UCSF

Although incidence and mortality rates of colorectal cancer (CRC) in the United States (US) have declined in recent years, all populations have not benefited equally of improvements in screening and treatment. Racial and ethnic minoritized groups, low-income people and uninsured persons face the highest burden of this disease. Recent developments in cancer research have highlighted the need for evaluating neighborhood and social level factors in addition to individual characteristics, as they capture information on access to resources that are key elements of cancer risk. The overarching goal of this dissertation was to evaluate the relationship between the social environment and CRC screening and stage at diagnosis in the US, and to determine the role of public health policy in reducing racial and ethnic disparities.Residential segregation has shaped the history of the US, providing resources and better opportunities to people residing in some neighborhoods, while disinvestment have taken place in other areas (mostly inhabited by Black and other racial and ethnic minoritized groups). On the other hand, with the Medicaid expansion provision of the Patient Protection and Affordable Care Act (ACA), access to health insurance has been facilitated to underserved people. Yet, many states have decided not adopting it. This dissertation used national datasets representative of all areas in the US and a novel measure of residential segregation to capture the social environment of individuals and its association with CRC outcomes (Chapters 1 and 2). This dissertation also evaluated the effect of Medicaid expansion in reducing health inequities after the implementation of the ACA (Chapter 3).