Cohort profile update: HUNT4 70+

The Trøndelag Health Study (HUNT) in Norway has surveyed lifestyle and health in more than 50% of the local adult population every decade since 1984-86. HUNT4 70+ is a sub-cohort of persons aged at least 70 years at the 4 ^th survey of the HUNT Study, established to provide data for ageing research. This population-based sample consists of 9956 individuals from the original HUNT catchment area, included between August 2017 - February 2019. Of these, 9589 have been included in one or several of the former surveys. In addition, an urban sample of 1743 persons was included in Trondheim city in the period October 2018 – June 2019. HUNT4 70+ covers comprehensive aspects of ageing health, including clinical examinations, performance-based tests of physical and cognitive function, questionnaires, and biological samples. High participation rates among the old and frail were obtained by examination in private homes and nursing homes when needed (15% of the participants). The data can be linked to all national registers in Norway, such as cause of death, prescription, health care utilization, and diagnosis registries.