Women's lifestyle and health (WLH)

Oral contraceptives, use of hormone replacement therapy, dietary habits and other lifestyle factors affect the risk for cancer, cardiovascular diseases and other chronic diseases in young women. The overall aim of Women's lifestyle and health cohort is to examine lifestyle factors and health outcomes such as cancer, cardiovascular diseases and some chronic diseases. Starting in 1991, a comprehensive questionnaire was mailed to 96,000 Swedish women aged 29-49 years. Approximately 50,000 completed questionnaires were returned providing detailed information on a wide range of lifestyle factors with a focus on oral contraceptive use, diet, UV light exposure, and reproductive factors. This study is strictly coordinated with a similar study among 60,000 young women in Norway; apart from the dietary component, the questionnaires are identical and joint analyses have been conducted. In 2003, a second questionnaire was sent to all women to update information on lifestyle, and hormonal factors as well as to assess mental health. Currently analysis is ongoing for several lifestyle factors and cancers of the breast, ovarium, endometrial, colorectal, skin, skin melanoma, lymphomas, as well as cardiovascular outcomes (myocardial infarction, haemorragic and ischaemic stroke), psychiatric diseases, sleeping disorders and overall mortality. Several analyses have been performed during the last years on different exposures, such as oral contraceptives, BMI, changes in body size and shape, UV radiation exposure, alcohol consumption, smoking, and risk of different cancer sites and overall mortality. The baseline questionnaire was mailed to 96,000 Swedish women aged 29-49 years, in 1991. The questionnaire was answered by 49,259 women. Participants from the baseline collection were followed up in 2003.