Assessment of functional ability in younger and older patients with ankylosing spondylitis: performance of the bath ankylosing spondylitis functional index.

OBJECTIVE: To determine whether the Bath Ankylosing Spondylitis Functional Index (BASFI) is applicable in older patients with ankylosing spondylitis and whether it shows major differences between younger and older patients with ankylosing spondylitis.
DESIGN: BASFI total scores and every BASFI item of 202 patients with ankylosing spondylitis aged >or=60 yr (group A) and 267 patients with ankylosing spondylitis aged <or=40 yr (group B) were calculated. The results were compared with the results of the Health Assessment Questionnaire for the Spondyloarthropathies.
RESULTS: The BASFI scores had a median of 4.2 in group A and 2.6 in group B. Marked differences between the age groups were found for every item of the BASFI. Internal consistency was high in both groups. The Spearman correlation coefficient between BASFI and the Health Assessment Questionnaire for the Spondyloarthropathies was rs(A) = 0.83 in group A and rs(B) = 0.78 in group B.
CONCLUSION: The data suggest that the BASFI is also applicable to older patients experiencing AS. There is a significant difference in the BASFI score between younger and older patients with ankylosing spondylitis.