To assess the impact of ankylosing spondylitis (AS) on patient health-related quality of life (HRQOL) relative to both the general US and chronically-ill populations, and to evaluate whether etanercept therapy can reverse impairments in HRQOL due to AS.
Two AS patient populations were evaluated: patients with AS from a US clinical trial who were randomized to receive either etanercept (n = 20) or placebo (n = 20) for 16 weeks, and placebo-treated patients from a multinational sample who subsequently received etanercept (n = 129) during a 48-week, open-label extension study. A sample from the US general population and patients with other medical conditions derived from the National Survey of Functional Health Status were used as comparators to evaluate the relative impact of active AS on HRQOL, as measured by the Short Form 36 (SF-36) questionnaire.
At baseline, patients with AS in both the US and multinational samples had significantly lower scores than the US general population on all 8 SF-36 scales. Compared with patients with other medical conditions, patients with AS had the lowest scores in the physical domains—Physical Functioning, Role Physical, and Bodily Pain. Impairments in SF-36 scores for psychosocial domains, such as Social Functioning, Role Emotional, and Mental Health, were somewhat less pronounced in patients with AS. Treatment with etanercept significantly improved the HRQOL of patients with AS on all 8 SF-36 scales, especially in the same physical domains that showed the greatest impairments prior to treatment (Physical Functioning, Role Physical, and Bodily Pain).
Patients with active AS despite conventional therapy have significantly reduced HRQOL across a wide range of domains. These reductions are most pronounced in the physical domains and exceed those seen in many other chronic diseases. Etanercept therapy significantly improves patient HRQOL, indicating that decrements in HRQOL due to AS may be at least partly reversible.