Purpose: There currently is a paucity of well-validated instruments to quantitatively measure physical activity (PA) levels in patients with fibromyalgia syndrome (FMS). This study aims to determine the construct validity and test-retest reliability of two self-report physical activity questionnaires [short-form international physical activity questionnaire (s-IPAQ) and community health activities model program for seniors (CHAMPS)] in a fibromyalgia population.
Methods: Thirty subjects (mean age 49.1 +/- 9.6 years; 90% females) who met the American College of Rheumatology criteria for FMS were invited to participate in the study. Two-week test-retest reliability was evaluated for the CHAMPS and s-IPAQ. Construct validity was evaluated by comparing PA reported from these questionnaires with data obtained from accelerometry (steps/week, counts/week) and the 6-minute walk test (6-MWT).
Results: CHAMPS showed greater test-retest reliability (r = 0.58; p < 0.001) compared with s-IPAQ (r = 0.18; p = 0.15). No significant correlations were observed between the self-report PA questionnaires and the 6-MWT or accelerometry data (p > 0.05).
Conclusions: In a fibromyalgia population, the s-IPAQ does not appear to be a reliable and valid PA assessment tool. CHAMPS displayed moderate test-retest reliability; however, no associations were found between CHAMPS and objectives measures of PA. In view of the known benefits of exercise in patients with FMS, there is a need to develop new measures or validate other existing well-established PA questionnaires.