The Doetinchem Cohort Study is a prospective longitudinal study on lifestyle and other determinants of health and disease as they develop over the life course and during ageing, with individual data covering 25 years. At present, the participants of the study have been followed for almost 30 years.

It started in 1987 as a monitoring study on cardiovascular disease risk factors, with an age-sex stratified sample from the inhabitants of Doetinchem, (20-59 years), a provincial town in The Netherlands.  Of those invited, 12.404 (62%) participated in the baseline examination.

Two-third of those assessed at baseline (n=7768) were invited for a first follow-up measurement in 1993-1997 (round 2: n=6117), and every five years since. Currently, round 7 is ongoing, covering the period 2018-2022. The average response rate overall rounds is 78%.

A broad range of factors, including lifestyle, biological, health (physical and psycho-social), wellbeing, presence of disease, and care factors are assessed. Some unique characteristics of the study are:  a broad age range is covered; biological materials (including blood) are collected at every measurement round and stored (biobank); extensive lung function measurements and cognition tests from a young age onwards.

The Doetinchem Cohort Study is carried out by the National Institute for Public Health and the Environment in collaboration with the Municipal Health Service in Doetinchem and supported by the Dutch Ministry of Health, Welfare and Sport.