Background Psoriatic arthritis (PsA) is a progressive inflammatory joint disease, eventually leading to disability. Patients with PsA have reduced quality of life and functional capacity compared with psoriasis patients or healthy controls, and is comparable to patients with rheumatoid arthritis. We sought to investigate the correlation of functional outcome with detailed clinical, radiological, and laboratory assessments in a large cohort of established PsA patients
Objectives To identify predictors of poorer physical function in patients with established psoriatic arthritis
Methods A consecutive cohort of 283 PsA patients attending rheumatology clinics at St Vincent’s University Hospital, Dublin was included. Following informed consent, patients underwent a detailed skin and rheumatologic assessment including disease activity measures [PASI, Body Surface Area (BSA) for Psoriasis (Ps); DAS 28 CRP], inflammatory markers (CRP and ESR), patient-reported outcome measures (including Health Assessment Questionnaire (HAQ), Dermatology Life Quality Index (DLQI), Bristol Rheumatoid Arthritis Fatigue Numeric Rating Scale (BRAF-NRS), EuroQuol questionnaire (EQ5D), and radiographs were taken for involved joints along with hands, feet and sacroiliac joints. In addition, an extensive medical record review was performed to obtain information regarding their previous psoriatic disease features. The factors predicting poor physical function as measured by the HAQ score were determined using univariate and multivariate logistic regression analysis. Patients were classified as mildly disabled (0–1), moderately disabled (>1–2) or severely disabled (>2–3).
Results A total of 283 PsA patients [mean age 54.6±12 years; 52% female; mean PsA duration=19±9 years; 25% with sacroiliitis; 43.5% with radiographic peripheral joint erosions; median current PASI=2.1] were studied. The mean ± SD HAQ score of the cohort was 0.57± 0.57 (median 0.50). A total of 208 (73.5%) had mild disability, 67 (23.7%) had moderate disability and 8 (2.8%) had severe disability. On univariate analysis, significant association of HAQ score was noted with female gender (p=<0.001), older age (p=<0.001), longer disease duration (p=0.003), smoking (p=0.02), age of Ps onset (p=0.01), disease duration prior to diagnosis (p=0.001), radiographic osteolysis (p=0.012), number of deformed joints on examination (p=0.001), maximum tender joint counts (p=<0.001), maximum swollen joint counts (p=0.001), inversely with Ps preceding PsA (p=0.01), PsA preceding Ps (p=<0.001), DLQI (p=<0.001), BRAF (p=<0.001), EQ5D (p=<0.001). No significant association was noted with BMI, metabolic syndrome, type 1 or type 2 Ps, nail disease, severity of skin Ps, enthesitis, dactylitis, erosions, sacroiliitis, inflammatory markers, PsA or Ps requiring TNFi. On multiple linear regression analysis, the model predicted significant increases in HAQ related to smoking (p=0.009), disease duration prior to diagnosis (p=0.013), female gender (p=<0.001), number of deformed joints on examination (p=<0.001), BRAF (p=0.001), EQ5D (p=<0.001), and later PsA age of onset (p=0.007)
Conclusions Smoking, delay to diagnosis, older age at the diagnosis, female gender, clinically deformed joints, and worse fatigue and quality of health-related life scores are associated with poor functional outcome in a cohort of established patients with PsA.
Disclosure of Interest None Declared