The Danish Nurse Cohort was initiated in 1993. The original aim was to examine the risk and benefit of using hormones during menopause in a prospective cohort design.
The original cohort
The original cohort includes all Danish female nurses over the age of 44, who were residents in Denmark in 1993 and were active or passive members of the Danish Nursing Council. Of the total of 23,170 nurses who received a questionnaire, 19,898 responded, equivalent to 86%.
In 1999, a new questionnaire survey was sent to the original cohort, and to all nurses who had reached the age of 44 years since 1993. This time, a total of 31,642 received a questionnaire, and 24,155, corresponding to 76%, answered. Of these, 15,322 participated in both the 1993 and 1999 study.
In 2009, the second follow-up survey was conducted. In 2009, questionnaires were sent to all women who had participated in the two previous surveys in 1993 and 1999. Questionnaires were sent to 12,955 women, of which 11,114 (86%) responded.
Mette Kildevæld is chairman of The Danish Nurse Cohort steering committee, you can read more about the cohort here