Background: An outcome measure to evaluate the neurological function of cervical myelopathy was proposed by the Japanese Orthopaedic Association in 1975 (JOA score), and has been widely used in Japan. However, the JOA score does not include patients' satisfaction, disability, handicaps, or general health, which can be affected by cervical myelopathy. The purpose of this study was to develop a new outcome measure for patients with cervical myelopathy.
Methods: This study was conducted in eight university hospitals and their affiliated hospitals from February to May 2002. The questionnaire included 77 items. Forty-one questions, which were originally listed by the authors, were for evaluation of the physical function of the cervical spine and spinal cord. The Medical Outcome Study Short-Form 36-Item Health Survey (SF-36) was used to examine health-related quality of life (QOL). Patients with cervical myelopathy and healthy volunteers were recruited at each institution. After analysis of the answers from patients and volunteers, irrelevant questions using the following criteria were excluded: (1) a question 80% of answers for which were concentrated on one choice, (2) a question whose answer was highly correlated with that of other questions, (3) a question that could be explained by other questions, and (4) a question for which the distribution of the answers obtained from the patients was not different from that obtained from the normal volunteers.
Results: The patients comprised 164 men and 86 women, and the healthy volunteers 96 men and 120 women. Thirteen items from the questions about the physical functions of the cervical spine and the spinal cord and 11 items from SF-36 remained as candidates that should be included in the final outcome measure questionnaire.
Conclusion: Twenty-four questions remained as candidates for the final questionnaire. This new self-administered questionnaire might be used to evaluate the outcomes in patients with cervical myelopathy more efficiently.