A multi-variable analysis of four factors affecting caries levels among five-year-old children; deprivation, ethnicity, exposure to fluoridated water and geographic region

Objective: To assess the role of factors posited to affect population caries levels across England. Basic research design: Multivariable regression analysis assessing four potential determinants of caries severity and prevalence: deprivation, exposure to fluoridated water, ethnicity and geographic region Participants: Random sample of 121,875 five-year-old children in England in the 2014/15 academic year. Main outcome measures: Decayed, missing and filled teeth, with decay measured at the dentinal level, (d ₃ mft), presented as prevalence (dmft>0) and extent of decay among children who have any (d ₃ mft if d ₃ mft>0). Independent variables: Parental reported ethnicity from school records, index of multiple deprivation (IMD) scores, region and exposure to water fluoridation calculated utilising home postcodes. Results: The data support wider literature displaying associations between caries and deprivation across a social gradient. The important, new findings are deprivation, some ethnic groups and lack of exposure to water fluoridation are all associated with increased prevalence and severity of caries when considered together and independently. New evidence supports the impact of water fluoridation on health inequalities in that the greatest impact of exposure to fluoridated water was seen in the most deprived children and those from an Asian / Asian British ethnic group. Conclusions: Five-year-old children who were from the most deprived areas, not exposed to fluoridated water, of an Eastern European ethnic group and living in the North West demonstrated the highest prevalence and severity of caries in the survey under scrutiny. This is of public health importance, providing evidence for population groups to target with health improvement activities.