Real-World Assessment of Disease Characteristics and Clinical Outcomes in Alopecia Areata in a Global Noninterventional Observational Cohort (ADAAGIO)

Background: A range of medications with varying efficacy are used to treat alopecia areata (AA). There remains limited evidence on prevailing treatments, disease characteristics, and clinical outcomes of patients with AA in routine practice, particularly for those with extensive hair loss. This study sought to address this evidence gap. Methods: This was a retrospective chart review study spanning the United Kingdom, France, Spain, and Germany. Adult and adolescent patients with ≥50% scalp hair loss were included. The study index date was defined as date of de novo or progression to ≥50% scalp hair loss and patients were required to have ≥6 months of postindex follow-up (i.e., index date to last clinic visit); index dates ranged 2015-2019. Analyses were descriptive and reported patient demographics, baseline clinical characteristics, and Dermatologic Life Quality Index (DLQI) score. The primary clinical endpoint was absolute Severity of Alopecia Tool (SALT) score and was assessed longitudinally based on post-index visits in which SALT was recorded. Sustained SALT ≤20 was also assessed via Kaplan-Meier methods to evaluate time to achieving SALT ≤20 without subsequent regression within 6 months to SALT >30. Results: A total of 741 patients were included. Median age at AA diagnosis was 27 years and 52.6% were female. Mean (SD) baseline SALT score at index was 63.5 (15.6), with 80.2% having patchy AA and 19.8% having alopecia totalis or universalis. Among patients with DLQI measured at index, mean (SD) DLQI score was 19.2 (7.2) with 84.5% reporting either a large (DLQI 11-20) or extremely large (DLQI 21-30) impact of AA. Topical corticosteroids were the most common treatment observed post-index, with 55.6% receiving ≥1 course with a median cumulative exposure of 4 months. Intralesional corticosteroids (22.5%), systemic immunosuppressants (22.0%), and oral (17.3%) or topical (19.4%) minoxidil were also common. Among patients with SALT measured at 12 months post-index, there was a mean (SD) absolute SALT reduction of -44.6% (37.3%) from baseline. However, at 12 months post-index, most patients (90.1%) failed to achieve SALT ≤20 that was sustained for ≥6 months. Conclusions: Although patients in this study experienced a substantial absolute SALT score reduction, few patients achieved and subsequentially sustained the more clinically meaningful SALT threshold of ≤20. These findings highlight the potential suboptimal effectiveness of the varied treatments applied in this population.