Assessing back pain: does the Oswestry Disability Questionnaire accurately measure function in ankylosing spondylitis?

OBJECTIVE: To determine whether the Oswestry Disability Questionnaire (ODQ) can be used to assess the degree of pain or disability in patients with ankylosing spondylitis (AS).

METHODS: The ODQ was administered to a cohort of patients with AS. The resulting pain scores were correlated to the conventional measures in AS, the Bath AS Disease Activity Index and Functional Index (BASDAI and BASFI), as well as the Total and Nocturnal Back Pain scores, and the patient global assessment score.

RESULTS: A total of 49 patients with AS were assessed (38 men, 11 women), mean age 40 years (range 17-68). The mean ODQ score was 40/100 (range 0-92), the mean BASDAI 3.7/10 (range 0-9.5), the mean BASFI 3.3/10 (range 0-9.7), the mean total back pain score 3.7/10 (range 0-10), and the mean patient global assessment score 3.6/10 (range 0-10). Correlation between the ODQ and the traditional AS outcome measures was very good, with a correlation coefficient of r = 0.73 (BASFI) and r = 0.70 (BASDAI). Correlations between the ODQ and the total back pain score (r = 0.70) and the patient self-reported global assessment (r = 0.61) were good.

CONCLUSION: The strong correlations between the ODQ and BASFI and BASDAI indicate that it identifies both activity and function domains in AS. This is the first demonstration of a role for this outcome measure in the assessment of patients with AS.