JOA back pain evaluation questionnaire: Initial report

Background. There is no widely accepted objective evaluation for lumbar spine disorders. New outcome measures should be patient-oriented and should measure symptoms and self-reported functional status in multiple dimensions. The aim of this study was to identify items to be included in the disease-specific quality of life (QOL) questionnaire for the assessments of patients with lumbar spine disorders. Methods. The draft of the QOL questionnaire that consisted of a total of 60 items, including 24 items derived from the Japanese version of the Roland Morris Disability Questionnaire (RDQ) and 36 items derived from the Japanese version of Short Form 36 (SF-36), were administered to patients and controls. After obtaining written informed consent, the following data were collected from the patient group (n = 328) and the control group (n = 213): (1) background characteristics, including age, diagnosis, Japanese Orthopaedic Association (JOA) score, and finger to floor distance; (2) responses to the questionnaire; (3) the identification rate by discrimination analysis to select the candidates for adoption and by adopting explanatory variables. The items to be excluded were determined by examining the explanatory variables, which were selected after the discrimination analysis, by setting the candidate to-be-excluded items as an objective variable. Results. Based on the distribution of the responses, two items, RDQ-15 and RDQ-19, were excluded. From the results of the correlation coefficient calculation for each question in the patient group, 33 items were excluded and 27 candidate items were adopted. Based on the adoption explanatory variable used in the discrimination analysis, 25 of the 27 candidate items for adoption were accepted. Conclusions. This study identified the 25 specific questionnaire items that should be included in the questionnaire to evaluate QOL of patients with various lumbar spine disorders.