Health-related quality of life was significantly compromised in patients with ankylosing spondylitis (AS), a Swedish study found.
On the physical component summary of the Medical Outcome Survey Short Form (SF)-36, patients with AS had scores of 41.3 compared with scores of 49.1 among healthy controls on the 100-point scale where 50 is average (P<0.001), according to Helena Forsblad-d'Elia, MD, PhD, of Umeå University in Umeå, Sweden, and colleagues.
And on the mental component summary of the SF-36, AS patients had a mean score of 44.6 compared with 50.5 among controls (P<0.001), the researchers reported online in Arthritis Research & Therapy.
The most important factors for worse mental component summary scores in men were greater education, higher fatigue, and fewer radiographic spinal changes, which the researchers speculated may “be explained by adaptive coping strategies in patients with a longstanding chronic disease.” For women, the greatest contributions were from high fatigue, ASDAS of 2.1 or higher, and living alone without a partner.
A major implication of this analysis is that certain factors such as fatigue and disease activity may be modifiable, which in turn could improve quality of life for these patients, the researchers pointed out. In addition, focusing on social life and community support could be of benefit for those who live alone.
“Health-related quality of life is a multi-dimensional concept including not only a person’s physical well-being, but also a person’s mental health and physical ability, both as an individual and as a participating member of the community,” they wrote.
To see the effects of the pain and decreased physical function and mobility on health-related quality of life in AS patients, Forsblad-d’Elia’s group recruited 210 patients from three centers in Western Sweden and compared them with five age- and sex-matched controls from the Swedish normative population database.
A total of 57.6% were men, median age was 49, and median symptom duration was 24 years.
Spinal changes as measured and graded on the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) averaged 13.9. Treatment for 34.8% of patients included a tumor necrosis factor inhibitor and/or a conventional disease-modifying antirheumatic drug.
Women had higher erythrocyte sedimentation rates and global fatigue, while men had higher mSASSS and body mass index, and also more often were HLA-B27 carriers and had more severe spinal changes. On individual components of the SF-36, women had worse scores for physical function, vitality, and mental health compared with men.
When the researchers looked at health-related quality of life according to age, they found that the SF-36 physical component score was significantly lower in the oldest patients (those 61 and older) compared with the youngest (40 or younger).
Multivariate logistic regression analyses showed worse physical component scores associated with the following:
- Living alone without a partner, OR 2.38 (95% CI 1-5.67)
- Longer symptom duration, OR 1.66 per decade (95% CI 1.16-2.37)
- Higher Bath Ankylosing Spondylitis Functional Index (BASFI) score, OR 1.98 per unit (95% CI 1.46-2.70)
- Ankylosing Spondylitis Disease Activity Score (ASDAS) of 2.1 or greater, OR 3.32 (95% CI 1.45-7.62)
In the sex-stratified analysis, the most important factors for worse physical component summary score in men were high BASFI and ASDAS of 2.1 or greater, whereas high BASFI was most influential in women.
For the mental component summary scores, worse scores were associated with these factors:
- Living alone without a partner, OR 3.04 (95% CI 1.34-6.91)
- Global fatigue greater than the median score, OR 6.36 (95% CI 3.06-13.19)
- ASDAS ≥ 2.1, OR 2.97 (95% CI 1.41-6.25)
In discussing their findings, the authors pointed out that the physical component summary score was more compromised than the mental component summary score for both sexes, and that both demographic and disease-related factors contributed to poor quality of life.
A limitation of the study was its cross-sectional design, and longitudinal data are needed.
“We intend to investigate factors related to the change in health-related quality of life over a 5-year period in this same cohort of patients with AS in a future study,” the researchers concluded.
The study was funded by the Health and Medical Care Executive Board of the Vastra Gotaland, Goteborg’s Association against Rheumatism, Vasterbotten’s Association Against Rheumatism, the Swedish Research Council, the Swedish Association Against Rheumatism, the Swedish Society of Medicine, the Goteborg Medical Society, the Region Vastra Gotaland, and the County of Vasterbotten.
The authors reported financial relationships with Novartis, Celgene, Merck Sharp & Dohme, Sandoz, and AbbVie.