P30: Prevalence and treatment patterns of adult atopic dermatitis in the UK Clinical Practice Research Datalink

E. Kleyn,¹ B. Gittens,² A. Meeks³ and L.-B. von Arx⁴

¹The Dermatology Centre, The University of Manchester, Manchester, UK; ²Eli Lilly and Company, Basingstoke, UK; ³Eli Lilly and Company, Indianapolis, IN, USA; and ⁴Eli Lilly and Company, Copenhagen, Denmark

Atopic dermatitis (AD) is a common chronic, relapsing skin disorder that can persist from childhood or present in adults. AD imposes a high burden of disease on those affected and the impact on the UK adult population is not well characterized. This noninterventional registry-based study aimed to interrogate UK Clinical Practice Research Datalink (CPRD) data on the prevalence, patient characteristics and treatment patterns of adults with active AD. Data covering the period 1 January 2015 to 1 January 2020 were obtained from the CPRD. An established algorithm based on diagnosis code and pharmaceutical treatment identified adult (age ≥ 18 years) patients with AD. Patients with active AD were identified by an AD-related prescription or physician visit in the past 12 months. Prevalence was calculated as the number of patients meeting the criteria for active AD on the 1 January of each year (2016–20) divided by the number of adults in the CPRD population on that date. Moderate-to-severe disease was classified by referral to a specialist (dermatology or immunopathology) or a prescription for topical calcineurin inhibitors, systemic treatment or phototherapy. Data were analysed using descriptive statistics. As per 1 January 2020, 64 933 of 2 616 192 adults had active AD, corresponding to a prevalence rate of 2·5%. The prevalence of active AD on 1 January in each of the years 2016–18 was 2·5%; in 2019 it was 2·6%. The percentage of patients with active AD meeting the criteria for moderate-to-severe disease in each consecutive year (2016–20) was 7·5%, 7·7%, 7·7%, 7·9% and 8·3%, respectively. As of 1 January 2020, 58·4% of patients with active AD were female, mean (SD) body mass index was 29·2 (6·9), and mean (SD) duration of disease was 9·4 (5·9) years. In the population of patients with moderate-to-severe AD, 2030 patients were treated with a systemic agent (methotrexate, azathioprine, mycophenolate mofetil, ciclosporin, methotrexate sodium, mycophenolate sodium, dupilumab) in 2019 [mean (SD) of 7·7 (5·0) prescriptions per patient], 1258 were prescribed an oral glucocorticoid [mean (SD) of 4·0 (4·5) per patient] and 3977 patients received topical treatment [mean (SD) of 4·2 (4·5) prescriptions per patient]. In total, 2279 were referred to a specialist (dermatology or immunopathology) with a mean (SD) of 8·3 (6·2) years between diagnosis to referral. The prevalence of active AD in the adult UK population was stable over the last 5-year period (2015–19) and was comparable to estimates from similar studies based in UK primary healthcare records settings.