Study is the first to track changes in the rate of ICD utilization among blacks and whites

Jan 4 2005

Racial disparities in the use of implantable cardioverter-defibrillators (ICDs) declined during the 1990s as use of the devices spread into communities with larger African-American populations, according to a new study in the Jan. 4, 2005 issue of the Journal of the American College of Cardiology.

“One thing we need to do as a society is to improve the performance of hospitals caring for large numbers of black patients. Our data suggest that black patients were disadvantaged because they happened to receive care at hospitals where ICDs were less available,” said Peter W. Groeneveld, M.D., M.S.

Dr. Groeneveld and colleagues at the Veterans Affairs Medical Center, the University of Pennsylvania, and the Leonard Davis Institute of Health Economics in Philadelphia, the Veterans Affairs Palo Alto Health Care System, Stanford University and National Bureau of Economic Research in Stanford, California, reviewed Medicare claims data to track the use of ICDs from 1990 to 2000. Implantable cardioverter-defibrillators are small devices implanted under the skin to monitor heart rhythms and deliver electrical shocks to interrupt life-threatening arrhythmias.

“White-black disparity in the use of the implantable cardioverter defibrillator significantly improved over the 1990s, from an odds ratio of 0.52 to 0.69, indicating a 33 percent reduction in the inequality observed in the early 1990s. However, a substantial disparity remained by the end of the decade. One of the significant factors in the improvement seems to be the increased use of ICDs in non-academic hospitals located in areas with larger local black populations,” Dr. Groeneveld said.

“It is both encouraging that there was improvement and dismaying that the gap persisted, particularly since increased attention has been paid in the medical literature and by national health care organizations to racial disparities in health care,” he added.

Dr. Groeneveld said the findings of this study support the potential value of proposed “payment for quality” policies. Under such a system, health care providers would need to document that they were using appropriate procedures and meeting quality-of-care measures in order to receive full reimbursements.

While Medicare data has the advantage of capturing most major medical procedures performed on patients 65 and older and some information on individual characteristics of these patients, the data does not include detailed clinical data.

“This is, of course, observational data, thus it is difficult to ascribe causality to the correlations we observed. We do think that the preponderance of evidence from this study as well as other studies suggests the mechanism of increased ICD penetration into high-minority areas leading to decreased disparities is likely to be correct,” Dr. Groeneveld said.

In an editorial in the journal, John S. Rumsfeld, M.D., Ph.D., at the Denver Veterans Affairs Medical Center/University of Colorado Health Sciences Center, and Eric D. Peterson, M.D., M.P.H., at Duke University Medical Center, Durham, North Carolina, wrote that this study “helps us take a step forward in our understanding of racial disparities.”

“This study moves beyond mere description of differences, and suggests a possible explanation for these differences. As ICDs diffused into regions with a higher proportion of African-Americans over time, the racial gap in treatment closed to some degree. This raises the possibility that if technology can be more rapidly diffused throughout geographic regions, we may see less racial disparity,” Dr. Rumsfeld said.

He said the results suggest that quality improvement and evidence-based medicine offer strategies for fighting racial disparities in health care.

“We should take the results of studies like this one and move toward improved diffusion of technologies like ICDs to eliminate racial disparities. The mechanism for making this happen may be right in front of us – through quality improvement programs and initiatives in which care decisions are evidence-based and not race-based,” Dr. Rumsfeld said.

Nancy R. Kressin, Ph.D., at the VA Center for Health Quality, Outcomes, and Economic Research in Bedford, Massachusetts, and the Boston University School of Public Health, who was not connected to this study, commented that it adds an important new perspective on racial disparities in cardiac care.

“This study's findings also point to a potential remedy for racial disparities in care: increase the provision of high quality care for everyone and disparities may lessen. In a field where very few causal mechanisms or points of intervention have been identified, this study's results provide one suggested direction for policy makers, administrators, and clinicians to pursue to decrease racial disparities in care. These findings provide evidence that improvements in care are an achievable goal and that while disparities in care were not eliminated by the end of the study period, substantial decreases in disparities were achieved,” Dr. Kressin said.