The nurses' health study.

Abstract

Initially, one major problem was to define a large population of intelligent, cooperative, and healthconscious women who would be relatively easy to follow. Since the validity of our study is crucially dependent upon a high follow-up rate as well as complete and accurate information regarding various diseases among users and nonusers, we chose registered nurses as study participants. The study population consists of married, female registered nurses born between January 1, 1921 and December 31, 1946, residing in the 11 states with the largest number of state registrants-New York, California, Pennsylvania, Ohio, Massachusetts, New Jersey, Michigan, Texas, Florida, Connecticut, and Maryland. The names and addresses of 238,026 nurses who fulfilled the eligibility criteria were obtained from a file created in 1972 by the American Nurses' Association of all registered nurses in the United States, which includes demographic data on marital status, age, year of graduation, level of education, and whether or not they are practicing their profession. The file was created through state boards of nursing, and permission was obtained by ANA from the boards in the 11 states to release to us only the names and addresses of their instate registrants. They were then assigned unique identification numbers to assure strict confidentiality.