Coronary Calcium and Events in Four Ethnic Groups

To the Editor: In their report on coronary calcium and coronary events in four ethnic groups, Detrano et al. (March 27 issue) 1 grouped persons by ethnicity but did not provide any proof that these persons were ethnically similar or offer an operational definition of ethnicity. An unbiased reader may suspect that multiple populations exist within each of these ethnic groups, and the conclusions of the study do not account for such population stratification. A better approach would be to devise a test that demonstrates that persons are similar on some basis related to ethnic background. One possible approach is to . . .