OBJECTIVES: To investigate the occurrence of Herpes Zoster (HZ) infections among high-risk patients. Additional purpose was to describe annual healthcare resource utilizations and related costs in the perspective of Italian Health System (IHS).

METHODS: Patients aged ≥50 in 2013, without HZ infection in the previous year and at high-risk (i.e. cardiovascular diseases, COPD, diabetes, immunodeficiency) were selected from ReS database, integrating reimbursed drug prescriptions, hospitalizations and specialist procedures data. Each subject was followed-up for 2 years to identify HZ occurrences, by hospitalization and brivudina prescription. Their healthcare resource utilizations and IHS direct costs were also provided.

RESULTS: Out of 12,562,609 beneficiaries, 1,004,705 (18.5%) HZ high-risk patients were selected (mean age 72±11; 52.5% males). During the two-year follow-up, 5,916 patients experienced the infection (incidence 5.9 x 1,000; higher among elderly, females and immunodepressed). In the 12 months post infection, these patients received brivudina (79.3%), aciclovir (4.5%), valaciclovir (3.1%) and famciclovir (0.6%), generating a mean cost/treated of 106€. Furthermore, the 26.3% of subjects was treated with a pain therapy (pregabalin, tramadol, gabapentin) with a mean cost/treated of 94€. In the same period, 8.0% of these subjects was admitted with a mean cost/hospitalized of 3,927€. Differences in resource utilization and costs were found among the clinical conditions considered as risk factors, with the highest values for immunodeficiency.

CONCLUSIONS: This real-world analysis provided annual incidence of HZ in high-risk subjects and the burden of this condition in the perspective of IHS. These findings can help the health governance to improve clinical and economic decisions concerning HZ vaccination plan.