Is Thirty‐Day Hospital Mortality Really Lower for Black Veterans Compared with White Veterans?

Abstract

Objective. To examine the source of observed lower risk-adjusted mortality for blacks than whites within the Veterans Affairs (VA) system by accounting for hospital site where treated, potential under-reporting of black deaths, discretion on hospital admission, quality improvement efforts, and interactions by age group. Data Sources. Data are from the VA Patient Treatment File on 406,550 hospitalizations of veterans admitted with a principal diagnosis of acute myocardial infarction, stroke, hip fracture, gastrointestinal bleeding, congestive heart failure, or pneumonia between 1996 and 2002. Information on deaths was obtained from the VA Beneficiary Identification Record Locator System and the National Death Index. Study Design. This was a retrospective observational study of hospitalizations throughout the VA system nationally. The primary outcome studied was all-location mortality within 30 days of hospital admission. The key study variable was whether a patient was black or white. Principal Findings. For each of the six study conditions, unadjusted 30-day mortality rates were significantly lower for blacks than for whites ( po.01). These results did not vary after adjusting for hospital site where treated, more complete ascertainment of deaths, and in comparing results for conditions for which hospital admission is discretionary versus nondiscretionary. There were also no significant changes in the degree of difference by race in mortality by race following quality improvement efforts within VA. Risk-adjusted mortality was consistently lower for blacks than for whites only within the population of veterans over age 65. Conclusions. Black veterans have significantly lower 30-day mortality than white veterans for six common, high severity conditions, but this is generally limited to veterans over age 65. This differential by age suggests that it is unlikely that lower 30-day mortality rates among blacks within VA are driven by treatment differences by race.

Differences in Short-Term Versus Long-Term Outcomes of Older Black Versus White Patients With Myocardial Infarction

“…Several prior analyses have found similar results of a short-term survival advantage among blacks compared with whites for cardiac and noncardiac conditions. [13][14][15]24,25 One possibility for these findings in black patients may be the higher prevalence of type 2 or secondary MIs seen in the setting of renal failure or hypertensive disease. These MIs are caused by increased oxygen demand or decreased oxygen supply rather than acute plaque rupture 26 and are often associated with smaller infarct size and less myocardial damage as evidenced by lower troponin elevations.…”

“…differences in short-term survival may also reflect a "survivor effect" in which blacks who survive to age 65 may represent a healthier cohort of patients than white patients of the same age. [13][14][15] It is also unknown whether black patients with larger MIs may be more likely to die before reaching the hospital; therefore, those blacks who are admitted may have less severe disease than whites. In addition to age and sex, there are likely additional unmeasured differences between these groups that confer a protective benefit toward black patients that we have not fully captured or adjusted for.…”

Trends and Survival Between Ethnic Groups After Stroke

“…13 However, the current study has advantages of larger sample size (n=4212), longer follow-up (16 years), and using self-defined ethnic groups BC and BA instead of 1 black group in the previous study. 4,22 Potential reasons for explaining survival advantage of black over white include differences in case mix and stroke subtypes, 15 survivorship and selection bias, 23 different methods of risk adjustment, 24 different lengths of outcome assessment, 25 and differential receipt of effective interventions.…”

Differential Impact of Longitudinal Medication Non-Adherence on Mortality by Race/Ethnicity among Veterans with Diabetes

“…19 Lower mortality among NHB compared to NHW veterans has also been reported in other diseases. 20,21 The exact reasons for these differences are unclear and need to be further studied. However, we can offer the following potential brief explanations: that there are more intensive efforts at treatment and monitoring to improve control, use of more social-professional support, and survivor bias among NHB veterans; or greater likelihood of dual use with more fragmented care and tighter glycemic control with poorer outcomes among NHW veterans.…”