Keys gathered data on heart disease and its potential causes from nearly 13,000 men in Greece, Italy, Croatia, Serbia, Japan, Finland, the Netherlands and the United States.

凯斯从希腊、意大利、克罗地亚、塞尔维亚、日本、芬兰、荷兰和美国的近1.3万名男性中收集了心脏病及其潜在病因的数据。