Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) in mainland China: an investigation of reliability, validity, and responsiveness

BACKGROUND: The aim of this study is to investigate the reliability, validity, and responsiveness of JOACMEQ for CSM patients in mainland China. METHODS: A retrospective review was performed on 91 patients with CSM in our hospital from March 2015 to June 2015. Patients completed the JOACMEQ, the mJOA and the SF-36 questionnaires during the process. Cronbach's α was used to evaluate the internal consistency reliability, and test–retest reliability was checked. An exploratory factor analysis was used to determine the correlations among the JOACMEQ questions and the construct validity. The concurrent validity was assessed by Spearman correlation coefficient. The internal responsiveness was determined by effect sizes and standardized response means. External responsiveness was determined by the area under the receiver operating characteristic curve on the basis of the Youden Index. RESULTS: The mean age of patients was 57.61 years old. The mean follow-up was 24 months. JOACMEQ showed a good internal consistency (Cronbach's α, 0.897). Test–retest reliability showing good result (Pearson's correlation, 0.695–0.905). Our data were amenable to factor analysis (KMO = 0.816, Bartlett's test, χ(2)(45) = 1199.99, p < 0.001), and five factors above 1 were strongly loaded and clustered for each of the five factors. Comparing the scales preoperative to those 2 years postoperative, the average scores of the subscales all increased, and both the ES and SRM showing satisfied responsiveness. In external responsiveness analysis, the recovery rate a appeared to be most responsive to post-operative improvement. CONCLUSIONS: The Simplified Chinese version of JOACMEQ was well-developed with great reliability and sensitive responsiveness. Our study demonstrated that JOACMEQ has content psychometric properties to identify postoperative improvements in CSM patients.