Patients with systemic sclerosis (SSc) have worse health-related quality of life than patients with other systemic rheumatic diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), a Korean study found.
Among patients with SSc, the composite mental component score on the Short Form (SF)-36 health survey was 43, compared with 48.9 among those with RA (P<0.001) and 46.6 among those with SLE (P=0.006), according to Eun Bong Lee, MD, of Seoul National University College of Medicine, and colleagues. Higher numbers on the 100-point SF-36 represent better quality of life.
In addition, on the physical domain of the SF-36, general health was significantly worse for the SSc group than the RA group (41.4 vs 51.3, P<0.001). In contrast, among healthy controls the mental component score on the SF-36 was 50.8 and the general health score was 63.9, the researchers reported online in Arthritis Research & Therapy.
SSc, or scleroderma, is characterized by the presence of autoantibodies, fibrosis of the skin and internal organs, and damage to the vasculature. “Affected patients experience poor survival owing to derangements in the function of various internal organs, including interstitial lung disease, pulmonary arterial hypertension, renal crisis, gastroesophageal reflux, and congestive heart failure,” the researchers explained.
Previous studies have identified worse health-related quality of life among SSc patients compared with the general population, with difficulties comparable to those experienced by patients with diseases such as hypertension and diabetes, but little is known about how these patients fare compared with patients with other rheumatic diseases.
To examine this, Lee and colleagues enrolled 480 patients: 120 each with SSc, RA, SLE, and Sjogren’s syndrome, along with 600 healthy controls. Health-related quality of life was assessed on the SF-36 mental and physical components, the Short Form-6 Dimensional (SF-6D) health index, and the EuroQol Five Dimensional descriptive system.
Disease activity among RA patients was moderate, with a mean Disease Activity Score in 28 joints of 3.56; moderate to high in SLE patients, with a mean SLE Disease Activity Index of 6.26; and low in the Sjogren’s group (1.52) because most patients with Sjogren’s were without central nervous system or renal involvement.
In the SSc group, two-thirds had the more extensive diffuse cutaneous subtype. Mean Health Assessment Questionnaire Disability Index was 0.99, mean Scleroderma-Specific Health Assessment Questionnaire score was 0.87, and mean modified Rodnan skin score was 15.6.
On the mental health subscale of the SF-36, patients with SSc had lower scores (61.3) than patients with RA (71.7, P<0.001) or SLE (67.2, P=0.020). In addition, scores for SSc were worse for SSc than for RA on the SF-6D (0.70 vs 0.73, P=0.056) and the EuroQol scale (63.98 vs 69.95, P=0.005).
Body mass index showed a positive correlation with the SF-36 physical component score (β = 0.32, P=0.022), whereas these factors had negative correlations:
- Disease duration, β = -0.08, P=0.009
- Digestive involvement, β = -3.69, P<0.001
- Pulmonary involvement, β = -2.68, P=0.004
- Disease severity, β = -3.18, P=0.003
Modified Rodnan skin scores also were significantly associated with the SF-36 physical component score (β = -0.25, P=0.001) and the mental component score (β = -0.28, P=0.021), indicating that more extensive skin involvement was associated with decreased health-related quality of life.
The observation that patients with SSc had poorer quality of life than patients with RA or SLE may reflect the different disease patterns and severity, with SSc typically having a more progressive course, disfiguring skin disease, and pronounced psychological stress.
“The results of this study indicate that we should pay more attention to the reported health-related quality of life and psychological status in patients with SSc,” the authors stated.”Furthermore, early diagnosis and assessment of organ involvements, as well as early, tailored, appropriate organ-based treatment would be advantageous to ensure better quality of life in SSc patients.”
A limitation of the study, the team said, was its inclusion of only Korean patients, limiting its generalizability.
The study was funded by the National Research Foundation of Korea and the Ministry of Education.
The authors reported having no competing interests.