Functional assessment in ankylosing spondylitis: evaluation of a new self-administered questionnaire and correlation with anthropometric variables.

We describe the development of a new self-administered questionnaire for assessment of specific disability in ankylosing spondylitis (AS). The questionnaire was derived both from discussion with patients and from previous published material and covered four main areas of function: mobility, bending down, reaching up and neck movements, and posture. Four categories of response were available similar to the Stanford Health Assessment Questionnaire and the questionnaire was similarly scored providing a range of scores from 0-3. The questionnaire was found to be acceptable, understandable, easy to complete and fulfilled recognized criteria for reproducibility and validity. A significant improvement in functional score as a result of treatment was found in a longitudinal study of physiotherapy in 42 subjects with AS (pre-treatment score 1.23 +/- 0.79, post-treatment 1.07 +/- 0.75 P < 0.01). The areas which showed the most improvement were mobility, bending and posture. Functional scores correlated well with some anthropometric variables, particularly cervical movements, finger to floor distance and chest expansion. Both spinal and peripheral joint impairment contributed to functional disability.