J E Bolton1, A C Breen. 1. Anglo-European College of Chiropractic, Bournemouth, England. jbolton@aecc-chiropractic.ac.uk
Abstract
OBJECTIVE: Develop and test a short-form comprehensive outcome measure for back pain. DESIGN: Prospective longitudinal study of 3 consecutive cohorts of back pain patients. SETTING: Anglo-European College of Chiropractic outpatient clinic and several field chiropractic practices. METHOD: Domains judged important in the back pain model and responsive to clinical change were identified from the literature. Items were scored on an 11-point numerical rating scale. The instrument was psychometrically tested by use of those tests relevant to an evaluative measure. RESULTS: Seven dimensions of the back pain model were included in the questionnaire. Having established face validity, the instrument was shown to demonstrate high internal consistency (Cronbach's alpha = 0.9) and good test-retest reliability (ICC = 0.95). All items were retained on the basis that they contributed to the overall score (item-corrected total score correlations) and to the instrument's responsiveness to clinical change (item change-corrected total change score correlations). The instrument demonstrated acceptable construct and longitudinal construct validity with established external measures. The effect size of the instrument was high (1.29) and comparable with established measures. CONCLUSION: A reliable, valid, and responsive instrument has been developed for use in back pain patients. It is practical for use in investigations of both the efficacy and effectiveness of back pain treatments.
OBJECTIVE: Develop and test a short-form comprehensive outcome measure for back pain. DESIGN: Prospective longitudinal study of 3 consecutive cohorts of back painpatients. SETTING: Anglo-European College of Chiropractic outpatient clinic and several field chiropractic practices. METHOD: Domains judged important in the back pain model and responsive to clinical change were identified from the literature. Items were scored on an 11-point numerical rating scale. The instrument was psychometrically tested by use of those tests relevant to an evaluative measure. RESULTS: Seven dimensions of the back pain model were included in the questionnaire. Having established face validity, the instrument was shown to demonstrate high internal consistency (Cronbach's alpha = 0.9) and good test-retest reliability (ICC = 0.95). All items were retained on the basis that they contributed to the overall score (item-corrected total score correlations) and to the instrument's responsiveness to clinical change (item change-corrected total change score correlations). The instrument demonstrated acceptable construct and longitudinal construct validity with established external measures. The effect size of the instrument was high (1.29) and comparable with established measures. CONCLUSION: A reliable, valid, and responsive instrument has been developed for use in back painpatients. It is practical for use in investigations of both the efficacy and effectiveness of back pain treatments.