Incidence and prevalence of alopecia areata in the Australian primary care setting: A retrospective analysis of electronic health record data
Rodney Sinclair, Samantha Eisman, Wei Song, Brandon Heung, C. Surian, Chia‐Wei Lee, David Witcombe
Abstract
BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.