Contribution of County Characteristics to Disparities in Rural Mortality After Cancer Diagnosis

Abstract

IntroductionRural disparities in cancer outcomes have been widely evaluated, but limited evidence is available to describe what characteristics of rural environments contribute to the increased risk of poor outcomes. Therefore, this manuscript sought to assess the mediating effects of county characteristics on the relationship between urban/rural status and mortality among patients with cancer, characterize county profiles, and determine at-risk county profiles alongside rural settings. MethodsPatients diagnosed with cancer between 2000 and 2016 were assessed using Surveillance, Epidemiology and End Results (SEER) data linked to the 2010 Rural-Urban Commuting Codes and 2010 County Health Rankings (CHR). There were 757,655 patients representing 596 counties (of 3143 in the US) and 12 states. Mediation analyses, conducted in 2023, estimated the direct contribution of rurality to five-year all-cause survival and the contribution of the rural effect indirectly through CHR domains. Latent class analysis and survival models identified county groupings and estimated the hazard of mortality associated with class membership. ResultsRankings for premature death, clinical care, and physical environment resulted in rural patients having 17.9%-20.2% less survival time compared to urban patients. Of this, 4.1%-12.6% of the total excess risk was mediated by these characteristics. Patients living in rural and high-risk county classes saw higher all-cause mortality than those in urban-lower risk counties (HR, 1.04, 95%CI 1.01-1.08 and 1.07, 95%CI, 1.03-1.11). ConclusionsCounties with poorer health rankings had increased mortality risks regardless of rurality; however, the poor rankings, notably health behaviors and social & economic factors, elevated the risk for rural counties.