This study tested the hypothesis that there are differences between whites and blacks with regard to the frequency and types of antibiotics used. Because of their high prescription rate and stability, as well as the fact that they are not available over-the-counter, systemic antibiotics are useful indicators of racial differences in overall patterns of medication use.

Data were collected from subjects enrolled in the Minnesota Heart Survey, which consisted of two probability samples of residents in the Twin Cities metropolitan area in 1980-1982 and in 1985-1987. Subjects were asked to report on medication use, including antibiotic medication use.

Statistically significant racial differences in the prevalence of antibiotic use were found for several demographic and diagnostic categories. In sum, when there were racial differences, whites reported higher rates of antibiotic use. After age adjustment, 22% of whites and 17% of blacks used antibiotics. Adjusted for age, the race and gender results were as follows: 15% of black men, 18% of white men, 18% of black women, and 26% of white women used antibiotics. With regard to specific types of antibiotics, white men reported greater use of penicillin, erythromycins, and cephalosporin in the year preceding the survey. Black men were more than twice as likely to report sulfa use (despite the fact that sulfa drugs are contraindicated in the presence of glucose-6-phosphate deficiency, an inborn error of metabolism that affects 10% of U.S. black men). White women were more likely to reported use for all drug classes.

The authors state that this difference in antibiotic medication use is probably not explained by differences in healthcare utilization, as the average annual number of physician visits in the U.S. was similar for all racial groups from 1978 to 1980 (according to the Report of the Secretary's Task Force on Black and Minority Health, 1985). The authors note that it is not possible to determine from these data if these differences reflected only patient compliance with having prescriptions filled or taking the medications. Other possible explanations were not offered, but the authors do caution that it is important to determine whether these patterns are consistent for other types of medications and conclude that the observed differences "may influence overall health by increasing or prolonging morbidity, thereby increasing healthcare costs overall."