Using GIS to analyse dental practice distribution in Indiana, USA

Dentistry across the globe faces significant workforce issues with mal-distribution at most levels of analysis being a substantial issue. This study was the first to apply high resolution Geographic Information Systems (GIS) tools to map every private dental practice in the State of Indiana against a backdrop of population demographics. The hypothesis tested in the study is that there is an even density distribution of dental practices across Indiana.

Adult population data were obtained from the United States Census of Population and divided by census tracts. The physical address for each dental practice in Indiana was collated from a comprehensive web-based search and the two datasets were integrated using GIS tools.

The whole adult population of Indiana (5 million) was distributed across 1,511 census tracts. Across these tracts a total of 2,096 separate private general dental practices were distributed. There were a total of 679 tracts (45%) without a dental practice while 2.5% of tracts had 8 or more practices.

The practice to population ratio (1:2,384) for the whole State was not significantly different for those living within 50km (31 miles) or 25km (15 miles) of the seven major city centers, and mean personal income (by residency location) did not appear to significantly influence practice location.