Objective: To evaluate the impact of anti-tumor necrosis factor (anti-TNF) therapies on quality of life (QOL) and functional status in psoriatic arthritis (PsA) patients and study potential predictors for QOL improvements.
Methods: The study was based on a cohort of 596 PsA patients receiving anti-TNF therapies. Changes in functional status and QOL were assessed using the Health Assessment Questionnaire (HAQ) and Short Form 36 (SF-36) questionnaire on a 6-month basis. The Short Form 6D (SF-6D) was calculated as a utility score. Univariate and multivariate linear regression models were developed to examine potential predictors of QOL improvements at 6 months, using a range of demographic, baseline disease-specific, and therapeutic variables.
Results: At 6 months, significant improvements in all SF-36 subscale scores were found, with the greatest percentage improvement from baseline related to physical role (113.8%; 95% confidence interval [95% CI] 102.6, 125.0). The percent improvement for the physical component scale was 53.2% (95% CI 44.5, 61.9) at 6 months, whereas that for the mental component scale was 16.9% (95% CI 14.7, 19.2). The mean +/- SD SF-6D score was 0.58 +/- 0.07 at baseline, and this improved to 0.63 +/- 0.06 at 6 months. The median HAQ score at baseline was 1.88 (interquartile range [IQR] 1.38-2.25) for the entire cohort, and this improved to 1.25 (IQR 0.63-1.88) at 6 months. Improvements in Disease Activity Score in 28 joints at 6 months were found to be significantly associated with QOL improvements at the same time point.
Conclusion: Anti-TNF therapy is associated with improvement in both physical and mental status in PsA patients. These improvements were most substantial in patients who also had improvements in their disease activity.