I recently suggested that more people have died from lack of health insurance since 1994 (when Congress last defeated health care reform) than died during those years as a result of the first Gulf War, the Iraq War, the Afghanistan war, the 9/11 attacks, Hurrican Katrina and all of the nation’s homicides– combined.
Some have asked how it could be that lack of health insurance could so cause so many deaths. Here are some excerpts from one of the reports (from the Institute of Medicine) which gives a few examples of how this happens:

“Uninsured cancer patients generally have poorer outcomes and die sooner than persons with insurance. Without timely preventive screenings, diagnosis is de-layed. As a result, when cancer is found, it is relatively advanced and more often fatal than it is in persons with health insurance coverage. For example, uninsured women with breast cancer have a 30 to 50 percent higher risk of dying than women with private health insurance. Furthermore, once diagnosed, treatment disparities persist. For example, uninsured women are less likely to receive breast-conserving surgery….”
“Diabetes: Uninsured adults with diabetes are less likely than those insured to receive the professionally recommended standard of care for monitoring blood glu-cose levels and other complications. Uncontrolled blood glucose levels puts per-sons with diabetes at increased risk of hospitalization and additional complica-tions (e.g., heart and kidney disease) and disability (e.g., amputations and blind-ness). It is hard to imagine, but 25 percent of persons with diabetes go without a checkup for two years if they have been without health insurance for a year or more….”
“Acute Cardiovascular Disease: Uninsured patients with acute cardiovascular disease are:
• less likely to receive angiography or revascularization procedures,
• less likely to be admitted to a hospital that performs these diagnostic and treatment procedures, and
• more likely to die in the short term.”

There are at least three studies from three organizations that have attempted to assess this question. They are:
American Journal of Public Health / Cambridge Health Alliance (45,000 deaths)
Institute of Medicine (18,000)
Urban Institute (22,000)
I will add studies as I get them — including any scientific studies proving fatality levels related to national health care in other countries (I have not seen such studies yet).