Americans are living longer than they did two decades ago, a new study shows, but they are losing ground in key measures of health status to counterparts in other developed nations around the globe.

The findings, from the first major analysis of the health status of the U.S. population in more than 15 years, show progress in reducing death rates, adjusted for age, across a variety of diseases. But death rates from illnesses associated with obesity, such as diabetes and kidney disease, as well as neurological conditions like Alzheimer's disease, are on the rise.

In addition, years of living with chronic disability, an indicator of quality of life, increased for the average American over the past 20 years, partly reflecting the aging of the population.

"Individuals in the United States are living longer, but not necessarily in good health," said the researchers, led by Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington, Seattle.

The study was published online Wednesday by JAMA, the Journal of the American Medical Association.

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