Predictors of Health-Related Quality of Life Identified in Ankylosing Spondylitis
Factors affecting health-related quality of life included disease duration and gender.
Study data published in Arthritis Research & Therapy outline several clinical factors that affect health-related quality of life in patients with ankylosing spondylitis (AS), including disease duration and gender.
A cohort of 210 patients with AS from western Sweden (57.6% men) of mean age 49.0 years and mean symptom duration 24.0 years were assessed for health-related quality of life using the Short Form-36 (SF-36). Patients were also assessed for disease activity using the Modified Stoke Ankylosing Spondylitis Spine Score, as well as by clinical examinations and self-report questionnaires. Patient SF-36 results were compared with those of 5 age- and sex-matched controls (n=1055) from the SF-36 Swedish normative population database. The effect of disease-related and demographic factors on SF-36 results were quantified with logistic regression analyses.
Patients with AS scored significantly lower compared with controls in all SF-36 domains and component summaries (all P <.001). Mean SF-36 physical component scores were 42.4 and 52.4 in patients with AS and controls, respectively. Similarly, the mean SF-36 mental component score was 47.9 in patients with AS, compared with 54.1 in controls. Both men and women with AS scored lower in physical component summary compared with mental component summary; however, the phenotype of AS was found to differ between sexes. Specifically, men with AS reported a greater number of AS-related spinal radiographic changes compared with women, whereas women scored worse in 2 mental domains and 1 physical domain compared with men.
According to multivariable logistic regression analyses, factors associated with worse physical component summary included living without a partner (odds ratio [OR], 2.38; 95% CI, 1.00-5.67), long symptom duration (OR, 1.66; 95% CI, 1.16-2.37), greater Bath Ankylosing Spondylitis Functional Index (OR, 1.98; 95% CI, 1.46-2.70), and Ankylosing Spondylitis Disease Activity Score ≥ 2.1 (OR, 3.32; 95% CI, 1.45-7.62). In comparison, living without a partner (OR, 3.04; 95% CI, 1.34-6.91), fatigue (OR, 6.36; 95% CI, 3.06-13.19), and Ankylosing Spondylitis Disease Activity Score ≥2.1 (OR, 2.97; 95% CI, 1.41-6.25) were associated with worse mental component summary.
Patients with AS displayed significantly lower health-related quality of life compared with the general population, with physical domains more greatly affected than mental domains. Disease-related factors associated with decreased quality of life may be appropriate targets for intervention. Differences in AS phenotype observed between sexes also require further research.
Law L, Rehnman JB, Deminger A, Klingberg E, Jacobsson LTH, Forsblad-d'Elia H. Factors related to health-related quality of life in ankylosing spondylitis, overall and stratified by sex. Arthritis Res Ther. 2018;20(1):284.