Hospital racial composition: a neglected factor in cardiac arrest survival disparities.

BACKGROUND: Racial disparities in survival after out-of-hospital cardiac arrest have been reported, but their causes remain uncertain. We sought to determine if hospital racial composition accounted for survival differences for patients hospitalized after cardiac arrest.
METHODS: We evaluated hospitalizations of white and black Medicare beneficiaries (2000-2007) admitted from the emergency department to the intensive care unit with a diagnosis of cardiac arrest or ventricular fibrillation. We examined unadjusted survival rates and developed a multivariable logistic regression model that included patient and hospital factors.
RESULTS: We analyzed 68,115 cardiac arrest admissions. Unadjusted survival to hospital discharge was worse for blacks (n = 7,942) compared with whites (n = 60,173) (30% vs 33%, P < .001). In multivariate analyses accounting for patient and hospital factors, adjusted probability of survival was worse for black patients at hospitals with higher proportions of black patients (31%, 95% CI 29%-32%) compared with predominately white hospitals (46%, 95% CI 36%-57%; P = .003). Similarly, whites had worse risk-adjusted survival at hospitals with higher proportions of black patients (28%, 95% CI 27%-30%) compared with predominately white hospitals (32%, 95% CI 31%-33%, P = .006). Blacks were more likely to be admitted to hospitals with low survival rates (23% vs 15%, P < .001).
CONCLUSION: Hospitals with large black patient populations had worse cardiac arrest outcomes than predominantly white hospitals, and blacks were more likely to be admitted to these high-mortality hospitals. Understanding these differences in survival outcomes may uncover the causes for these disparities and lead to improved survival for all cardiac arrest victims.