The Brighton musculoskeletal Patient-Reported Outcome Measure (BmPROM): An assessment of validity, reliability, and responsiveness

Abstract

Background: In response for the need of a freely available, stand-alone, validated outcome measure for use within musculoskeletal (MSK) physiotherapy practice, sensitive enough to measure clinical effectiveness, we developed an MSK patient reported outcome measure. Objectives: This study examined the validity and reliability of the newly developed Brighton musculoskeletal Patient-Reported Outcome Measure (BmPROM) within physiotherapy outpatient settings. Methods: Two hundred twenty-four patients attending physiotherapy outpatient departments in South East England with an MSK condition participated in this study. The BmPROM was assessed for user friendliness (rated feedback, N = 224), reliability (internal consistency and test–retest reliability, n = 42), validity (internal and external construct validity, N = 224), and responsiveness (internal, n = 25). Results: Exploratory factor analysis indicated that a two-factor model provides a good fit to the data. Factors were representative of “Functionality” and “Wellbeing”. Correlations observed between the BmPROM and SF-36 domains provided evidence of convergent validity. Reliability results indicated that both subscales were internally consistent with alphas above the acceptable limits for both “Functionality” (α =.85, 95% CI [.81,.88]) and ‘Wellbeing’ (α =.80, 95% CI [.75,.84]). Test–retest analyses (n = 42) demonstrated a high degree of reliability between “Functionality” (ICC =.84; 95% CI [.72,.91]) and “Wellbeing” scores (ICC =.84; 95% CI [.72,.91]). Further examination of test–retest reliability through the Bland–Altman analysis demonstrated that the difference between “Functionality” and “Wellbeing” test scores did not vary as a function of absolute test score. Large treatment effect sizes were found for both subscales (Functionality d = 1.10; Wellbeing 1.03). Conclusion: The BmPROM is a reliable and valid outcome measure for use in evaluating physiotherapy treatment of MSK conditions.