The national monitor with main results of the NBS is carried out annually by TNO at the request of the RIVM-CvB (Rijksinstituut voor Volksgezondheid en Milieu-Centrum voor Bevolkingsonderzoek). The monitor enables insight into the functioning of all aspects of the NBS as well as insight into a possible need for extra measures to allow for an improvement in functioning of the screening (onderzoek) program.