The Economic Burden of Herpes Zoster in Individuals Aged 50 Years or Older and Those With Underlying Conditions in Italy.

Background: Risk of herpes zoster (HZ) infection increases with age and immunosuppression. We estimated the impact of HZ and post-herpetic neuralgia (PHN) on direct costs and health care resource utilization (HCRU) in patients ≥50 years, including those with comorbidities, as limited information exists in Italy. Methods: This retrospective analysis used reimbursement data from local health authorities in Italy (January 2009-June 2022). Cases of HZ and PHN identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes and drug prescriptions were characterized and followed up for 1 year before and after the index date. The direct HCRU costs for patients with HZ/PHN were compared with those for patients without HZ/PHN. Results: Of the total 193 259 patients with HZ/PHN identified (mean age, 61.6 years), 145 923 were ≥50 years old (immunocompromised: 29.9%; ≥1 chronic condition: 76.1%). During follow-up, 18.8% of patients ≥50 years of age with HZ progressed to PHN complications, and 3618 hospital admissions were reported (median length of stay, 9 days). Drug prescriptions and all-cause hospitalizations were the main contributors to total annual direct health care costs, estimated at M€272 for patients with HZ/PHN, whose burden increased with age. Higher health care costs were observed in patients with HZ/PHN vs patients without HZ/PHN. Moreover, average health care costs were up to 4× higher for patients with HZ and PHN compared with those without PHN. Conclusions: HZ causes a significant economic impact on the health care system, driven mainly by high costs of medications and hospitalizations among older adults and those with comorbidities, particularly when complicated by PHN.