Rheumatoid arthritis (RA), psoriatic arthritis (PsA) and psoriasis (PSO) are chronic inflammatory diseases that have a substantial impact on patients' health. This retrospective database study aimed to assess the epidemiology, comorbidities, diagnosis and treatment patterns of RA, PsA and PSO in the German population.
Data were extracted from the Deutsche Forschungsdatenbank für Abrechnungsinformationen der Krankenversicherung database from 2012 to 2016 for patients aged ≥ 18 years holding full health coverage in the reporting year at least. Diagnoses were defined according to International Classification of Diseases (ICD)-10 codes. Reported outcomes included prevalence and incidence rates, pre-defined comorbidities, diagnosing and treating physicians, and treatment exposure. A subgroup analysis was performed for women of childbearing age (females aged 18-45 years).
The prevalence rates of RA, PsA and PSO in Germany were consistent over the study period; by 2016 they were 0.4%, 0.3% and 2.1%, respectively, and in women of childbearing age they were 0.2%, 0.2% and 1.5%, respectively. RA, PsA and PSO were predominantly observed among patients aged > 45 years. RA and PsA were more prevalent in women, while PSO had an approximately equal gender distribution. Depressive episodes were the most frequently reported comorbidity in 2016 (RA: 25.7%; PsA: 25.1%; PSO: 17.8%), and this was similar in women of childbearing age (RA: 20.5%; PsA: 23.4%; PSO: 16.3%). Approximately 50% of patients with RA and PsA and 6% of patients with PSO were receiving systemic treatment in 2016, of which methotrexate (RA: 38.4%; PsA: 30.2%; PSO: 2.2%) was most common. Biologic therapies were the least frequently used treatment options (RA: 28.9%; PsA: 20.9%; PSO: 1.8%).
This analysis provides key epidemiological information for patients with RA, PsA and PSO, including in women of childbearing age, in Germany and highlights common comorbidities and that patients were likely receiving insufficient treatment for these diagnoses.