Construct validation of the Japanese Core Outcome Measures Index and the impact of diseases on patient-reported outcome measures in preoperative patients with lumbar spinal stenosis and disk herniation: a single-center observational study

Abstract Purpose The primary objective was to validate the construct validity of the Japanese Core Outcome Measures Index (COMI) in preoperative patients aged 60 years or older undergoing lumbar spine surgery for lumbar spinal stenosis (LSS) and lumbar disk herniation (LDH). Additionally, as a secondary aim, we explored the impact of these diseases on quality of life (QOL). Methods The analysis included 199 preoperative patients aged 60 and above who were scheduled for lumbar spine surgery. To assess QOL, Japanese versions of the COMI, Oswestry Disability Index (ODI), EuroQol-5 Dimension-3 Level (EQ-5D-3L), and SF-12v2 were employed. The study assessed the validity of the COMI and compared demographic and clinical characteristics between the LSS (147 cases) and LDH (52 cases) groups. It used multivariate covariance analysis (MANCOVA) to examine the impact of diseases (LSS and LDH) on each patient-reported outcome measure while considering covariates. Results Compared to the LSS group, the LDH group showed more difficulty with the COMI summary score (LSS/LDH mean: 6.9/8.1, p < 0.001), ODI score (46.8/57.4, p < 0.001), and EQ-5D utility (0.53/0.43, p < 0.001). The LDH group also reported more difficulties in the COMI-function, COMI-symptom-specific well-being, COMI-disability, ODI-personal care, ODI-social life, and SF-12v2-bodily pain subscales. MANCOVA demonstrated that these results were not influenced by covariates such as gender and medical history. Conclusions This study highlights the distinct impact of LSS and LDH on preoperative QOL in older patients undergoing lumbar spinal surgery. Tailored interventions are essential to address the specific challenges posed by these conditions and improve patient-centered outcomes and postoperative recovery.