Cancer Hospitalizations in Rural-Urban Areas in Relation to Carcinogenic Discharges from Toxics Release Inventory Facilities
Cancer imposes a substantial financial burden on healthcare systems. Previous research has shown that lung cancer incidence and mortality rates in rural areas are significantly higher in relation to higher amounts of carcinogenic chemical discharges from Toxics Release Inventory (TRI) facilities. In contrast to mortality, a study of hospitalizations allows an approximation of population incidence rates, and indicates service needs that result from new case identification. Results of the study will help to inform environmental and healthcare policy decisions for cancer prevention and treatment in rural settings. These include potential revisions to environmental quality standards around TRI facilities, and policies to improve treatment for cancer in rural settings through targeted workforce needs or improvements in rural cancer treatment resources or best practices.
The study will test whether overall cancer hospitalization rates and cancer-specific hospitalization rates are related to releases of known carcinogens from TRI facilities nearby; will examine how the impacts of releases of known carcinogens on cancer hospitalization rates (overall and cancer-specific) vary across different urban-rural and level of rurality settings; and will investigate the association between the total inpatient dollar cost for cancer treatment and TRI carcinogens release, and assess how these associations differ in urban-rural and level of rurality settings. Hospitalization data will be obtained from the State Inpatient Databases (SID), a part of the Healthcare Cost and Utilization Project (HCUP). We will use the most recent complete year of available data, which includes 26 states for 2009. These states represent all regions of the country including states with large rural populations. Rural-urban classifications will be identified from zip code approximations of Rural Urban Commuting Area (RUCA) codes. Variables include primary cancer diagnoses, co-morbidities (e.g., diabetes), patient demographics (age, sex and race), payer, zip code income levels, and total charges. TRI data include amounts, types, and routes of discharge and will be obtained from the Environmental Protection Agency. Population figures by zip code will be obtained from Census data to calculate population hospitalization admission rates. Analyses will include hierarchical Poisson models where the dependent variable is the cancer-specific hospitalization rate and the independent variables are TRI release amounts to air and water and patient covariates. Dollar charges will be converted to cost estimates using cost-to-charge ratios to estimate public hospitalization costs associated with TRI carcinogen releases in rural and urban areas.