Physical component of SF-36 is associated with measures of disease activity in patients with psoriatic arthritis: a real-life study from a tertiary referral centre.

Psoriatic arthritis (PsA) can lead to chronic disability. The aim of this study was to explore the association between disease activity and quality of life (QoL) in patients with PsA from the usual clinical practice. The study involved 143 consecutive adult patients with PsA (49.6% women and 50.4% males), with mean age of 57.75 ± 10.91 years, and duration of disease 11.6 ± 9 years. Tender (TJC) and swollen joints count (SJC), Disease activity score (DAS) 28, patient's global assessment (PtGA), physician's global assessment (PhGA), enthesitis score, number of fingers with dactylitis, sedimentation rate (ESR) and C-reactive protein (CRP) were evaluated. The functional assessment of chronic illness therapy - fatigue scale (FACIT-F) questionnaire was used in fatigue assessment and physical health domains of Short Form (SF)-36 questionnaire were chosen to assess subjective QoL: physical functioning (PF), role limitations due to physical health (RP), bodily pain (BP) and general health (GH). Significant correlations (p < 0.001) were found between FACIT-F and all SF-36 domains. DAS28, PtGA and PhGA were significantly correlated to two or three SF-36 domains, while ESR and CRP were not significantly correlated to any of SF-36 domains. Regression analysis showed, when controlling for age, that FACIT-F, dactylitis and DAS28 were the most significant predictors of SF-36 physical health domains. Regression and factor analyses confirmed that FACIT-F was most consistently associated with SF-36 physical health domains. In our real-life study most of the analyzed clinical measures of PsA were significantly associated with physical health domains of SF-36 questionnaire. Considering the strength of those associations, we conclude that PsA activity has mild to moderate impact on health-related Qol.