Risk factors for herpes zoster in a large cohort of unvaccinated older adults: a prospective cohort study

Abstract

SUMMARY We analysed data from a prospective cohort of 255024 adults aged ⩾45 years recruited from 2006-2009 to identify characteristics associated with a zoster diagnosis. Diagnoses were identified by linkage to pharmaceutical treatment and hospitalization records specific for zoster and hazard ratios were estimated. Over 940583 person-years, 7771 participants had a zoster diagnosis; 253 (3·3%) were hospitalized. After adjusting for age and other factors, characteristics associated with zoster diagnoses included: having a recent immunosuppressive condition [adjusted hazard ratio (aHR) 1·58, 95% confidence interval (CI) 1·32-1·88], female sex (aHR 1·36, 95% CI 1·30-1·43), recent cancer diagnosis (aHR 1·35, 95% CI 1·24-1·46), and severe physical limitation vs. none (aHR 1·33, 95% CI 1·23-1·43). The relative risk of hospitalization for zoster was higher for those with an immunosuppressive condition (aHR 3·78, 95% CI 2·18-6·55), those with cancer (aHR 1·78, 95% CI 1·24-2·56) or with severe physical limitations (aHR 2·50, 95% CI 1·56-4·01). The novel finding of an increased risk of zoster diagnoses and hospitalizations in those with physical limitations should prompt evaluation of the use of zoster vaccine in this population. Show more