Alopecia areata (AA) is an autoimmune disease that causes hair loss with subtypes alopecia totalis (AT) and alopecia universalis (AU), which result in complete loss of scalp and body hair, respectively. According to M. Ray and colleagues, AA research has calculated a 1.14% overall and 0.21% clinician-adjusted US point prevalence, as well as an incidence of 20 per 100,000 person-years (PY). However, they identified that data specific to AA and AU/AT in the US employer-sponsored insurance (ESI) population were not available. In their study, awarded a gold medal poster award at AMCP 2022, the researchers found that AA ESI prevalence was within clinician-adjusted estimates, but AA ESI incidence was higher.
Ray and the study’s collaborators further determined that “rates of AA and AT/AU were highest among females, adults, and in the Northeast,” and that AT and AU represented 5% to 10% of all AA cases.
These conclusions were based on a retrospective analysis of IBM MarketScan Commercial and Medicare claims databases, within which both prevalent and incident cases of AA, AU, and AT were identified from 2016 to 2019. Prevalence and incidence rates were calculated for the duration and stratified by age, sex, and region. National ESI population estimates were derived with American Community Survey population-based weights.
Overall, the prevalence of AA increased from 0.199% in 2016 to 0.212% in 2017, 0.219% in 2018, and 0.222% in 2019 (all p <0.001 vs. 2016). As noted, prevalence was higher in females (0.252%–0.271%) compared to males (0.145%–0.171%); in adults (0.220%–0.245%) compared to children (0.120%–0.135%); and in the Northeast (0.273%–0.305%) compared to other regions (0.155%–0.222%). Between 2016 and 2019, annual rates of AT/AU were 0.012%, 0.017%, 0.018%, and 0.019%, respectively, with similarly increased prevalence for female, adult, and Northeast patients. The incidence per 100,00 PY was 91.46 in 2016, 87.39 in 2017 (p <0.001), 91.31 in 2018 (p = 0.730), and 92.90 in 2019 (p <0.001). Dermatologists diagnosed 54% of incident cases, which were also more frequent in females, adults, and in the Northeast. The incidence of AU/AU was 8.92, 7.09, 7.30, and 7.92 per 100,000 PY from 2016–2019, respectively, and was also higher in the same three subsets.
In closing, the study’s authors urged that “further research is warranted to better understand subpopulation differences and trends in the broader US population.