To clarify the relationship between having health insurance and the diagnosis and management of diabetes, high blood pressure, and high cholesterol, Daniel Hogan of the World Health Organization, Joshua Salomon at the Harvard T. H. Chan School of Public Health, and coauthors analyzed 1999-2012 data from the National Center for Health Statistics' National Health and Nutrition Examination Survey.

They found that insured people have a significantly higher probability of being diagnosed than similar people without insurance - by 14 percentage points for diabetes and high cholesterol, and 9 points for high blood pressure. Among those already diagnosed, having insurance was associated with significantly healthier levels of blood sugar, total cholesterol, and systolic blood pressure.

These results imply that the expected gains in insurance coverage from the Affordable Care Act could translate into 1.5 million more people with a diagnosis of at least one of these chronic conditions and 659 thousand fewer people with uncontrolled cases.

Study: Estimating The Potential Impact Of Insurance Expansion On Undiagnosed And Uncontrolled Chronic Conditions, Daniel R. Hogan, Goodarz Danaei, Majid Ezzati, Philip M. Clarke, Ashish K. Jha and Joshua A. Salomon, Health Affairs, doi: 10.1377/hlthaff.2014.1435, published September 2015.