Black Mortality Gap: Causes Still Elusive : Health: Equal incomes and quality medical care would still leave minorities with a much higher rate of premature deaths, researchers conclude.

The high rate of premature deaths among black Americans is the result of so many different causes that even if high quality health care were equally available to whites and blacks and incomes were equal, 31% of the gap would remain, according to a study being published today.

In a 13-year survey of some 8,806 black and white adults, researchers at the federal Centers for Disease Control in Atlanta found that just under one-third of the difference in death rates between the races--which are 149% higher for blacks between the ages of 35-54 than whites--can be attributed to the higher incidence of preventable risk factors such as high blood pressure, cholesterol level, weight, smoking, alcohol intake and diabetes.

If blacks and whites were equal in all these risk factors but not in income, the study found, 69% of the difference in mortality rate would remain.

Differences in income, the study found, accounted for 38 of those 69 percentage points. In other words, if black and white samples were chosen from groups with equal incomes, that one factor would erase 38% of the mortality difference.

Poverty, which afflicts blacks disproportionately, is known to limit access to health care and, the researchers noted, may contribute to a disease by imposing greater stress.

A final 31% of the mortality difference could not be attributed to any known or measurable cause. Among such factors are presumed to be differences in environment, heredity and life style.

The study, published in the Journal of the American Medical Assn., appears to complicate the already difficult question of why the health of black Americans appears to be steadily deteriorating relative to whites.

For example, in 1986--the last year for which figures are available--black life expectancy declined for the second year in a row, falling to 69.4 years, 5.4 year less than the average white life expectancy.

By giving broad weight to economic factors--which it says account for 38% of the difference in black and white death rates--and other unknown considerations, the study appears to suggest that only part of the solution to the mortality gap may lie within the power of the medical community.

“Broader social and health system changes and research targeted at the causes of the mortality gap, coupled with increased efforts aimed at modifiable risk factors, may all be needed for egalitarian goals in health to be realized,” the study stated.

The study compared the health profiles and histories of 7,573 whites and 1,233 blacks taken from health surveys conducted from 1971 to 1975 and then again from 1982 through 1984.