Herpes Zoster-Attributable Resource Utilization and Cost Burden in Patients With Solid Organ Transplant

OBJECTIVES: To evaluate health-care utilization and costs attributable to herpes zoster (HZ) within a population of patients with solid organ transplant (SOT). METHODS: Using administrative claims data, a commercially/Medicare-insured population of patients with SOT between January 1, 1999, and January 1, 2007, and a Medicaid population between January 1, 1999, and January 1, 2006, were identified. Each patient group was screened to select patients with claims of SOT with an incident diagnosis of HZ and continuous enrollment for the 6 months prior and 3 months subsequent to the incident HZ. Controls were selected from group of SOT patients without claims of HZ using a propensity score matching process. Descriptive analyses were performed to quantify health-care utilization and costs attributable to HZ. Multivariate analyses were used to estimate HZ-attributable costs adjusted by demographic and clinical variables. RESULTS: A total of 205 commercially/Medicare-insured matched pairs and 136 Medicaid matched pairs were selected. Mean age in the commercial/Medicare SOT-HZ population was 56.9 years, and that in the Medicaid population was 42.5 years. The majority of HZ patients were diagnosed within 2 years of evidence of SOT. The unadjusted differences in total HZ-attributable health-care costs were $4762 and $6705 for commercial/Medicare-insured and Medicaid patients, respectively (P=0.176 and P=0.003, respectively) and were largely driven by hospitalization costs. Adjusted incremental costs in the SOT-HZ commercial/Medicare-insured patients were $5335 (P<0.001), and that in noncapitated Medicaid patients were $3711 (P<0.001). CONCLUSION: The occurrence of HZ in patients immunocompromised by SOT significantly increased health-care utilization and costs.