Stress-Testing Epidemiological Theory with Plausible Reasoning: An Investigation of Colorectal Cancer Inequalities in Texas

Keywords: epistemology, methodology, cancer, social inequality, health geography
Abstract Type: Paper Abstract

Abstract

Plausible reasoning (PR), as developed by the likes of George Polya and Harold Jeffreys, is an under-explored approach to research methodology and the philosophy of science. In this presentation, I will discuss how PR may contribute to ongoing debates over causality and causal inference in geography and epidemiology, especially for questions of social causality. I argue that PR complements realist philosophies of science, and may be understood, in part, as providing a logical framework within which debates over weight of evidence unfold. This offers an expansive methodology that contrasts with the highly circumscribed "causal inference" methods often employed in quantitative health research today.

Here I employ PR and realist concepts of causality to evaluate proposed explanations for racial inequalities in the colorectal cancer (CRC) burden. Drawing on the `neighborhood effects' literature, some epidemiologists hypothesize that residential segregation is the fundamental cause of racial cancer disparities. Through disease mapping and other analyses of CRC incidence data, I show that segregated areas in Dallas and Houston have persistently experienced very high CRC incidence rates. However, I argue that ongoing geographical transformations in Texas reveal segregation per se to be an inadequate way to conceptualize the causes of CRC inequalities, which have expanded geographically and polarized along class lines. I suggest that health geography and epidemiology stand to benefit from closer engagement with the critical human geography literature and its relational conceptualizations of class, race, and social space.