Epidemiologic study of patients with psoriatic arthritis in a real-world analysis: a cohort study of the French health insurance database

Objective: PsA is a chronic inflammatory arthritis with heterogeneous disease manifestations. Data on the prevalence of PsA in adults differ widely depending on the study and the country. This study aimed to estimate the prevalence and incidence of PsA in France, characterize comorbidities associated to PsA and identify prescribed treatments. Methods: This nationwide cohort study involved the administrative healthcare database (Systeme National des Donnees de Sante) of the French health insurance scheme linked to the national hospital discharge database. All adults with PsA registered in the database and identified with a specific International Classification of Diseases, 10th revision code (M07) were included between 1 January 2015 and 31 December 2018. Results: A total of 63 598 patients were identified as having PsA [55.9 years (s.d. 14.4), 45.6% males]. The prevalence of PsA was estimated at 0.1% and the incidence at 8.4 per 100 000 person-years in the general population. The most common comorbidities were hypertension, diabetes, chronic obstructive pulmonary disease and dyslipidaemia. The prevalence of treatment with conventional synthetic DMARDs (csDMARDs), biological or biosimilar DMARDs (b/bsDMARDs) and apremilast for PsA was 25.9% (16 453), 30.4% (19 325) and 3.5% (2231), respectively. Overall, 8966 (14.1%) patients were new users of csDMARDs, 8311 (13.1%) were new users of b/bsDMARDs and 1529 (7.4%) were new users of apremilast. The most common first-line csDMARD was methotrexate (70.9%) and the most frequent first-line b/bsDMARD was adalimumab (30.8%). Conclusion: Our results lead to a better understanding of PsA. Results were similar to those from other published studies using other data sources, which highlights the reliability of insurance databases for studies.