The Northern Sweden Health and Disease Study, NSHDS, is a biobank with questionnaire data and blood samples from several population-based cohort studies in northern Sweden. The largest cohort is the Västerbotten Intervention Programme, VIP, which started in 1984. The program includes an invitation of all inhabitants in the county of Västerbotten to their regular health care center the year they turn 40, 50 or 60 years of age. For a few years, also 30-years old subjects were invited.