Health-related quality of life measures for patients with rheumatoid arthritis and psoriatic arthritis were generally similar, with a tendency toward worse scores among those with psoriatic arthritis, according to findings published in the Annals of the Rheumatic Diseases.
Quality of life measure among patients with RA or PsA were worse than those reported by the general Norwegian population, the researchers added.
“In smaller observational studies performed 1 to 2 decades ago, similar [health-related quality of life] in patients with RA and patients with PsA were described, and also differences in Short Form-36 (SF-36) scale scores,” Brigitte Michelsen, MD, of Diakonhjemmet Hospital, and colleagues wrote. “To our knowledge no large, prospective observational study has compared [health-related quality of life] between patients with RA and patients with PsA and the general population using the widely recognized SF-36.”
Health-related quality of life measures for patients with RA and PsA were generally similar, with a tendency toward worse scores among those with PsA, according to findings.
To compare SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS), scale scores and the Short Form-6 dimensions utility score (SF-6D), between patients with RA, PsA and the general population, and to analyze improvements from baseline to 6 months, Michelsen and colleagues conducted a large, prospective observational study.
The researchers enrolled 3,898 patients with RA and 1,515 with PsA from the Norwegian-Disease Modifying Anti-Rheumatic Drug (NOR-DMARD) study, all of whom began therapy with synthetic or biologic DMARDs between Dec. 1, 2000 and Nov. 6, 2012. All were followed until May 1, 2013, or until they stopped treatment. The researchers also accessed SF-36 data collected in 1996 from 2,323 individuals in the Norwegian general population. Michelsen and colleagues then conducted analyses of covariance to compare SF-36 measures between patients with RA and PsA, adjusting for age and gender.
According to the researchers, patients with PsA and RA had similar PCS, MCS and SF-6D measures (P .14). However, patients with PsA demonstrated worse vitality and general health, but better physical functioning at baseline and 6 months, compared with those with RA (P .03). In addition, PCS, most scale scores and SF-6D were worse among patients with PsA, compared to those with RA, at baseline, 3 months and 6 months, when taking into account additional DAS28 adjustment as a proxy for joint inflammation (P .01).
Mean 3-month and 6-month improvements following treatment with DMARDs were larger in patients with RA than patients with PsA for bodily pain, vitality and mental health (P .02). In addition, in both RA and PsA, PCS was more impaired than MCS compared with individuals in the general population (P .001).
“The study underlines the severe impact of both RA and PsA on [health-related quality of life] reflected through SF-36, which is in line with a smaller observational study as well as clinical trials,” Michelsen and colleagues wrote. “Furthermore, the study highlights the relatively stronger impairment of [health-related quality of life] in patients with PsA compared with patients with RA, when also taking into consideration levels of joint inflammation, as measured by DAS28.” – by Jason Laday
Disclosure: Michelsen reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.