Temporal Changes in the Racial Gap in Survival After In-Hospital Cardiac Arrest

Abstract

Previous studies have found marked differences in survival after in-hospital cardiac arrest by race. Whether racial differences in survival have narrowed as overall survival has improved remains unknown. To examine whether racial differences in survival after in-hospital cardiac arrest have narrowed over time and if such differences could be explained by acute resuscitation survival, postresuscitation survival, and/or greater temporal improvement in survival at hospitals with higher proportions of black patients. In this cohort study from Get With the Guidelines-Resuscitation, performed from January 1, 2000, through December 31, 2014, a total of 112 139 patients with in-hospital cardiac arrest who were hospitalized in intensive care units or general inpatient units were studied. Data analysis was performed from April 7, 2015, to May 24, 2017. Race (black or white). The primary outcome was survival to discharge. Secondary outcomes were acute resuscitation survival and postresuscitation survival. Multivariable hierarchical (2-level) regression models were used to calculate calendar-year rates of survival for black and white patients after adjusting for baseline characteristics. Among 112 139 patients with in-hospital cardiac arrest, 30 241 (27.0%) were black (mean [SD] age, 61.6 [16.4] years) and 81 898 (73.0%) were white (mean [SD] age, 67.5 [15.2] years). Risk-adjusted survival improved over time in black (11.3% in 2000 and 21.4% in 2014) and white patients (15.8% in 2000 and 23.2% in 2014; P for trend <.001 for both), with greater survival improvement among black patients on an absolute (P for trend = .02) and relative scale (P for interaction = .01). A reduction in survival differences between black and white patients was attributable to elimination of racial differences in acute resuscitation survival (black individuals: 44.7% in 2000 and 64.1% in 2014; white individuals: 47.1% in 2000 and 64.0% in 2014; P for interaction <.001). Compared with hospitals with fewer black patients, hospitals with a higher proportion of black patients with in-hospital cardiac arrest achieved larger survival gains over time. A substantial reduction in racial differences in survival after in-hospital cardiac arrest has occurred that has been largely mediated by elimination of racial differences in acute resuscitation survival and greater survival improvement at hospitals with a higher proportion of black patients. Further understanding of the mechanisms of this improvement could provide novel insights for the elimination of racial differences in survival for other conditions.