Trends In Socioeconomic Inequalities In Primary Caries In China

This study aimed to evaluate the socioeconomic inequality of primary caries in children aged 5 years in China in 2005 and 2015 and analyze changes during ten years. Data on 5-year-old children from the 3rd and 4th National Oral Health Survey (NOHS) were extracted. After cleaning and weighing the data, using caregivers' education as a socioeconomic indicator, slope index of inequality (SII) and relative index of inequality (RII) were used to measure the inequality of primary caries in 2005 and in 2015 qualitatively and quantitatively. In 2005, the absolute and relative inequality of dmft were higher in urban children than rural children. In 2015, the urban-rural difference in inequality disappeared. During this decade, socioeconomic inequalities of dmft in urban children decreased in absolute scale and relative scale (SII: 2.28 to 0.96, RII: 1.92 to 1.25, P-trend<0.05). In 2015, socioeconomic inequality in dmft existed in rural children (SII:0.61, RII: 1.14). The inequality changes were not statistically significant (P-trend>0.05). Though the inequality of dmft narrowed among 5-year-old children in urban areas, there were persisting parental education-related inequalities in dmft. Considering the appearance of inequality in dmft in rural children in 2015, the policy-makers should focus on the oral health among children with less-educated parents and give priority to optimizing distribution of education resources and reducing parental education-related inequalities in preschool children.