How much do patients benefit in quality of life after surgery for cervical spondylotic myelopathy? A Spine CORe™ analysis of QOD data

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord dysfunction, leading to worsening disability and poor quality of life. The long-term benefits of surgery for patient quality of life remain incompletely defined. Given the current emphasis on value-based care, this study aimed to identify 1) how surgery improves quality of life and 2) what factors are associated with quality of life improvement in patients operated on for CSM. METHODS: The Spine CORe™ study group performed a post hoc analysis of the prospectively collected, 14-site Quality Outcomes Database CSM cohort. The primary outcome was the 5-dimension EuroQol-5 (EQ-5D) score, assessed at baseline and at 3, 12, 24, and 60 months postoperatively. The minimal clinically important difference (MCID) for the EQ-5D score was defined as 0.11. A multivariable logistic model was used to identify preoperative factors associated with the MCID for the 60-month EQ-5D score, controlling for variables reaching a p value < 0.20 on univariate analysis. Quality-adjusted life years (QALYs) gained were also calculated using the area under the curve method, with baseline projected QALYs subtracted from observed values. RESULTS: At 60 months, follow-up status was available for 895 of 1085 patients (82.4%). A total of 788 patients had EQ-5D scores recorded at 60 months for inclusion in the initial phase of this analysis. The mean EQ-5D score improved significantly from 0.58 ± 0.22 at baseline to 0.76 ± 0.22 at 60 months (p < 0.001), with gains evident by 3 months and sustained through all subsequent follow-up intervals. At 60 months, 58.7% of patients achieved the EQ-5D MCID. Multivariable analysis identified greater baseline numeric rating scale neck pain score and use of anterior cervical corpectomy and fusion (ACCF) as independent predictors of decreased odds of MCID achievement (p < 0.05). Conversely, lower baseline EQ-5D scores, corresponding to worse quality of life, were associated with increased odds of improvement (p < 0.05). The authors further found in the full cohort of patients that there was a mean QALY gain of 0.72 ± 1.11 following surgery. CONCLUSIONS: Patients undergoing surgery for CSM experience significant and durable postoperative improvements in their quality of life, with notable gains of 0.72 QALYs achieved 5 years after surgery. Additionally, more than 50% of patients achieve a clinically meaningful benefit in EQ-5D score at 5 years. Greater baseline neck pain severity and ACCF were associated with reduced odds of achieving the MCID, whereas worse baseline quality of life was associated with greater odds of achieving long-term improvement. Overall, these findings confirm that surgery for CSM yields sustained quality of life benefits for the majority of patients.