Incidence and prevalence of alopecia areata in the Australian primary care setting: A retrospective analysis of electronic health record data.

Abstract

Alopecia areata (AA) is a common immune-mediated non-scarring hair loss, with a worldwide incidence between 0.57% and 3.8%. The incidence and prevalence of AA in the Australian general population have not been previously reported. To describe the incidence and prevalence of AA in Australia using primary care data. A secondary objective was to identify common demographic characteristics, comorbidities and treatment patterns among Australians living with AA. We analysed electronic health record data captured from a national clinical practice management software over a 10-year index period between 2011 and 2020 calendar years, inclusive. The incidence of new-onset AA and the prevalence of active records with AA were estimated. Differences in incidence by sociodemographic groups, and patterns of treatment were also evaluated. There were 976 incident AA records. The incidence of new-onset AA in the total study cohort was 0.278 per 1000 person-years (95% CI 0.26-0.295). By age, the incidence was highest in the 19- to 34-year-old age bracket (0.503 per 1000 person-years: 95% CI 0.453-0.554). AA incidence was lower among females than males (IRR 0.763, p < 0.001, 95% CI 0.673-0.865). Among active records, 520 were prevalent AA records. AA point prevalence at 31/12/2020 was 0.13% (1.26 per 1000 persons; 95% CI 1.15-1.37). This is the first study to describe the epidemiology (incidence and point prevalence) and management of AA in the Australian primary health-care population through large-scale database analysis. Incidence and prevalence findings were consistent with earlier estimates from other regions.