The Nord-Trøndelag Health Study 1995-97 (HUNT 2): Objectives, contents, methods and participation

The second Nord-Trondelag Health Study in 1995-97 (HUNT 2) was partly a follow-up study of HUNT 1, conducted in 1984-86. HUNT 2 comprised, however, a larger scientific program. The large amount of information collected from each participant, and the large number of participants in a wide age range covering an entire county population, make HUNT one of the largest health studies ever performed. This paper describes the survey covering persons aged 20 years and older. In total, 66.7% of men (n=30,860) and 75.5% of women (n=35,280) participated, the highest participation was in age group 60-69 and the lowest among the young and the elderly. Data collected from several questionnaires and with blood and urine samples and various clinical measurements, some of them in sub-samples of the study population, comprise a huge database for research. All data for each person are linked, and data are also linked to various health registries; all data handling being supervised by The Data Inspectorate and The Regional Ethical Committee. Procedures for data access are established, and more than 100 researchers are currently working on HUNT data. A large number of scientific papers in various disciplines are published, among them 15 doctoral theses (June 2003). The research potential of the HUNT biobank is still not fully exploited, but initiatives are taken. In line with other population based studies both in Norway and abroad, there was a decline in participation rate from HUNT 1 to HUNT 2 (16.9%). This has raised concern about the validity of future population based health studies. However, the good local and national network and the support from the population, make up a good platform also for future health studies in Nord-Trondelag.