Inpatient Mortality in Emergency Care: Is Competition Always Good?

The objective of this study was to measure the association between regional competition and emergency care outcomes. Competition was measured using the Herfindahl-Hirschman Index for three hospital referral regions in Maryland. Preliminary regression analysis using a logistic binary model showed that higher competition was associated with lower odds of mortality. Further investigation suggested that competition could be endogenous. Further regression analysis using an instrumental variable of hospital system affiliation and two-stage least squares estimation showed that lower competition was associated with lower odds of mortality for sepsis and trauma (OR = 0.7, p-value <0.001, OR = 0.5, p-value