A Health Survey of Mothers Present at Their Infants Health Examination : Are the Subjects Representative of Those in Nationwide Surveys?

Abstract

An oral health survey of mothers who were present at dental examinations for their infants was conducted in four selected prefectures in Japan. The aim of this article was to assess the representativeness of the sample of this survey at different regional levels. The study areas were 33 municipalities selected using a stratified random sampling technique from each prefecture. From November 2005 to March 2006, we conducted oral examinations and questionnaire surveys at 138 sites. The oral examination methodology was the same as that for the national survey of dental diseases in 2005. The questionnaire survey consisted of subjective oral symptoms, knowledge and behavior regarding oral health, lifestyle habits, etc., and most questions were derived from existing national surveys. The number of subjects was 2,786 in oral examinations (response rate: 65%) and 3,301 for the questionnaire survey (response rate: 77%). The average age of the subjects was 31.4 years old. No significant difference was noted regarding the prevalence of dental caries and periodontal disease. The percentages of persons with untreated carious and missing teeth were lower in this survey. Regarding the questionnaire survey, most items did not show a significant difference from existing national surveys. However, the subjects in this survey followed a healthier lifestyle and undertook earlier dental visits. A few survey items were correlated with the response rate in each municipality. Although the survey items which showed significant differences from existing national surveys seemed to be affected by the characteristics of the selected prefectures and the subjects who were mothers of infants, the representativeness of the sample of this survey was considerably high. Therefore, this survey was considered to be an useful nationwide data source in Japan.