Real-World Safety of Janus Kinase Inhibitors in Alopecia Areata: A Propensity Score-Matched Cohort Study of a Global Federated Health Network

Background/Objectives: Janus kinase inhibitors (JAKis) have transformed the treatment of alopecia areata (AA), but pivotal trials had short follow-ups and real-world long-term safety data remain scarce. We compared incident adverse outcomes between patients with AA exposed and not exposed to JAKis.

Methods

In this retrospective cohort study of the TriNetX Global Collaborative Network, adults (≥18 years) with ≥2 diagnoses of AA (ICD-10-CM L63) and ≥2 medication events for baricitinib, tofacitinib, ritlecitinib, or oral ruxolitinib were matched 1:1 by propensity score on demographics and 13 comorbidities to patients with AA and no recorded exposure to these agents. Cox models estimated hazard ratios (HRs); p values for the 19 estimable outcomes were adjusted using the Benjamini–Hochberg procedure (false discovery rate 5%), and E-values assessed unmeasured confounding. Drug-specific and eight sensitivity analyses were performed.