The political polarization of health outcomes in the USA

Key Points:

• A longitudinal study using the Add Health survey tracked a US cohort born 1974–1983, showing that by 2016–2018, conservatives exhibited significantly worse health biomarkers (BMI, cholesterol, HbA1c, blood pressure, C-reactive protein) than liberals, a gap not present in 2008–2009.
• The health disparity grew due to both individuals becoming more conservative as their health declined and conservatives experiencing worsening health; about half of this gap is explained by socioeconomic, behavioral, and contextual factors, while the rest may relate to unmeasured ideological differences affecting health behaviors.
• Mortality data from 2001 to 2022 indicate that conservatives had higher death rates than liberals starting in the late 2010s, particularly from internal causes like heart disease and cancer, with the mortality gap becoming statistically significant after 2020, partially but not fully attributable to COVID-19.
• A 2024 survey found that conservatives and Republicans are less likely to trust, visit, and follow advice from primary care providers, including among those with chronic illnesses, suggesting political beliefs influence healthcare engagement beyond COVID-19-related issues.
• The persistent health and mortality gap between liberals and conservatives is only partly explained by demographics and geography; declining trust and adherence to medical advice among conservatives may be a key factor driving worse health outcomes in this group.