Using cartograms to illustrate disparities in oral health in Kentucky

Objectives

Cartograms, or density-equalizing maps, were used to visually depict an oral health indicator and its association to demographic and socioeconomic variables in Kentucky.

Methods

We created cartograms (wherein geographic areas such as counties or states are reshaped and resized in proportion to a variable) using ArcGIS 9.1 that visualize indicators including population, education, dental manpower, and income based on county data in Kentucky. Counties were transformed to adjust for the indicators of interest using the Gastner and Newman diffusion algorithm. A shaded depiction (chloropleth) of an oral health indicator (missing 6 or more teeth) was applied to each cartogram.

Results

The maps show the disparities that exist in Kentucky with respect to oral health and the association with oral health and the examined indicators. The disparities in oral health in Kentucky are exacerbated by the striking differences in income and the dental workforce between counties.

Conclusions

The cartograms presented provide a different visual representation of disparities in oral health outcomes and access. These cartograms can be utilized as tools for policy makers to make more informed decisions when allocating funds for oral health.