OBJECTIVES: This study aimed to characterize the inpatient burden associated with herpes zoster (HZ) with/without complications in mainland Portugal, as well as their costs.

METHODS: We conducted a retrospective study based on secondary healthcare data collected from 01/01/2017 to 31/12/2017 in the Portuguese Hospital Morbidity Database. The aim was to characterize hospitalized adult patients (≥18 years) with a primary diagnosis of HZ with/without complications, and their inpatient episodes. Each hospitalization episode cost was calculated considering the diagnosis-related group funding values for 2018 defined by order No. 254/2018. Subgroup analyses were performed for patients aged ≥50 years and for immunocompromised (IC) adults aged ≥18 years.

RESULTS: A total of 189 patients (47% male, mean age: 69 years) had an HZ episode with/without complications as primary diagnosis in 2017 in Portugal. This resulted in 191 hospitalizations, with a mean length of hospital stay of 14 days. IC ≥18-year-old patients represented ~20% of patients at primary diagnosis. The mean length of hospital stay for ≥50-year-old patients (131 hospitalizations) was 15 days, representing HZ hospitalization costs of €448,346.31. Among all patients hospitalized for HZ, 71% developed complication(s): post-herpetic neuralgia (14% out of all patients), zoster encephalitis (12%), zoster meningitis (11%), and zoster ocular disease (11%). The mean length of hospital stay was longer in ≥50-year-old patients with at least one complication (92 hospitalizations) when compared with those without complications (39 hospitalizations): 17 versus 10 days. This resulted in average HZ hospitalization costs per patient of €3,877.41 and €2,349.36 among ≥50-year-old patients with and without HZ complications, respectively. Overall, direct costs associated with HZ hospitalizations were €554,824.95 in 2017.

CONCLUSIONS: This study allowed characterizing HZ hospitalizations in Portugal, evidencing longer stay for older patients and for patients who had HZ complications. The annual economic burden related to HZ hospitalizations exceeds half a million euros.