Background: Knowledge about health related quality of life (HRQoL) in Ankylosing spondylitis (AS) is limited. The aims of this study were to assess HRQoL by short form-36 (SF-36) in a cohort of patients with AS compared with controls and to examine associations between SF-36 and spinal radiographic changes, physical function, disease activity and demographic data overall and stratified by sex.
Method: A cohort of patients with AS were assessed with spinal radiographs for mSASSS, BASMI, BASFI, ASDAS-CRP, BASDAI, BASG and SF-36. Each patient’s SF-36 results were compared with 5 age- and sex-matched persons (n=1055) from the SF-36 Swedish normative population database. Associations between SF-36 physical component summary (PCS) and mental component summary (MCS) scores and disease related and demographic factors were investigated with univariate and multiple logistic regression analyses with PCS and MCS below/above their respective median values as dependent variables.
Results: 210 patients, age (median, IQR) 49.0 (40.0, 61.2) years were included. AS patients scored lower (p<0.001) compared to controls in all SF-36 domains and component summaries. Both sexes scored significantly lower in PCS compared to MCS. Multiple logistic regression analyses revealed that living without a partner (OR 2.38, 95% CI 1.00–5.67), long symptom duration (year in decade OR 1.66, 95% CI 1.16–2.37), higher BASFI (OR 1.98, 95% CI 1.46–2.70) and ASDAS≥2.1 (OR 3.32, 95% CI 1.45-7.62) were associated with worse PCS, while living without a partner (OR 3.04, 95% CI 1.34–6.91), fatigue (VAS global fatigue >median (OR 6.36, 95% CI 3.06–13.19) and ASDAS≥2.1 (OR 2.97, 95% CI 1.41–6.25) were associated with worse MCS.
Conclusions: AS patients had significantly lower HRQoL compared with controls. PCS was more affected than MCS in both sexes. Both disease related and demographic factors were associated with HRQoL, partly overlapping for PCS and MCS. Factors associated with HRQoL showed some differences between sexes. Modifying factors, such as ASDAS-CRP and fatigue, may improve HRQoL.