ABSTRACT Background and Aims The measurement properties of the Japanese Oswestry Disability Index (ODI) and the effects of site‐specific pain and numbness on disability in preoperative patients with lumbar spinal stenosis (LSS) remain insufficiently explored. This study aimed to evaluate the factor structure and reliability of the ODI and examine the influence of pain and numbness on disability. Methods A total of 147 preoperative patients with LSS aged 60 and above, scheduled for lumbar spine surgery, were included. Demographic and clinical data, including pain and numbness levels using the numerical rating scale (NRS), were collected. We excluded the sexual life item from the ODI, and the analysis was conducted using the remaining nine items. This exclusion was considered in the interpretation of the measurement properties. Exploratory factor analysis (EFA), Cronbach's α , and regression analysis were used to evaluate the factor structure, reliability, and the effect of symptoms on disability. Results The sample (mean age 73.3 years) included 72.1% males. The mean ODI score was 46.8% (“severe disability”). EFA identified two latent factors: Daily living (e.g., personal care, sitting, sleeping) and Social living (e.g., traveling, social activities), with a moderate inter‐factor correlation ( r = 0.62). Cronbach's α indicated high internal consistency (0.8 for daily living and social living). In the multivariable regression analyses, low back pain ( β = 0.33, p < 0.001), leg pain ( β = 0.22, p = 0.006), and foot pain ( β = 0.17, p = 0.02) were significantly associated with the Daily living factor, whereas low back pain ( β = 0.22, p = 0.01) and leg pain ( β = 0.20, p = 0.02) were significantly associated with the Social living factor. Numbness showed weaker associations with both factors. Conclusions The Japanese ODI is a reliable tool for assessing disability in preoperative patients with LSS, with distinct factors for daily and social functioning. Pain management for the low back, leg, and foot may play an important role in optimizing patient care.
Mizoguchi et al. (Wed,) studied this question.