National Study of Adult Oral Health 2017-18: participation and representativeness.

The National Study of Adult Oral Health (NSAOH) 2017-18 collected information from a sample of the Australian population aged 15 years and over. The Study comprised an interview questionnaire, completed by telephone or online, and an oral epidemiological examination among dentate participants. Participation in the Study was voluntary and therefore relied on the goodwill of selected participants. This paper provides a summary of participation rates for the Interview and Examination phases of the study. The potential for biased population estimates due to variation in participation rates is explored. The weighting procedure implemented to ensure the sample is representative of the target population is described and a comparison of the estimated population distributions derived from the weighted sample and the actual population distributions is provided for a range of socioeconomic characteristics. In summary, it can be concluded that estimates derived from the weighted Interview and Examination samples are valid estimates of the Australian population aged 15 years and over.