Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire: Part 3. Determination of reliability

BACKGROUND The manner of measuring the outcome of cervical myelopathy must be patient-oriented and have sufficient reliability and validity. The current Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy is widely used but has not met this requirement. The first- and second-round surveys established 24 items for inclusion on a new questionnaire for cervical myelopathy. The purpose of this study (the third-round survey A) was to confirm the reproducibility of patient responses to the selected questions. METHODS A total of 201 patients with cervical myelopathy and with no change of symptoms between the two interviews were included. Each patient was interviewed twice using the same questionnaire at an interval of 4 weeks. The reliability of the questionnaire was evaluated by determining the extension of the weighted kappa coefficients. RESULTS The weighted kappa coefficient for each item was >0.4, confirming that the test-retest reliability was acceptable. CONCLUSIONS The newly developed JOA Cervical Myelopathy Evaluation Questionnaire was proven to have sufficient reliability.