Abstract
Using national registers, this study investigates regional variations in the number of individuals with and treatment of atopic dermatitis (AD) in Denmark. AD, a prevalent chronic skin disorder, affects up to 20% of children and 3% of adults globally; yet its epidemiology in Denmark remains unclear. A recent study indicated a lifetime prevalence of 21% among school-aged children in Odense, a medium-sized city in Denmark, highlighting the long-lasting nature of the condition. With advancements in machine learning, researchers can now identify AD cases in both adults and children through healthcare utilization data. While Denmark's single-payer system aims to provide equitable access to healthcare, factors such as decentralized administration and patient choice can lead to regional variations in the treatment setup. The study spans from 1995 to 2020, revealing an overall identification of 537,001 individuals with AD. Results demonstrate consistent regional variations, with the Central Denmark Region exhibiting the highest recorded rates over 11 out of 14 years. There are also notable differences in advanced treatment rates and hospital consultations among regions. Thus, regional variation was observed, and to reduce unwarranted regional variation it is important to minimize diagnostic uncertainty and provide.