Health-related quality of life is similar among patients with rheumatoid arthritis (RA) and those with psoriatic arthritis (PsA), with a tendency toward worse scores in patients with PsA, and worse scores compared with those of a group of Norwegian population controls, according to data published in the Annals of the Rheumatic Diseases.
The investigators used data derived from first-time enrollees with RA and PsA in the prospective, multicenter, longitudinal, observational Norwegian-Disease Modifying Anti-Rheumatic Drug (NOR-DMARD) study. They sought to compare Short Form-36 (SF-36) Physical Component Summary (PCS) scale scores, SF-36 Mental Component Summary (MCS) scale scores, and Short Form-6 dimensions (SF-6D) between patients with RA and patients with PsA and controls. Researchers also sought to compare improvements in these measures between patients with PsA and those with RA.
A total of 3898 participants with RA, 1515 participants with PsA, and 2323 general population controls were included in the study. Mean patient age was 55.9±31.6 years, 48.1±12.6.years, and 44.9±16.5 years, respectively.
Based on age- and gender-adjusted analyses, participants with PsA had similar PCS, MCS, and SF-6D scores compared with those with RA (P ≥.014). In addition, patients with PsA had worse vitality and general health, but significantly better physical functioning at baseline and at 6 months (P ≤.03).
When 28-joint disease activity scores were considered in addition to gender and age, patients with PsA had significantly worse PCS and SF-6D scores at baseline, at 3 months, and at 6 months compared with those with RA (P ≤ .01).
PCS was reported to be more significantly impaired than MCS among both the RA and PsA groups compared with the general population controls (P ≤.001). Following treatment with disease-modifying antirheumatic drugs, mean 3-month and 6-month improvements were greater among patients with RA compared with those with PsA for bodily pain, vitality, and mental health (P ≤.02).
The investigators noted that the major strength of this study was its prospective, multicenter, observational design, which included large cohorts of patients with RA and PsA over a long period of time, along with a large number of Norwegian population controls. This study appears to be the largest observational prospective study to date to compare SF-36 scores between patients with PsA and those with RA, as well as the first to compare SF-36 component summaries, scale scores and SF-6D scores among patients with RA and PsA and general population controls in the same analysis.
Michelsen B, Uhlig T, Sexton J, et al. Health-related quality of life in patients with psoriatic and rheumatoid arthritis: data from the prospective multicentre NOR-DMARD study compared with Norwegian general population controls [published online June 6, 2018]. Ann Rheum Dis. doi: 10.1136/annrheumdis-2018-213286