Back Performance Scale: Assessment of patients with back problems in primary health care

Research question: Is Back Performance Scale (BPS) appropriate for measuring function in patients with low back pain (LBP) treated by physiotherapist in primary health care? Design: Cross sectional study. Material and methods: Two physiotherapists collected data from 52 LBP-patients in different primary care clinics in Norway. The patients performed the BPS-tests and reported their function on Hannover Functional Ability Questionnaire (Hannover) 2 times with 2-3 days a part (test-retest). Results: Based on the BPS test-results and the Hannover scores, LBP patients treated by physiotherapists in primary care seem to have moderate level of functional problems. Many of the patients had no or little problems in performing the individual BPS tests, but the sum score provided a broader picture of their functional ability. BPS had a considerable ceiling effect in this patient group. The BPS tests were significantly correlated with patients’ perception of their own function, thus BPS seems to capture functions that are relevant for patients. The test-retest stability was excellent and the measurement error was acceptable. Conclusion: BPS is a valid instrument for measuring functional ability related to daily activities in LBP patients in primary care. The test-retest stability of is good and the measurement error acceptable, but due to a ceiling effect, BPS is not appropriate for measuring effect of interventions in all patients.