Volume and outcomes in posterior cervical fusion: Insights from a national inpatient analysis

Hospital procedural volume is often linked to outcomes and costs, but whether this relationship holds for posterior cervical fusion (PCF) remains unclear.

The objective of this study was to evaluate whether hospital PCF volume is associated with complications, discharge disposition, and hospital costs.

Retrospective cross-sectional analysis of the National Inpatient Sample (NIS) from 2016 to 2022.

Elective PCF encounters were analyzed, with hospitals stratified by annual PCF volume (low, intermediate, high). Survey-weighted multivariable logistic regression estimated odds of cardiovascular complications, overall adverse events, and nonroutine discharge; linear regression assessed total costs and lengths of stay (LOS). Models adjusted for demographic, clinical, and hospital covariates.

Survey-weighted regression with odds ratios (ORs), coefficients, and 95% confidence intervals (CIs). Significance was set at P < 0.05.

We included 163,230 weighted elective PCF cases. Baseline characteristics differed across volume groups (P < 0.001) except for sex (P = 0.163). Compared with low-volume hospitals, high-volume hospitals had higher odds of cardiovascular complications (OR 1.87, 95% CI 1.70-2.06, P < 0.001), overall adverse events (OR 1.30, 95% CI 1.21-1.40, P < 0.001), and non-routine discharge (OR 1.09, 95% CI 1.02-1.16, P = 0.008). High-volume hospitals were also associated with higher total costs (coefficient: $4298; 95% CI $3468-$5128; P < 0.001), with no significant difference in LOS (P = 0.387).

Hospital PCF volume is tied to complications, nonroutine discharges, and higher costs, challenging the volume-outcome paradigm and underscoring adjustment for patient complexity and case mix in benchmarking and allocation.