Urban-rural differences in the prevalence of having a family dentist and their association with income inequality among Japanese individuals: a cross-sectional study.

backgroundFew reported studies evaluate the status of those who have a family dentist (FD) by regional differences and the socioeconomic factors associated with this status. This study aimed to assess the prevalence of having an FD among Japanese individuals across three samples of municipality type: urban, intermediate, and rural areas, and determine the factors associated with having an FD.

methodsThis was a cross-sectional study involving a web-based survey. In total, 2,429 participants (comprising men and women aged 20-69 years) were randomly selected from among the registrants of a web research company: 811 urban residents, 812 intermediate residents, and 806 rural residents. In each area, we categorized the participants into those who had an FD (FD group) and those who did not (non-FD group). A multivariate modified Poisson regression analysis was used to determine the factors associated with the FD group as compared to the non-FD group.

resultsThe proportion of the FD group was lowest in rural areas (42.3%), followed by intermediate (48.6%) and urban areas (49.7%). The regression analysis revealed a statistically significant tendency between associated factors in the two groups; that is, the higher the household income, the more likely that the family belonged to the FD group (prevalence ratio (95%CI), JPY 4-6 million: 1.43 (1.00-2.03), JPY ≥ 8 million: 1.72 (1.21-2.44)).

conclusionsRural areas have the lowest proportion of people with an FD among the three areas, and income inequality is associated with having an FD. Thus, when planning policies to encourage individuals to have an FD to manage their oral health, it is necessary to consider regional differences.