Rates of Mortality in Cervical Spine Surgical Procedures and Factors Associated With Its Occurrence Over a 10-Year Period: A Study of 342 477 Patients on the Nationwide Inpatient Sample.

BACKGROUND: Risk of death is important in counseling patients and improving quality of care. Incidence of death in cervical surgery is not firmly established due to its rarity and limited sample sizes, particularly in the context of different surgeries, demographics, and risk factors. Particularly, different patient risk profiles may have varying degrees of risk in terms of surgeries, comorbidities, and demographics. This study aims to use a large patient cohort available on a national database to study the prevalence of death associated with cervical spine surgery.
METHODS: This study was a retrospective review of the Nationwide Inpatient Sample (NIS) years 2003-2012. A total of 342 477 patients were identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes undergoing spinal fusion or decompression for disc degeneration, stenosis, spondylosis, myelopathy, postlaminectomy syndrome, scoliosis, or neck pain associated with the cervical region. Patients with malignancy were excluded from analysis. Incidence of mortality was assessed by χ2 tests across different patient demographics and comorbidities, procedures performed, and concurrent in-hospital complications. Binary logistic regression identified significant increases or decreases in risk of death while controlling for comorbidities, race, sex, and Mirza invasiveness. Significance was defined as P < .05 differences relative to overall cohort.
RESULTS: The study analyzed 342 477 patients with an overall mortality rate of 0.32%. A total of 231 977 simple fusions (single approach and <3 levels) experienced a mortality rate of 0.256%; 49 594 complex fusions (combined approach or ≥3 levels) had a mortality rate of 0.534%; and 61 285 decompression-only procedures reported a 0.424% mortality rate, all P < .001 from overall rate. In reporting rates across different demographics, male patients experienced a significantly higher risk for mortality (odds ratio [OR], 2.16; 95% CI, 1.87-4.49), as did black patients (OR, 1.58; CI, 1.32-1.90) and patients over age 75 (OR, 7.55; 95% CI, 6.58-8.65), all P < .001. Patients with liver disease reported 6.40% mortality. Similarly, patients with congestive heart failure (3.91%), cerebrovascular disease (3.41%), and paraplegia (3.79%) experienced high mortality rates, all in cohorts of over 2000 patients, all P < .001. Concurrent in-hospital complications with the highest risk of mortality were shock (OR, 51.41; 95% CI, 24.08-109.76), pulmonary embolism (OR, 25.01; 95% CI, 14.70-42.56), and adult respiratory distress disorder (OR, 14.94; 95% CI, 12.75-17.52), all P < .001.
CONCLUSION: In 342 477 cervical spine surgery patients an overall mortality rate of 0.32% was reported. The rate was 3.91% in a cohort of 5933 patients with congestive heart failure and 3.79% in a cohort of 6947 patients with paraplegia. These findings are consistent with previous estimates and may help counsel patients and improve in-hospital safety. LEVEL OF EVIDENCE: 3.