OBJECTIVES

: Incidence of herpes zoster (HZ) increases with age, and is also higher in individuals with immunocompromised (IC) conditions including human immunodeficiency virus, steroid therapy and solid organ transplantation. Reported estimates of HZ incidence are limited to assessment in either healthy or IC populations. Hence if these values are used to represent the general population, HZ burden of disease may be under- or overestimated. We aimed to estimate HZ incidence in the general population by applying a weighting method.

METHODS

: Data were sourced from the UK Clinical Practice Research Datalink which generated HZ incidence in selected IC and IC-free populations over 12 years. The prevalence of IC conditions was assessed by age group (50-59, 60-64, 65-69, 70-79, ≥80 years of age [YOA]) and increased with age, ranging from 16.1% to 42.2% in individuals 50-59 and ≥80 YOA, respectively. These values were used to weight HZ incidence by IC status and generate HZ incidence estimates in the general population.

RESULTS

: Incidence of HZ was higher in the IC population, ranging from 6.9/1000 to 12.6/1000 in individuals 50-59 and ≥80 YOA, respectively, compared with the IC-free population, which range from 4.9/1000 to 11.0/1000 in the 50-59 and ≥80 YOA groups, respectively.

Weighting with prevalence of IC conditions by age group resulted in HZ incidence values in the overall population ranging from 5.2/1000 to 11.6 in the 50-59 and ≥80 YOA groups, respectively.

CONCLUSIONS

: For accurate and robust estimates of HZ- incidence in the general population, it is important to account for the values in both the IC and IC-free populations by weighting HZ incidence with prevalence of IC conditions and age. This method should also be applied to other burden of disease parameters such as the percentage of subjects with postherpetic neuralgia (PHN) and other non-PHN complications.