Access to care, quality of treatment may help explain survival advantage
Chicago - Black patients admitted to Veterans Affairs (VA) hospitals for treatment of six common medical diagnoses have lower mortality rates than white patients treated for the same illnesses, according to an article in the January 17 issue of The Journal of the American Medical Association (JAMA).
Ashish K. Jha, M.D., and colleagues with the Veterans Affairs Medical Center, and Department of Medicine, University of California, San Francisco, studied racial differences in mortality among patients admitted to hospitals in the VA system. The study included 28,934 white and 7,575 black men admitted to 147 VA hospitals between October 1, 1995, and September 30, 1996, for one of six common medical diagnoses: pneumonia, angina, congestive heart failure, chronic obstructive pulmonary disease, diabetes, and chronic renal failure.
According to background information cited in the study, racial differences are found in many aspects of health care delivery. For example, black patients are less likely to receive coronary angiography after a heart attack than white patients, and after receiving coronary angiography, they are less likely to undergo revascularization. Physicians are more likely to delay referrals to a kidney specialist for black patients than for white patients, blacks are less likely to receive surgery for lung cancer, and black women are less likely to undergo mammography than white women. Most, but not all studies have demonstrated poorer outcomes for blacks.
According to the authors, racial disparities in health care delivery and outcomes may be due to differences in health care access and, therefore, may be mitigated in an equal-access health care system. The VA system is a health care system that potentially offers equal access to care.
The authors compared death rates at 30 days among black and white patients in VA hospitals. They also looked at in-hospital mortality, and mortality at six months.
“We found that black patients had lower 30-day mortality compared with white patients after admission to a VA hospital with one of six common medical diagnoses,” the authors write. “Overall mortality at 30 days was 4.5 percent in black patients and 5.8 percent in white patients. Mortality was lower among blacks for each of the six medical diagnoses.”
“Our findings persisted after adjusting for baseline differences and were consistent across disease, age, financial status, length of stay, comorbidity score and several hospital-level subgroups, including technological capability, region of the country, proportion of treated patients who were black, and urban location,” they continue.
The authors report black patients also had lower adjusted in-hospital and six-month mortality. These findings were consistent among all subgroups evaluated. “For example, among patients aged 65 years or older, blacks had a 24 percent lower 30-day mortality, while among younger patients [patients under the age of 65], blacks had 32 percent lower adjusted mortality risk,” they write. “Blacks had lower 30-day mortality compared with whites among those admitted to hospitals in rural areas and among those admitted to hospitals in urban areas.”
“The survival advantage of black patients is not readily explained; however, the absence of a survival disadvantage for blacks may reflect the benefits of equal access to health care and the quality of inpatient treatment at VA medical centers,” the authors suggest.
(JAMA. 2001; 285:297-303)
Editor’s Note: Study co-author Warren S. Browner, M.D., M.P.H., is currently at the Research Institute, California Pacific Medical Center, San Francisco.
Editorial: The limits of administrative data
In an accompanying editorial, JAMA Contributing Editor David H. Mark, M.D., M.P.H., points out that large databases, such as the VA Patient Treatment Files used in the study by Jha and colleagues, are often limited with respect to assessment of the severity of patients’ illnesses and other potential risk factors.
“What does this suggest for the use of large databases to evaluate health care and the evaluation of results of studies using these databases?” he asks. “First, a certain amount of caution should be applied to the results of studies that use strictly administrative data. Despite advances in risk-adjustment methodology with administrative databases, confounding cannot be ruled out as an explanation of small effect sizes that are nonetheless statistically significant. The study by Jha and colleagues is a rather striking reminder of the magnitude of effect that can be caused by unmeasured confounding. Further study using data that more precisely measure important risk factors for outcome are needed before reaching solid conclusions.”
“Second, continued development of administrative databases that incorporate clinical variables will complement the size of these databases and allow valid research on important clinical and health policy issues that are expected to have small but important effects on patient outcome,” he continues. “Much evidence exists that clinical variables add important predictive ability to administrative data, and that this additional predictive ability makes a difference in assessing factors associated with patient outcomes.”
“Access to and quality of health care are pressing national and international issues that require accurate and unbiased research to inform policy and decision making. It is critical to maintain an awareness of the limits of the data that are used in such research,” he concludes.
(JAMA. 2001; 285:337-338)
Media Advisory: To contact Ashish K. Jha, M.D., call Gene Gibson at 415-750-2250. To contact David H. Mark, M.D., M.P.H., call Jim Michalski at 312-464-5785.
This release is reproduced verbatim and with permission from the American Medical Association as a service to reporters interested in health and behavioral change. For more information about The Journal of the American Medical Association or to obtain a copy of the study, please contact the American Medical Association’s Science News Department at 312-464-5374.
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