Predicting clinically important difference in lumbar decompression surgery: the influence of demographic, clinical, and radiographic characteristics

BACKGROUND: Lumbar decompression is a common intervention for spinal stenosis and disc herniation, yet many patients fail to achieve a minimal clinically important difference (MCID) in disability. Identifying predictors of MCID may optimize patient selection and improve surgical outcomes. PURPOSE: To identify demographic, clinical, and radiographic predictors of MCID achievement one year after lumbar decompression, and to develop a preoperative risk stratification tool. STUDY DESIGN/SETTING: Prospective cohort study using a single-center spine registry. PATIENT SAMPLE: A total of 199 patients undergoing 1- to 4-level lumbar decompression (laminectomy, microdiscectomy, or laminotomy) from 2020 to 2023. OUTCOME MEASURES: Oswestry disability index (ODI) improvement meeting MCID, defined as ≥12.8-point improvement or ≥50% improvement if baseline ODI ≤26, per validated thresholds. METHODS: Patients were grouped by MCID status (MCID+ vs MCID-). Comparative statistics, ROC analysis, and stepwise logistic regression were used to identify independent preoperative predictors. RESULTS: Mean age was 60.2 years; 64% were male. At 1 year, mean ODI improved from 41.9 to 16.3 (p