Migration out of Evans County, Georgia, was sizeable and, in an 87 month follow-up period, amounted to 14% of the cohort originally examined for the cardiovascular survey of 1960-1962. Migration was selective of young individuals and differentially selective of blacks for long-distance moves out of Georgia, and selective of whites for short-distance migration. There was no evidence of significant migration selection on the coronary heart disease risk factors of blood pressure and cholesterol adjusting for the age, race, and sex of migrants.
Wetherbee H, Tyroler HA. The Relation of Migration to Coronary Heart Disease Risk Factors. Arch Intern Med. 1971;128(6):976-981. doi:10.1001/archinte.1971.00310240130017