Background: Complications associated with psoriatic arthritis (PsA) may be prevented with early diagnosis and initiation of therapy. Up to one third of psoriasis patients may have PsA. There is a need to screen psoriasis patients early for symptoms of PsA.
Objective: To develop and validate a patient self-administered tool to screen psoriasis patients for signs and symptoms of inflammatory arthritis.
Methods: The questionnaire (PASE; Psoriatic Arthritis Screening and Evaluation) was developed using standardized methodology for the development of both functional and health-related instruments geared toward musculoskeletal diseases. A multidisciplinary team of dermatologists, rheumatologists, and patient focus groups were involved in the design of the questionnaire.
Results: A total of 69 participants with known psoriasis and PsA before the initiation of systemic therapy were screened with PASE after institutional review board approval. The average age was 51 years, and 51% of the participants were female. A total of 25% (17/69) were diagnosed with PsA in this study, and 37% (24/69) were diagnosed with osteoarthritis. Patients with concomitant PsA and osteoarthritis were excluded. PASE total scores ranged from 23 to 68 (possible range, 15-75). In patients with PsA, the median total score was 53 (25th and 75th percentiles, 49 and 63, respectively) and 39 (25th and 75th percentiles, 28 and 47) in non-PsA patients (P < .001). Median PASE total score for osteoarthritis patients was 43 (25th and 75th percentiles, 37 and 51) and significantly different to PsA patient total median scores (P = .002). Using receiver operator curves, we determined that PASE total score > or =47 was able to distinguish PsA from non-PsA patients with 82% sensitivity and 73% specificity.
Limitations: PASE is a screening tool for PsA and does not replace a comprehensive musculoskeletal evaluation by a rheumatologist.
Conclusion: The PASE questionnaire is a self-administered tool that can be used to screen for PsA among patients with psoriasis. PASE can distinguish between symptoms of PsA and osteoarthritis. A larger study is needed to validate PASE in dermatology clinics in the community.