Back beliefs among elderly seeking health care due to back pain; psychometric properties of the Norwegian version of the back beliefs questionnaire

BACKGROUND: The Back Beliefs Questionnaire (BBQ) is a 14-item patient-reported questionnaire that measures attitudes and beliefs about the consequences of back pain. The BBQ has recently been translated into Norwegian, but its psychometric properties have not yet been tested. The aim of this study is to evaluate the reliability and construct validity of the BBQ when used on elderly patients with back pain. METHOD: A prospective cohort study with a test-retest design among 116 elderly patients (> 55 years of age) seeking primary care for a new episode of back pain. Test-retest, standard error of measurement (SEM), minimal detectable change (MDC), internal consistency and construct validity by a priori hypotheses (Spearman’s- and Pearson correlation coefficient) were tested. RESULTS: A total of 116 patients, mean age (SD) 67.7 (8.3), were included and 63 patients responded to the test-retest assessment. The mean (SD) BBQ sum scores (range 9–45) were 29.8 (7.0) and 29.2 (6.7) for the test and retest respectively. The test-retest was acceptable with an intraclass correlation coefficient of 0.71 (95% CI, 0.54–0.82), SEM was 3.8 and MDC 10.5. Internal consistency with Cronbach’s alpha was good (0.82) and acceptable construct validity was supported by the confirmation of 75% of the a priori hypotheses. CONCLUSION: The Norwegian version of the BBQ demonstrated acceptable test-retest reliability and good construct validity and can be used to assess pessimistic beliefs in elderly patients with back pain.