Investigation of Geographical Disparities: The Use of An Interpolation Method For Cancer Registry Data

J Okla State Med Assoc. 2023 Mar-Apr;116(2):62-71.

Abstract

The American Cancer Society estimated 1.9 million diagnosed cancer cases and 608,570 cancer deaths in 2021 in the US; for Oklahoma, they estimated 22,820 cases and 8,610 deaths. This project aimed to demonstrate a method to systematically describe cancer in an accurate and visually attractive, yet simple to make, interpolated map using ZIP Code level registry data, as it is the smallest area unit with high accuracy using inverse distance weighting. We describe a process of creating smoothed maps with an appropriate, well-described, simple, replicable method. These smoothed maps display low (cold) or high (hot) areas of incidence rates of: (a) all cancer combined, (b) colorectal cancer and lung cancer rates by gender, (c) female breast cancer, and (d) prostate cancer, by ZIP Codes for Oklahoma from 2013-2017. The methods we present in this paper provide an effective visualization to pinpoint low (cold) or high (hot) areas of cancer incidence.

Keywords: Cancer; GIS; Inverse Distance Weighting; Maps.