Temporal changes in the racial gap in survival after in-hospital cardiac arrest

IMPORTANCE: 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. OBJECTIVES: 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. DESIGN, SETTING, AND PARTICIPANTS: 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. EXPOSURE: Race (black or white). MAIN OUTCOMES AND MEASURES: 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. RESULTS: 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. CONCLUSIONS AND RELEVANCE: 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.