA prescriptions and defined as the sum of the days supply between first and last fill dates divided by the total days between first and last fill dates. Data were summarized with descriptive statistics (e.g., n,% mean, SD, median, etc).
Result: A total of 515 AA-treated patients were included; 258 with recent chemotherapy (RC) and 257 with no recent chemotherapy (NC) in the prior 6 months. Mean age was 71 years (RC) and 74 years (NC). The mean±SD AA daily dose was 998.2±21.7mg (1,000 mg; median) for the RC group and 999.5±34.8 mg (1,000 mg; median) for the NC group. AA refill consistency for RC and NC groups indicated AA was available for over 90% of days between first and last prescription dates. P use was observed in 93.4% of RC and 96.5% of NC patient. The mean ±SD daily P dose was 10.1±2.7 mg (10 mg; median) for RC and 10.1 ± 2.1 mg (10 mg; median) for NC.
Conclusion: This retrospective analysis suggests that mCRPC patients demonstrate a high level of compliance with AA and P as recommended in the AA product label.
1Abiraterone Acetate (Zytiga®) Prescribing Information; December 2012