Is baseline Neck Disability Index a predictor of 5-year postoperative satisfaction in cervical spondylotic myelopathy? A Spine CORe™ analysis of QOD data

OBJECTIVE: Patient satisfaction is an important outcome to measure quality of care. The hypothesis of this study was that more severe baseline neck disability (Neck Disability Index [NDI] scores 70-100) is associated with less frequent postoperative satisfaction in cervical spondylotic myelopathy. METHODS: This study used the 14-site Spine CORe™ study group's cervical dataset module from the Quality Outcomes Database, which included 1085 patients. Baseline demographics, clinical variables, and surgical parameters were collected. Patient-reported outcomes (PROs) collected include EQ-5D, NDI, and numeric rating scale for neck pain and arm pain scores. Heat maps were created to demonstrate the association of NDI scores with postoperative satisfaction. RESULTS: There were 1085 patients in this study with a 5-year follow-up rate of 83% for the NDI. PROs significantly improved 1 and 5 years postoperatively. Multivariate regression models found baseline NDI scores to be associated with 1- and 5-year satisfaction (OR 0.98 [95% CI 0.97-0.99], p = 0.004). Heat maps were created to determine the significance of baseline, 1-year, and 5-year NDI scores on satisfaction rates. The level of satisfaction decreased with increasing 1- and 5-year NDI scores. Additionally, patients with higher baseline NDI scores required a more significant change in NDI to achieve satisfaction with surgery. CONCLUSIONS: Patients with more severe disability measured by the NDI require a greater change in postoperative NDI scores to meet satisfaction. Despite the importance of postoperative satisfaction, failure to achieve satisfaction should not be assumed to be due to lack of clinical benefit. Discussing a patient's goals and expectations preoperatively is essential to maximize the probability of achieving satisfaction.