The overall purpose of the study is to provide an estimate of the cumulative lifetime incidence of AA in the population overall and by important sociodemographic groups. Moreover, to do a subgroup analysis in the AA population to identify health-related disparities across people in different socioeconomic strata, geographical distribution, sex and ethnic groups. The disparities that will be considered are AA associated: Mental health conditions; healthcare utilisation; and work impact (time off work and unemployment).~The cumulative lifetime risk of AA was estimated at age 80 years (approximate life expectancy in the UK) using survival models, with age as the timescale and accounting for the competing risk of death.~The assessment of any associations with baseline characteristics and the outcomes of interest will be assessed using Cox proportional hazards models (time to event outcomes) and Poisson regression (repeated event outcomes) models.
Alopecia areata (AA) is a common immune-mediated non-scarring alopecia often associated with substantial morbidity. There are however, limited population-based data on potential disparities in the burden of AA, including across people of different ethnicities and deprivation.~We aimed to provide the first large-scale, population-based estimate of lifetime risk of AA overall and by important sociodemographic subgroups. As AA is associated with an increased burden of mental health conditions and work-related outcomes (unemployment, time off work), a detailed understanding of the burden of disease in different sociodemographic groups is vital to plan resource provision.