In-hospital events and resource utilization associated with percutaneous-based vs. open lumbar fusion, stratified by admission status: a national inpatient sample analysis.

Minimally invasive surgery (MIS) may be associated with a more favorable short-term inpatient profile after lumbar fusion, but whether these associations differ by admission status remains unclear. In this retrospective observational analysis of repeated cross-sectional 2016-2022 National Inpatient Sample (NIS) discharge data, hospitalizations of adults undergoing lumbar fusion were identified and stratified as elective or non-elective. The exposure was defined by the International Classification of Diseases, Tenth Revision, Procedure Coding System-coded approach as percutaneous-based (percutaneous/percutaneous-endoscopic) vs. open fusion. Survey-weighted multivariable logistic regression accounted for the NIS's complex design and adjusted for demographics, hospital characteristics, fusion extent, indication/case-mix, and individual Elixhauser comorbidities; formal approach-by-admission interactions were tested. A total of 174,704 hospitalizations met the inclusion criteria. In elective admissions, percutaneous-based fusion was associated with lower odds of blood product transfusion (aOR 0.448, 95% CI 0.311-0.644), acute posthemorrhagic anemia (aOR 0.591, 95% CI 0.475-0.736), and prolonged length of stay (aOR 0.774, 95% CI 0.656-0.914). In non-elective admissions, it was associated with lower odds of acute posthemorrhagic anemia (aOR 0.669, 95% CI 0.491-0.912) and non-home discharge (aOR 0.666, 95% CI 0.502-0.883). Significant approach-by-admission interactions were observed for blood product transfusion (P = 0.037) and non-home discharge (P = 0.022). These findings indicate that the short-term association profile of percutaneous-based vs. open lumbar fusion differs across admission settings and specific in-hospital measures.