Life expectancy is shorter in the United States compared with other wealthy nations because of its health care system -- and not obesity, smoking, homicide or vehicle accidents, according to a study out Thursday.
In 1950, the United States ranked fifth for female life expectancy at birth, with only Australia, the Netherlands, Norway and Sweden doing better, according to the study by Peter Muennig and Sherry Glied of Columbia University, published in the journal Health Affairs.
But by 1990, the United States fell to 46th in the world for women's longevity, and by 2010 it ranked 49th for male and female life expectancy combined.
Americans are not dying younger -- the United States has achieved gains in 15-year survival rates between 1975 and 2005. However other countries have seen greater gains, the study said.
The researchers compared 15-year survival at age 45 and older, risk factors and per capita health care spending in the United States with Australia, Austria, Belgium, Britain, Canada, France, Germany, Italy, Japan, the Netherlands, Sweden and Switzerland.
All the comparison countries have universal health coverage, albeit with very different systems.
Smoking and obesity, the two most important behavior-related risk factors for health in the United States, were ruled out as culprits in the US drop in the rankings.
"The prevalence of obesity has grown more slowly in the United States than in other nations while smoking prevalence has declined more rapidly in the United States than in most of the comparison countries," the study says.
The number of deaths from homicide and traffic accidents remained stable over time, meaning those two causes of death were ruled also out.
So the researchers turned their attention to per capita health care spending.
Muennig and Glied found that per capita health spending in the United States increased at nearly twice the rate in other wealthy nations between 1970 and 2002.
The United States now spends well over twice the median expenditure of industrialized nations on health care, and far more than any other country as a percentage of its gross domestic product, the study found.
But "the unusually high medical spending is associated with worsening, rather than improving, 15-year survival."
That could be because, as health spending rises, "so too does the number of people with inadequate health insurance," they say in the study.
High spending on health care could be "choking off public funding on more important life-saving programs," such as public health and public safety programs, they added.
And they said Americans' over-reliance on specialty medical care and the country's system of unregulated fee-for-service reimbursement may be contributing to high US health spending and leading to unneeded procedures -- which in turn could cause complications and lead to more expenses.
Study authors "speculate that the nature of our health care system -- specifically, its reliance on unregulated fee-for-service and specialty care -- may explain both the increased spending and the relative deterioration in survival."
If so, then meaningful health care reforms may save money over the long term and also also save lives, the authors said.