Race and ethnicity in the intensive care unit: what do we know and where are we going?

T here is a considerable body of research examining the influence of race and ethnicity on the delivery and outcomes of critical care. Initially, some of these reports seemed incongruous. For example, some studies reported that black patients receive fewer medical interventions, (1, 2) have shorter lengths of stay and use fewer resources (2), whereas others found increased resource use including more intensive care unit (ICU) admissions and medical interventions for minorities as compared with white patients (3, 4). There has also been mixed results regarding the influence of race/ethnicity on ICU survival (3, 4). However, recently there is an emerging picture that seems clear and consistent. In this issue of Critical Care Medicine, Erickson and colleagues (5) examined the relationship between race/ethnicity and ICU care in a multicenter study involving 35 California hospitals and helps add to this emerging picture of the role of race/ ethnicity in ICU care and outcomes. The authors found higher mortality among black patients than white patients; however, after adjusting for severity of illness, there was no difference in mortality. This is congruent with previous studies. For example, Williams and colleagues (2) showed that although there was more ICU resource use among white patients, there was no difference in severityadjusted mortality between black and white patients. However, Erickson and colleagues also showed that there are important disparities: critically ill black patients had higher acute severity of illness on admission to the ICU than critically ill white patients. Similar disparities have been found in specific critical illnesses, including pneumonia, sepsis, and acute lung injury (6 – 8). Although these studies suggest that severityadjusted outcomes of critical illness are not worse for racial minorities, we cannot ignore that minorities present to the ICU with more severe illness. Hence, severity of illness on admission is an important clarifying factor in understanding specific mechanisms in racial and ethnic differences and disparities. A second important clarifying factor in understanding these disparities in critical care has emerged through the work of Barnato and colleagues (6, 7). There are important differences in care received by racial minorities as a result of differences in the quality of care provided by hospitals that care for predominantly minority patients such as the poorly funded “safetynet” hospitals. This explanation likely accounts for some of the variation in care across racial and ethnic groups seen in other studies and highlights the fact that eliminating disparities will require a broad scope, including examining our regional systems for health care. A third important clarifying factor is differentiating care for patients likely to survive the ICU from end-of-life care in the ICU. The ICU is a common site for the delivery of end-of-life care (9), which differs substantially from ICU care of patients with a high probability of survival. End-of-life care is much more likely to be influenced by patient and surrogate preferences. The goals of care at the end of life often shift from prolonging life to ensuring comfort, and the way this shift is made is often powerfully influenced by race, ethnicity, and culture (10). Importantly, survival is only minimally prolonged (if it is prolonged at all) by using a higher intensity of care at the end of life (11). Nonetheless, patient and surrogate preferences play an enormous role in how these decisions are made. Unfortunately, identifying terminal hospitalizations at admission is difficult and likely will always be so. Prognostic indices assign a probability based on groups of patients, whereas the individual patient experiences a single outcome. Erickson and colleagues tried to assess the role of preferences about end-of-life care by controlling for patients with do-not-resuscitate orders on admission, but do-not-resuscitate status on admission was not an important predictor of racial differences (5). However, do-not-resuscitate status on ICU admission represents one end of the spectrum of preferences for life-sustaining treatments and does not account for changes in goals of care during the ICU stay. Separating end-of-life care and the role of patient and family preferences for end-of-life care from care for patients who are likely to survive the ICU may help elucidate differences in ICU care among racial and ethnic groups. We know there are important racial differences in end-of-life care in the ICU (12). We do not know to what extent these differences are the result of the preferences of informed patients and to what extent they are the result of disparities in end-of-life care. An additional area of need in disparities research concerns the outcomes of critical care. Most of the research on racial/ethnic differences has focused on short-term mortality and acute physiology. This narrow approach ignores important patient-centered long-term outcomes such as healthrelated quality of life, including physical, mental, and social morbidity and function after critical care. Prior research has shown higher levels of posttraumatic distress in minority patients after hospitalization for trauma (13) but beyond this, we know little about racial and ethnic differences and disparities in long-term outcomes of intensive care and such exploration may reveal important targets for future interventions. Research has documented the existence of important health and healthcare disparities across many fields (14). Descriptive studies thus far dominate health disparities research. These studies have made important contributions to the cur*See also p. 429.