Disparities in colorectal cancer time-to-treatment and survival time associated with racial and economic residential segregation surrounding the diagnostic hospital, Georgia 2010–2015

1

Introduction

Colorectal cancer (CRC) is the fourth most common cancer in the United States, represents approximately 8 % of cancer diagnosis and deaths, and has a 5-year survival rate of approximately 64 % [1] . An estimated 151,030 cases will be diagnosed in 2022 [1] , almost universally through colonoscopies, which are recommended for all adults as they age [2] . This diagnosis and subsequent treatment are critical to long-term survival and are aided by doctor-patient relationships [34] , available diagnostic facilities [5] , and patient willingness and ability to seek care [6] . Black patients have been found to have poorer survival rates even after controlling for many of these variables [78] . There is considerable literature about the importance of early screening, but less is known about the impact of features of diagnosing hospitals on overall patient outcomes.

Pre- and post-cancer care outcomes for CRC are particularly reliant on timely and appropriate treatments, which in turn, are predicted by health providers’ location and available resources [910] . In the context of the timely cancer treatment, residential segregation of a location has become an important topic of inquiry for understanding health-related behavior in context of the social and structural environment [11] . Residential segregation can be described in terms of the population characteristics, such as race or income, and is a characteristic of the immediate region and its surrounding regions [12] . It may occur across racial lines, may more closely follow economic linkages, or some combination of the two [13] . Rates of residential segregation may differ dramatically from the overall level of affluence or racial composition of a region [14] . Scholarship has found that residential segregation metrics explain some elements of the Black‐White disparity in CRC screening and diagnosis timing [15] , though it is not clear that residential segregation similarly influences treatment or survival.

Prior work has primarily focused on segregation associated with the residence of the individual, which is an important perspective on how experiences at home may influence health. We propose an important consideration of the residential segregation of the hospital or facility where an individual is diagnosed, as a measure of social geography associated with health care. This research provides an understanding of how hospital location may influence health care and evaluating this segregation level provides a potential intervening point of the hospital to improve care.

We focus on the state of Georgia, a study area with a history of scholarship surrounding CRC screening and treatment, with many efforts focused on limiting disparities towards the low-income Black population [16] as well as rural patients [17] . While Black patients were less likely to have a late-stage diagnosis, they have been found to be less likely to undergo surgery and at higher risk of death [18] . While rural patients have been found to have poorer outcomes regardless of race [19] , the effects driving racial variance within cities has been variously attributed to suburban or urban status [20] , with calls for additional scholarship to consider other mechanisms by which these disparities might be framed and analyzed [1821] .

The objective of this paper is to unfold this complexity in the following manner: evaluate whether social geographic factors of the hospital in which an individual is diagnosed is associated with time-to-treatment and survival time in colorectal cancer patients, specifically exploring whether a relationship with racial or economic disparity exists; and, to explore the patterns in the availabilities of multiple cancer-diagnostic and treatment technologies along these social geographic factors. Our research will assess whether the residential segregation of socioeconomic elements surrounding healthcare entities potentially important explanatory factor for cancer outcomes [22] .