Data from the National Children's Database

All Danish parents are offered preventive health and functional examinations of their children. In the first year of the child's life, the examinations are carried out by health care providers in their own homes. When the child is of compulsory school age, most examinations, including statutory in-service and out-of-school examinations, are carried out at school by health care providers or municipally employed doctors.

Data from these studies are collected in the National Children's Database. This allows for nationwide inventories of duration of breastfeeding, exposure to tobacco smoke at home, and prevalence of obesity.