Disability motivates patients with ankylosing spondylitis for more frequent physical exercise.

Objective: To evaluate whether patients with ankylosing spondylitis who perform disease-specific exercises more frequently have fewer functional limitations and disability than those who exercise more often.

Design: Cross-sectional; retrospective chart review.

Setting: Rehabilitation center in Austria.

Participants: A sample of 1,500 patients with ankylosing spondylitis (1,163 men, 337 women; mean age +/- standard deviation, 50+/-12 y; disease duration, 21+/-11 y) grouped by how many times per week they performed disease-specific exercises for at least 5 minutes: group A (n=542), less than 1 time; group B (n=691), 1 to 3 times; and group C (n=267), more than 3 times.

Interventions: Not applicable.

Main Outcome Measures: Self-report of exercise frequency and a German version of the Health Assessment Questionnaire for the spondyloarthropathies (HAQ-S).

Results: The HAQ-S showed significant differences among the groups (analysis of variance on ranks, P<.001). In pairwise multiple comparison, group A showed significantly less disability (median, 0.5; interquartile range [IQR], 0.2-0.8) than group B (median, 0.6; IQR, 0.3-0.9) or group C (median, 0.7; IQR, 0.3-1.0).

Conclusion: Patients with less disability exercised less than their more disabled counterparts. The reasons for this difference, particularly the issue of motivation, deserve more attention.