Treatment patterns, unmet need, and impact on patient-reported outcomes of psoriatic arthritis in the United States and Europe

Psoriatic arthritis (PsA) is a chronic, inflammatory disease. The effects of PsA real-world treatment patterns on patient-reported outcomes in the US and 5 European countries (EU5; France, Germany, Italy, Spain, UK) were evaluated. Respondents from the 2016 National Health and Wellness Survey received advanced therapies (e.g., biologic disease-modifying antirheumatic drugs [DMARDs]), other therapies, (e.g., conventional synthetic DMARDs), or no treatment. Assessments included demographics, disease severity (patient-reported), comorbidities (Charlson Comorbidity Index), health status (Short Form-36 Health Survey), depression (Patient Health Questionnaire-9), work productivity (Work Productivity and Activity Index), and treatment adherence (Morisky Medication Adherence Scale-8). Overall, 1037 respondents from the US and 947 respondents from the EU5 were included. Of these, 21.7% US and 7.3% EU5 respondents received advanced therapies; 16.6% and 28.5%, other therapies; and 61.7% and 64.2%, no treatment, respectively. During treatment with advanced or other therapies, 40.8-54.7% US and 57.7-58.9% EU5 respondents self-reported moderate or severe PsA. Respondents receiving advanced therapies had the highest Charlson Comorbidity Index score (US, 1.25; EU5, 1.42); the lowest scores were with no treatment (0.52 and 0.49, respectively). Employment was lowest with other therapies (US, 47.7%; EU5, 41.1%). Overall work impairment was reported by 57.9% US and 62.6% EU5 respondents receiving advanced therapies. Medication adherence was generally low in the US and medium in the EU5 (Morisky Medication Adherence Scale-8: low, US 40.1-46.7%, EU5, 29.0-35.2%; medium, US 29.3-36.1%, EU5 37.8-49.3%; high, US 23.8-24.0%; EU5, 21.7-27.0%). Advanced and other therapies reduced PsA severity; however, >40% of respondents reported moderate or severe PsA during treatment. Better management and adherence may reduce unmet need and disease burden. Further work is required to improve PsA diagnosis and time to treatment initiation.