National vital event data published by the Indian Health Service (IHS) prior to the early 1990s suggest that cardiovascular disease (CVD) mortality rates (for example, for heart attack and stroke) are lower for American Indians and Alaska Natives (AIAN). This finding is somewhat puzzling, given that American Indians have for years had some of the Nation's highest rates of major CVD risk factors, such as smoking, diabetes, and obesity.
In a recent study, Dorothy A. Rhoades, M.D., M.P.H., of the University of Colorado Health Sciences Center, adjusted for racial misclassification in the IHS data (something that was not done by the IHS until the early 1990s) and concluded quite the opposite. She found that AIAN have higher CVD mortality rates than the rest of the U.S. population, and these rates may have been higher for more than a decade.
Furthermore, CVD mortality is increasing among AIAN but decreasing in the general population widening a previously unrecognized disparity, notes Dr. Rhoades. She used IHS vital event data to compare trends in CVD mortality from 1989-1991 to 1996-1998 among three U.S. population groups: AIAN, all races, and whites.
After adjusting for age and racial misclassification, by 1996-1998, the number of CVD deaths per 100,000 among AIAN was 195.9 compared with 166.1 and 159.1 for all races and whites, respectively. The annual percent change in CVD mortality for AIAN was 0.5, a slight increase, compared with -1.8, a decline, in the other groups. The most striking and widening disparities were found for middle-aged AIAN, but CVD mortality among elderly AIAN was lower than in the other groups. Efforts to reduce CVD mortality in AIAN must begin before the onset of middle age, concludes Dr. Rhoades. Her work was supported in part by the Agency for Healthcare Research and Quality (HS10854).
See "Racial misclassification and disparities in cardiovascular disease among American Indians and Alaska Natives," by Dr. Rhoades, in the March 15, 2005, Circulation 111, pp. 1250-1256.