The problem of participation in the Dutch National Dental Survey

In 1986 a nationwide dental survey was carried out in the Netherlands. The aims of the study were to assess the prevalence of oral diseases, need and demand for dental care and oral selfcare in the Dutch population aged 15–74 yr. This paper describes the general sampling and analysis procedures to detect selectivity in the participation. Irregular dental attenders seemed to be underrepresented in the final sample. Poststratification was used to overcome this problem of selectivity