Differences in survival between black and white patients after in-hospital cardiac arrest appear to have decreased, according to a recent study.
Researchers performed a cohort study of data from Get With the Guidelines-Resuscitation to determine whether racial differences in survival after in-hospital cardiac arrest have improved and to examine the factors that may be associated with such improvements. Data from Jan. 1, 2000, through Dec. 31, 2014, were included for patients who had a cardiac arrest in the hospital and who were cared for in general inpatient units or in ICUs. Survival to discharge was the primary outcome; secondary outcomes were acute resuscitation survival and postresuscitation survival. Calendar-year rates of survival by race were calculated after adjustment for characteristics at baseline. The study results were published online Aug. 9 by JAMA Cardiology.
A total of 112,139 patients from 289 hospitals were included in the current study. Of these, 30,241 (27.0%) were black and 81,898 (73.0%) were white. The mean age was 61.6 years for black patients and 67.5 years for white patients. Both black and white patients demonstrated improvements in risk-adjusted survival over time (11.3% and 15.8% in 2000 vs. 21.4% and 23.2% in 2014, respectively; P<0.001 for trend for both). However, survival improvement was more pronounced in black patients than in white patients. The reduced survival difference by race appeared to be linked to elimination of racial differences in survival of acute resuscitation (44.7% in 2000 vs. 64.1% in 2014 for black patients and 47.1% in 2000 vs. 64.0% in 2014 for white patients; P<0.001 for interaction). However, racial differences in postresuscitation survival persisted. Survival gains over time were larger in hospitals where a higher proportion of black patients had an in-hospital cardiac arrest versus hospitals where fewer black patients did.
The study authors noted that their study included only hospitals that participated in Get With the Guidelines-Resuscitation and that their results may not be generalizable to other hospitals. In addition, they noted that information on race was self-reported and that residual confounding and an increase in do-not-resuscitate orders during the study period could have affected their findings, among other limitations. However, they concluded that racial differences in survival after in-hospital cardiac arrest decreased significantly over time, mostly because of elimination of differences in acute resuscitation survival and increased improvement in hospitals with more black patients. “Further understanding the mechanisms of that improvement could provide novel insights for the elimination of racial differences in survival for other conditions,” the authors wrote.
The authors of an accompanying comment agreed that hospitals participating in Get With the Guidelines-Resuscitation are not likely to represent all U.S. hospitals and also mentioned the increase in do-not-resuscitate orders, along with an increase in rapid response teams, as a potential contributor to the study results. In addition, they noted that some of the examined parameters in the medical record may have been subject to recall bias. While the study results are good news, the mechanism behind the improvement “remains unclear and should be a priority for research in the coming decade,” they wrote. “As a nation, we still need data on cardiac arrest incidence and survival that is uniformly collected, with clear attention to changes in factors that may influence survival rate as a reflection of changes in the population under study.”