Independent Association of Obesity and Nonroutine Discharge Disposition After Elective Anterior Cervical Discectomy and Fusion for Cervical Spondylotic Myelopathy

Abstract

The prevalence of obesity continues to rise in the United States at a disparaging rate. Although previous studies have attempted to identify the influence obesity has on short-term outcomes following elective spine surgery, few studies have assessed the impact on discharge disposition following anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). The aim of this study was to determine whether obesity impacts the hospital management, cost, and discharge disposition after elective ACDF for adult CSM. The National Inpatient Sample database was queried using the International Classification of Diseases, 10th revision, Clinical Modification, coding system to identify all (≥18 years) patients with a primary diagnosis of CSM undergoing an elective ACDF for the years 2016 and 2017. Discharge weights were used to estimate national demographics, Elixhauser comorbidities, complications, length of stay, total cost of admission, and discharge disposition. There were 17,385 patients included in the study, of whom 3035 (17.4%) had obesity (no obesity: 14,350; obesity: 3035). The cohort with obesity had a significantly greater proportion of patients with 3 or more comorbidities compared with the cohort with no obesity (no obesity: 28.1% vs. obesity: 43.5%, P < 0.001). The overall complication rates were greater in the cohort with obesity (no obesity: 10.3% vs. obesity: 14.3%, P= 0.003). On average, the cohort with obesity incurred a total cost of admission $1154 greater than the cost of the cohort with no obesity (no obesity: $19,732 ± 11,605 vs. obesity: $20,886 ± 10,883, P= 0.034) and a significantly greater proportion of nonroutine discharges (no obesity: 16.6% vs. obesity: 24.2%, P < 0.001). In multivariate regression analysis, obesity, age, race, health care coverage, hospital bed size, region, comorbidity, and complication rates all were independently associated with nonroutine discharge disposition. Our study demonstrates that obesity is an independent predictor for nonroutine discharge disposition following elective anterior cervical discectomy and fusion for cervical spondylotic myelopathy.