Exploring Associations between Incarceration, Inflammation, and Chronic Health Diagnoses in Older Adults: A Mediation Analysis

Background and Purpose: The United States is a global leader in the number of incarcerated persons around the globe. People who experience incarceration are known to have worse health outcomes for chronic health conditions, potentially through an increase in inflammation. However, no studies have yet to test inflammation as an explanatory pathway between incarceration and chronic health conditions.

Methods: Data are from the Health and Retirement Survey (HRS). We used a two-phase modeling strategy to test the associations between incarceration, inflammation, and chronic health conditions. First, we used a regression-based mediation analysis to test if the association between incarceration and the number of chronic health conditions was mediated by inflammation. Incarceration history was measured categorically via participant self-report of spending at least three consecutive days in jail or prison. Inflammation was indexed via C-reactive protein (CRP). Chronic health diagnoses were measured as an index of six diagnoses: heart disease, hypertension, lung disease, diabetes cancer, stroke. Second, we conducted six additional regression-based mediation analyses to understand how inflammation may mediate the association between incarceration and the six individual chronic health conditions. All analyses controlled for: smoking status, alcoholic drinks per day, physical activity, wealth, Medicaid status, age, sex, and racial/ethnic identity. All analyses accounted for the complex survey design of the HRS data set. Mediation analysis was conducted via bootstrapping.

Results: The sample was 84.86 % White, 55.99% female, and had a mean age 68.91 years. Participants had a mean of 1.31 chronic health diagnoses. Incarceration had a significant direct effect on the number of chronic conditions diagnosed (b=0.26, SE=0.08, p<0.01). Incarceration was also associated with an increase in CRP (b=0.14, SE=0.06, p<0.05), and incarceration (b=0.17, SE=0.07, p<0.05) and CRP (b=0.16, SE=0.01, p<0.001) were both associated with an increase in chronic conditions diagnosed. CRP significantly mediated the association, mediating 13.48% [95% CI: 0.03-0.30] of the effect of incarceration on the number of chronic conditions diagnosed. Among individual diagnoses, incarceration had a direct effect on the odds of being diagnosed with cancer (b=0.65, SE=0.18, p<0.001), but no other diagnosis; however, CRP was positively associated with each individual diagnosis. CRP significantly mediated the association between incarceration and being diagnosed with cancer, mediating 2.60% [95% CI: 0.004-0.06]. of the effect.

Conclusion and Implications: Incarceration relates to greater inflammation in older adults, helping to explain the risk for multiple morbidities and cancer specifically. Despite the lack of direct effects between incarceration and the diagnosis of several chronic conditions, incarceration was linked to elevated inflammation, a common risk factor for the development of these disorders. Thus, results may point to a gap in access to medical care for people who experience incarceration. Advocating for improved health care while incarcerated and material conditions (such as improved cleanliness and healthier food options) while incarcerated may be important steps in reducing inflammation for those who experience incarceration. Further, social workers embedded in re-entry programs should focus ensuring individuals who have experienced incarceration have access to medical providers who can then monitor inflammation and prescribe anti-inflammatory therapies.