Comparison of Six Common Outcome Measures for Surgical Fixation of Distal Radius Fractures - Responsiveness, Ceiling-bottom Effects and Minimal Detectable Changes

Abstract

Introduction: Standardised reporting of outcomes in healthcare is important in clinical documentation, quality assurance and research. We aimed to compare the performance of six commonly used outcomes instruments. Methods: This is a prospective cohort study which included patients with acute distal radius fractures treated with plate fixation. We assessed six outcomes instruments: the Cooney modification of the Green and O’Brien score (MGNO), the Sarmiento modification of Gartland and Werley score (GNW), the shortened questionnaire for Disabilities of the Arm Shoulder and Hand (QDASH), the patient-rated wrist evaluation questionnaire (PRWE), wrist flexion an extension range of motion arc (FEarc), and hand grip strength fraction (GripFrac). Statistical analysis included standardisation of scales (converted to a linear 0-100 point scale), responsiveness (Cohen’s d effect size), ceiling and floor effects, minimal detectable change, and criterion validity. Results: A total of 259 patients were recruited, and the mean age was 55.6 years old. In 6 weeks to 3 months, GripFrac and FEarc were the most responsive. In 3 months to 6 months, GripFrac was the most responsive. From 6 months to 12 months, GripFrac, PRWE, QDASH, and MGNO were most responsive. From 12 months to 24 months, PRWE and MGNO were the most responsive. Significant correlations were obtained for all outcome measures. Except for FEarc, all other scores had ceiling effects. Conclusion: Different outcome measures differ considerably in responsiveness, and even the same outcome measures had different responsiveness when used to assess different timeframes during rehabilitation.