1039 How Many Quality-Adjusted Life Years Do Patients Operated for CSM Gain?

INTRODUCTION: Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord dysfunction and leads to worsening disability and poor quality of life. The long-term benefits of surgery for patient quality of life remain incompletely defined. METHODS: We analyzed the prospectively collected Quality Outcomes Database CSM cohort. EuroQol-5D (EQ-5D) scores, measuring quality of life, were compared 24 months postoperatively. Lifetime Quality-Adjusted Life Years (QALYs) gained were calculated by using the following formula, (Qi-Q) * (1-e^(-r*L)) / r, where Qi-Q represents the difference in EQ-5D after intervention, L is the residual life expectancy, and r denotes the discount rate. A multivariable logistic model was used to identify preoperative factors associated with achieving minimum clinically important difference (MCID) for 24-month QALY (>= 0.149), controlling for variables reaching p<0.20 on univariate analysis. RESULTS: Of the 1141 total patients, 894 (80.8% excluding deceased patients) had EQ-5D recorded at 24 months. 75% (n=670) of these patients with 2-year follow-up data experienced improvement in EQ-5D score, with mean values significantly higher at 24-months compared to baseline (0.73 vs 0.57; p<0.001). Mean lifetime QALY gained was 4.79. On multivariate analysis, higher baseline neck pain visual analog scale values (OR 0.88 95% CI 0.81-0.94; p=0.018) and EQ-5D scores (OR 0.002 95% CI 0.0007-0.006; p=<0.001) reduced odds of achieving MCID for QALYs gained following CSM surgery. CONCLUSIONS: Seventy-five percent of patients undergoing surgery for CSM experience postoperative improvements in their quality of life (EQ-5D). CSM patients undergoing surgery gain nearly five-lifetime QALYs. Patients with baseline lower neck pain scores and worse quality of life are most likely to gain meaningful increases (MCID) in QALYs following CSM surgery.