Causes, Fundamental

PUBHLTH 405
Social Epidemiology of Infectious Disease
University of Michigan School of Public Health

Jon Zelner
[email protected]
epibayes.io

Goal for Today

Getting ready to read Infectious Fear

Agenda

• What is a fundamental cause and how is it different from a plain-old cause?

• How do we understand health (in)equity and why does it matter?

• How do these concepts relate to the problem of infectious disease transmission and illness progression?

Fundamental Causes

What is the fundamental cause approach?

• Mental model about the generation of health inequalities as a function of high-level risks like socioeconomic status (SES) and racism.

• Focuses on how upstream determinants put individuals at risk of risks.

• Important for understanding how health inequities cluster in populations and geographic locations.

• Prioritizes structural over individualistic explanations.

What is socioeconomic status?

A cluster of flexible resources that individuals can marshal to their advantage:

• Income & Wealth

• Education & access to information

• Class privilege (e.g. the “hidden curriculum”) navigating social and medical settings

• Social relationships that may provide “insider” access

What makes a cause fundamental?

• Impacts multiple more-proximal risks for disease at the same time.

• Consequently, also likely to drive risk across multiple health outcomes.

• The cause itself is related to the ability to access resources that allow one to avoid an illness or mitigate its impacts.

• Critically: Association persists even when proximal mechanisms are addressed, because they are replaced by new ones.

“The purpose of a system is what it does.”

It’s easy to mistake the POSIWID view of the world for a slightly tiresome kind of cynicism. To say that the purpose of the system is what it does isn’t to make any statement about the intentions of the people working for it. The danger of confusing the properties of the system with those of its members is one of the most important reasons for not opening up a black box. Unfortunately, it’s a very common confusion; very few people are able to take a step back, view their own organisation as if from outside, and realise that they are structurally producing results which are exactly the opposite of what they had intended. (Davies 2024, 53)

This quote is attributed to Stafford Beer, an influential systems theorist.

Why is racism a fundamental cause on top of SES?

Why can’t socioeconomic status explain all race/ethnic health inequities?

Racism has many impacts on health that go beyond and modify those of SES

• Differential quality of medical treatment.

• Differential access to health-promoting environments.

• Employment and housing discrimination.

• Emotional and physical stress resulting from prolonged exposure to discrimination.

What are some other potential fundamental causes?

• Residential segregation

• Social stigma

• Racial capitalism (Laster Pirtle 2020)

• What else?

Residential segregation may compound impacts of SES and racism.

What intervening mechanisms are we talking about when we talk about segregation as a fundamental cause? (map from (ESRI 2022))

What do we talk about when we talk about health (in)equity?

• Open up this document

• Going to spend ~15m on your group’s question.

• We will then split into groups with 2-3 “experts” from each original group and review, discuss, and edit the answers of the original group.

• After everyone has done all of these, we’ll come back and discuss these in the context of the readings.

Some more implications of the fundamental cause approach

FCT explains how innovation acts as an engine 🛫 of health inequality

• When new tools and technologies are available for prevention and treatment, they are first available to the most-privileged.

• This introduces or increases inequity in outcomes at first.

• Over time, the tool becomes available to more people and inequity decreases.

• Over time, the innovation saturates the population and inequality stabilizes or disappears.

This leads to a relatively predictable life-cycle of inequity

Example of how inequity rises and falls as an innovation diffuses through the population from (Zapata-Moya, Willems, and Bracke 2019)

We can see the generation of inequality during the first phases of covid

Changes in SARS-CoV-2 mortality by SES of U.S. counties. High SES counties are represented by the short-dashes, all others by long-dash and solid line (from (Clouston, Natale, and Link 2021))

What interventions or policies might explain this pattern?

How can we apply FCT to infectious disease specifically?

Socio-structural inequities drive unequal outcomes across the entire life-cycle of infection

Flow diagram from Zelner et al. (2022)

What is the distinction between inequity in exposure versus susceptibility?

Mechanisms leading to differential exposure to infection from (Noppert, Hegde, and Kubale 2022)

What is the distinction between inequity in exposure versus susceptibility?

Mechanisms leading to differential vulnerability to infection from (Noppert, Hegde, and Kubale 2022)

Link & Phelan identified structural determinants of infection inequity in their original work

An example of how fundamental causes may be reflected in foodborne infection (Link and Phelan 1995)

Next Time

Racial inequality in Tuberculosis infection and mortality in the 20th Century

• Read Chs. 1 & 2 of Infectious fear

• First chapter lays out the big picture of TB disparities by race in the early-mid 20th century.

• Second chapter gets into more of the race science that was used to explain TB disparities and suggest that African-Americans were somehow more biologically and morally vulnerable to disease.

References

Clouston, Sean A. P., Ginny Natale, and Bruce G. Link. 2021. “Socioeconomic Inequalities in the Spread of Coronavirus-19 in the United States: A Examination of the Emergence of Social Inequalities.” Social Science & Medicine 268 (January): 113554. https://doi.org/10.1016/j.socscimed.2020.113554.

Davies, Dan. 2024. The Unaccountability Machine: Why Big Systems Make Terrible Decisions - and How The World Lost Its Mind. Profile Books.

ESRI. 2022. “Race and Ethnicity in the US by Dot Density (Census 2020) - Overview.” https://www.arcgis.com/home/item.html?id=30d2e10d4d694b3eb4dc4d2e58dbb5a5.

Laster Pirtle, Whitney N. 2020. “Racial Capitalism: A Fundamental Cause of Novel Coronavirus (COVID-19) Pandemic Inequities in the United States.” Health Education & Behavior, April, 1090198120922942. https://doi.org/10.1177/1090198120922942.

Link, Bruce G., and Jo Phelan. 1995. “Social Conditions As Fundamental Causes of Disease.” Journal of Health and Social Behavior 35: 80. https://doi.org/10.2307/2626958.

Noppert, Grace A, Sonia T Hegde, and John T Kubale. 2022. “Exposure, Susceptibility, and Recovery: A Framework for Examining the Intersection of the Social and Physical Environment and Infectious Disease Risk.” American Journal of Epidemiology, October, kwac186. https://doi.org/10.1093/aje/kwac186.

Zapata-Moya, Ángel R., Barbara Willems, and Piet Bracke. 2019. “The (Re)production of Health Inequalities Through the Process of Disseminating Preventive Innovations: The Dynamic Influence of Socioeconomic Status.” Health Sociology Review 28 (2): 177–93. https://doi.org/10.1080/14461242.2019.1601027.

Zelner, Jon, Nina B. Masters, Ramya Naraharisetti, Sanyu A. Mojola, Merlin Chowkwanyun, and Ryan Malosh. 2022. “There Are No Equal Opportunity Infectors: Epidemiological Modelers Must Rethink Our Approach to Inequality in Infection Risk.” PLOS Computational Biology 18 (2): e1009795. https://doi.org/10.1371/journal.pcbi.1009795.