Screening for physical activity in family practice: evaluation of two brief assessment tools.

BACKGROUND Physical activity (PA) is relevant to the prevention and management of many health conditions in family practice. There is a need for an efficient, reliable, and valid assessment tool to identify patients in need of PA interventions. METHODS Twenty-eight family physicians in three Australian cities assessed the PA of their adult patients during 2004 using either a two- (2Q) or three-question (3Q) assessment. This was administered again approximately 3 days later to evaluate test-retest reliability. Concurrent validity was evaluated by measuring agreement with the Active Australia Questionnaire, and criterion validity by comparison with 7-day Computer Science Applications, Inc. (CSA) accelerometer counts. RESULTS A total of 509 patients participated, with 428 (84%) completing a repeat assessment, and 415 (82%) accelerometer monitoring. The brief assessments had moderate test-retest reliability (2Q k=58.0%, 95% confidence interval [CI]=47.2-68.8%; 3Q k=55.6%, 95% CI=43.8-67.4%); fair to moderate concurrent validity (2Q k=46.7%, 95% CI=35.6-57.9%; 3Q k=38.7%, 95% CI=26.4-51.1%); and poor to fair criterion validity (2Q k=18.2%, 95% CI=3.9-32.6%; 3Q k=24.3%, 95% CI=11.6-36.9%) for identifying patients as sufficiently active. A four-level scale of PA derived from the PA assessments was significantly correlated with accelerometer minutes (2Q rho=0.39, 95% CI=0.28-0.49; 3Q rho=0.31, 95% CI=0.18-0.43). Physicians reported that the assessments took 1 to 2 minutes to complete. CONCLUSIONS Both PA assessments were feasible to use in family practice, and were suitable for identifying the least active patients. The 2Q assessment was preferred by clinicians and may be most appropriate for dissemination.