June 2020

Objective: To describe the shape of the relationship between area deprivation and dental attendance (DA) in children aged 5 years and under in England and the modifying effect of caries prevalence, ethnicity, family profile and dentist-to-population ratio. Basic research design: DA rates were calculated at lower-tier local authority level (LA, n=326) using NHS data for the year to March 2017. LA deprivation was determined by Index of Multiple Deprivation 2015. Caries prevalence was retrieved from the 2016/17 National Dental Epidemiology Programme; ethnicity and family profile from Census 2011 and dentist-to-population ratio from NHS statistics. Fractional polynomial (FP) models explored the shape of the relationship. Multivariable regression models were adjusted for covariates. The effect of moderators was estimated by adjusted marginal effects. Clinical setting: English Lower-tier LAs. Main outcome measure: Shape of the relationship between DA and deprivation and its moderators. Results: Best-fitting second-order FP model (p=0.582) did not provide a better fit for the relationship than the linear model. Therefore, the linear model was selected for final analysis. Deprivation was associated with decreased DA rates (Coefficient=-0.39, 95%CI=-0.53,-0.24; p=<0.001); while White ethnicity (Coefficient=0.35, 95%CI=0.29, 0.41; p=<0.001), single parenthood (Coefficient  =  2.21, 95%CI=0.91,3.51; p=0.001) and caries prevalence (Coefficient  =0.34, 95%CI=0.25,0.44; p=<0.001) with increased rates. These moderated the relationship. Conclusions: We hypothesised that the shape of the relationship between deprivation and DA could be curvilinear with higher rates in the extreme ends of deprivation. However, the analysis showed a linear association, moderated by the effect of ethnicity, single parenthood and disease level. Keywords: socioeconomic factors, dental caries, dentistry, dental health services, dental attendance