The need to study rural cancer outcome disparities at the local level: a retrospective cohort study in Kansas and Missouri

Abstract

Background Rural residence is commonly thought to be a risk factor for poor cancer outcomes. However, a number of studies have reported seemingly conflicting information regarding cancer outcome disparities with respect to rural residence, with some suggesting that the disparity is not present and others providing inconsistent evidence that either urban or rural residence is associated with poorer outcomes. We suggest a simple explanation for these seeming contradictions: namely that rural cancer outcome disparities are related to factors that occur differentially at a local level, such as environmental exposures, lack of access to care or screening, and socioeconomic factors, which differ by type of cancer. Methods We conducted a retrospective cohort study examining ten cancers treated at the University of Kansas Medical Center from 2011 to 2018, with individuals from either rural or urban residences. We defined urban residences as those in a county with a U.S. Department of Agriculture Urban Influence Code (UIC) of 1 or 2, with all other residences defines a rural. Inverse probability of treatment weighting was used to create a pseudo-sample balanced for covariates deemed likely to affect the outcomes modeled with cumulative link and weighted Cox-proportional hazards models. Results We found that rural residence is not a simple risk factor but rather appears to play a complex role in cancer outcome disparities. Specifically, rural residence is associated with higher stage at diagnosis and increased survival hazards for colon cancer but decreased risk for lung cancer compared to urban residence. Conclusion Many cancers are affected by unique social and environmental factors that may vary between rural and urban residents, such as access to care, diet, and lifestyle. Our results show that rurality can increase or decrease risk, depending on cancer site, which suggests the need to consider the factors connected to rurality that influence this complex pattern. Thus, we argue that such disparities must be studied at the local level to identify and design appropriate interventions to improve cancer outcomes.

Urban–Rural Disparities in the Lung Cancer Surgical Treatment Pathway: The Paradox of a Rich, Small Region

“…It is therefore important to study the association between cancer pathways disparities and rurality at the local level. As demonstrated by other authors, rurality can increase or decrease cancer-related risks and outcomes, suggesting a complex pattern ( 8 ).…”

“…Several studies have recognized among rural residents higher rates of cancer-risk behaviors such as cigarette smoking, poorer diet, alcohol abuse, physical inactivity, and obesity ( 4 – 6 ). An additional explanatory factor in broad countries such as the United States and Australia is that a considerable percentage of uninsured or underinsured patients come from rural regions ( 1 , 4 , 6 – 8 ). Furthermore, rural inhabitants often present lower incomes and lower educational levels than their urban counterparts ( 1 , 2 , 6 , 7 ).…”

“…However, the above-mentioned data are mostly extracted by studies performed in extremely wide and non-homogeneous countries, in terms of both population and socio-economical levels, such as the United States and Australia ( 1 – 3 ). Therefore, it seems to be interesting to study and verify this phenomenon at a local level in order not to generalize the results ( 8 , 9 ), especially with a view to introducing a screening program ( 10 ). Switzerland is a tiny state with 8,670,000 inhabitants, with one of the highest per capita incomes worldwide.…”

Rural–Urban Disparities in Health Access Factors Over Time: Implications for Cancer Prevention and Health Equity in the Midwest

“…27 , 28 To better understand rural–urban disparities in cancer outcomes, a recent study highlighted the importance of considering cancer-related environmental and lifestyle factors at the local level. 29 …”

Geographic differences in community oncology provider and practice location characteristics in the central United States

“…First, we limited our study to 13 states in the central United States, which has a particular sociogeographic context, so it should not be construed to be representative of the entire United States, especially since regional variations have been noted. 57 In addition, we identified oncologists and practice locations based on Medicare billing. While considered to be accurate, as it is used for payment, we would not expect it to identify oncologists providing care exclusively to children or other non-Medicare billing oncologists.…”