Abstract
Study Design: Analysis of prospectively collected data. Objective: To assess if systemic illness severity affects cervical spondylotic myelopathy (CSM) surgery outcomes. Summary of Background Data: It remains unclear if CSM patients with poor physical status/severe systemic illness benefit as much from surgery as those in good condition. Methods: Using the Quality Outcomes Database CSM cohort and the American Association of Anesthesiology (ASA) grade as a surrogate for illness burden, we compared patients with (ASA 3-4) and without (ASA 1-2) severe systemic illness, including rates of readmission and 24-month minimal clinically important differences (MCID) achievement for patient-reported outcomes (PROs)-numerical rating score (NRS) arm and neck pain, neck pain-related disability (NDI), and quality of life (EQ-5D). Results: Of 1141 CSM patients, 1062 had ASA grades recorded. Of these 1062 patients, 70.2% had a 2-year follow-up for mJOA, and 81%-84% had a follow-up for NRS arm and neck, NDI, and EQ-5D. Five hundred twenty-one patients (49.1%) had mild (ASA 1-2) and 541 (50.9%) had severe systemic illness (ASA 3-4). The severe disease cohort was older (63.3 +/- 11.0 vs. 57.4 +/- 11.7), had higher BMI (31.4 +/- 7.0 vs. 28.9 +/- 5.6), had more comorbidities (diabetes, coronary artery disease, depression), and had less independent ambulation (71.3% vs. 90.6%) (P<0.05). At baseline, severe disease patients had worse NRS arm (5.2 +/- 3.5 vs. 4.7 +/- 3.4) and neck (5.5 +/- 3.2 vs. 5.1 +/- 3.3) pain, NDI (40.5 +/- 20.1 vs. 36.8 +/- 21.0), and EQ-5D (0.53 +/- 0.22 vs. 0.59 +/- 0.22) scores (P<0.05). Perioperatively, the severe disease cohort had longer hospitalizations (2.4 +/- 2.6 vs. 1.7 +/- 2.0 days) and increased nonhome discharges (17% vs. 5%) (P<0.05).The severe disease cohort had higher 90-day readmissions (7.6% vs. 2.5%), including surgery-related (3.7% vs. 1.5%) and non-surgery-related reasons (3.9% vs. 1.0%) (P<0.05). On multivariate analysis, increased ASA grade was significantly associated with 90-day readmissions (OR: 2.55 per 1-grade increase, 95% CI: 1.38-4.83). However, both severe and mild disease cohorts had similarly high rates of achieving 2-year MCID for mJOA (67.5% vs. 66.0%), NRS arm (72.0% vs. 74.1%), neck (69.5% vs. 69.4%) pain, NDI (63.1% vs. 68.1%), and EQ-5D (67.9% vs. 66.9%) (P>0.05). Conclusion: Patients with severe systemic illness (higher ASA) have worse baseline PROs and higher 90-day readmissions. However, they achieve similar MCID rates for mJOA and all measured PROs 2 years postoperatively.