The table shows participation numbers for respondents to questionnaire 1. It is possible to define different definitions of participations, depending on the focus of a study. That is one of the reasons for differeing participation numbers in different publications. A second reason is the possibility to withdraw participation at any given moment in time, also long after datagathering took place. A third reason is quality assurance work by HUNT databank, resulting in correction of some numbers.*
Table showing participants with samples in HUNT2 and HUNT3
Krokstad S, Langhammer A, Hveem K, Holmen TL, Midthjell K, Stene TR, Bratberg G, Heggland J, Holmen
Cohort Profile: the HUNT Study, Norway.
J.Int J Epidemiol. 2013 Aug;42(4):968-77. doi: 10.1093/ije/dys095. Epub 2012 Aug 9.
* In some earlier publications, participation in HUNT1 and HUNT2 was defined as response on questionnaire 1 PLUS participation in at least one of the physical examinations on height, weight, blood pressure or blood glucose. Older HUNT publications will therefore present different participation numbers. (The numbers presented here are from May, 2012.)