Health Insurance and Mortality in US Adults: A Cautionary Tale

A 2009 observational study reported that private insurance status is associated with decreased mortality risk compared to no insurance. Employing the same statistical model but with more recent data, we observe a weaker and statistically insignificant relationship. However, Medicaid coverage is associated with increased mortality risk; the adjusted hazard ratio for Medicaid compared to no insurance is 1.32 (95% CI = 1.01, 1.72). These findings bolster concerns about using observational studies to understand the health consequences of insurance.