The impact of interhospital competition on treatment strategy and outcomes for unruptured intracranial aneurysms

Abstract

BACKGROUND: Interhospital competition has been shown to affect surgical outcomes and expenditures. However, interhospital competition's impact on neurosurgery is poorly characterized. OBJECTIVE: To assess how interhospital competition is associated with treatment strategy and outcomes for unruptured intracranial aneurysms (UIAs). METHODS: We identified all elective UIA admissions in the National Inpatient Sample from 2002 to 2011. Competitive intensity of each hospital market was quantified using the validated Herfindahl-Hirschman Index (HHI), with lower values denoting higher competition. We then obtained nationwide HHI values for 2012 to 2016 from the Health Care Cost Project. Outcomes included treatment modality (clipping, coiling, or nonoperative management), inpatient mortality, disposition, complications, length of stay (LOS), and costs. Multivariate regression assessed the association between HHI and outcomes, controlling for patient demographics, severity metrics, hospital characteristics, and treatment. RESULTS: We studied 157 979 elective UIA admissions at 1435 hospitals from 2002 to 2011, with an increase in coiling admissions (13.4% to 33.7%) and decrease in clipping admissions (30.9% to 17.6%). Mean hospital HHI was 0.11 (range = 0.001-0.97). Competition decreased for 61.8% of hospitals from 2002 to 2011 and 68.1% of metropolitan localities from 2012 to 2016. Admissions in more competitive hospital markets exhibited increased odds of undergoing surgery (odds ratio [OR] = 1.37, P