Title : Geospatial mapping and assessment of risk factors for colorectal cancer at small area
Abstract:
Objectives: Examining spatial distribution of colorectal cancer (CRC) incidence or mortality is helpful for developing cancer control and prevention programs, or for generating hypotheses. Such an investigation involves describing the spatial variation of risk factors for colorectal cancer and identifying hotspots. The aim of this study is to identify small area level risk factors that may be associated with the incidence of colorectal cancer and to map hotspots for colorectal cancer.
Methods: Colorectal cancer cases in small areas were recorded in 2018 and measurements on risk factors were also obtained. We used Bayesian spatial models for relative incidence rates and produced posterior predictive that indicates excess risk (hotspots) for colorectal cancer.
Results: The small area level unadjusted incidence rates ranged from .462 to 3.142. After fitting a Bayesian spatial model to the data, the results show that a decreasing risk of colorectal cancer is strongly associated with an increasing median income, higher percentage of Black population, and higher percentage of sedentary life at small area level. Using exceedance probability, it is also observed that there are clustering and hotspots of high colorectal cancer incidence rates in some regions.
Conclusion: Among few small area level variables that significantly explained the spatial variation of colorectal cancer, income disparity may need more attention for resource allocation and developing preventive intervention in high-risk areas for colorectal cancer.
