Herpes zoster and postherpetic neuralgia in Catalonia (Spain) Epidemiology and costs in persons aged 50 years and older

The objective of the study was to analyze the descriptive epidemiology and costs of herpes zoster (HZ) and postherpetic neuralgia (PHN) in people aged 50 years in Catalonia (Spain). The incidence of HZ in Catalonia was estimated by extrapolating the incidence data from Navarre (Spain) to the population of Catalonia. The incidence of PHN was estimated according to the proportion of cases of HZ in the case series of the Hospital del Sagrado Corazon de Barcelona that evolved to PHN. Drug costs were obtained directly from the prescriptions included in the medical record (according to official prices published by the General Council of the College of Pharmacists). The cost of care was obtained by applying the tariffs of the Catalan Health Institute to the number of outpatient visits and the number and duration of hospital admissions. The estimated annual incidence of HZ was 31763, of which 21532 (67.79%) were in patients aged 50 years. The respective figures for PHN were 3194 and 3085 (96.59) per annum, respectively. The mean cost per patient was markedly higher in cases of PHN (916.66 euros per patient) than in cases of HZ alone (301.52 euros per patient). The cost increased with age in both groups of patients. The estimated total annual cost of HZ and its complications in Catalonia was Euro 9.31 million, of which 6.54 corresponded to HZ and 2.77 to PHN. This is the first Spanish study of the disease burden of HZ in which epidemiological data and costs were collected directly from medical records. The estimated incidence of HZ is probably similar to the real incidence. In contrast, the incidence of PHN may be an underestimate, as around 25% of patients in Catalonia attend private clinics financed by insurance companies. It is also probable that the costs may be an underestimate as the costs derived from the prodromal phase were not included. In Catalonia, HZ and PHN cause an important disease burden (21532 cases of HZ and 3085 de PHN with an annual cost of Euro 9.31 million) in people aged 50 years, in whom vaccination is indicated.