National trends and regional differences in costs and outcomes of multilevel Anterior Cervical Discectomy and Fusion: 2016-2022

Introduction: Anterior cervical discectomy and fusion (ACDF) is the gold standard for the treatment of degenerative spine disease. Approximately 130,000 ACDFs are performed annually and continue to climb. There is limited literature regarding the regional differences in costs and outcomes in the United States. This study provides a regional, epidemiological overview of multilevel ACDFs to better understand the dynamics of this procedure in the American health system.

Methods: A large national cross-sectional administrative database (Premier Health Database) was queried for patients who underwent multilevel ACDF between January 2016 and June 2022. Patients were divided by census bureau division where their surgery was performed. Total surgical costs, defined as expenses a hospital incurred for the multilevel ACDF procedure, were recorded, and adjusted for inflation. Readmission and reoperation outcomes were also recorded. Average costs and rates of adverse outcomes over time were compared between regions. In a multivariate analysis, adjustments for patient comorbidities, demographics, and time fixed effects were made to isolate regional differences in outcomes and costs referent to the East South Central region.

Results: This study included 178,011 patients (50.6%Female, 11.5%Black, 36.8%Medicare). National 180-day readmission and reoperation rates were 8.1% and 3.2% respectively. Reoperation and readmission rates varied from 7.3-9.5% and 3.0-3.8% regionally. The Pacific had the highest surgical costs ($29,036) while East South Central had the lowest ($17,051). Over time, average surgical costs decreased in the Mountain region (-13.5%) and increased in the Pacific region significantly (+8.6%). In multivariate analysis, all regions had significantly higher surgical costs than the East South-Central region. This increase in costs is accompanied by significantly lower odds of readmission and reoperation in all regions except for New England, West North Central, and Mountain regions.

Conclusion : There is a large regional variation in the cost and outcomes of multilevel ACDF. Since 2016, costs have increased in almost every region with little change in readmission or reoperation rates. After adjusting for comorbidities, most regions that incurred higher costs had statistically significant decreases in rates of reoperation and readmission. Further study into cost categories that are driving the increase in costs of multilevel ACDF is warranted.