13th September 2013

Americans living longer, healthier lives

Overall, Americans today are living longer and more healthily than the previous generation, according to one of the most comprehensive studies of its kind. There was a 3.8 year increase in average life expectancy during the last two decades, with quality-adjusted life expectancy (QALE) also increasing. However, there was a notable rise in anxiety among young and middle-aged people, beginning in 2001.

Thanks to medical advances, better treatments and new drugs not available a generation ago, the average American born today can expect to live 3.8 years longer than a person born two decades ago. Despite all these new technologies, however, is our increased life expectancy actually providing more active and healthy years of life? That question has remained largely unanswered – until now. In a first-of-its-kind study, the University of Massachusetts Medical School has found that the average 25-year-old American today can look forward to 2.4 more years of healthy life than 20 years ago while a 65-year-old today has gained 1.7 years.

Synthesising data from multiple government-sponsored health surveys conducted over the last 21 years, the researchers were able, for the first time, to measure how the quality-adjusted life expectancy (QALE) of all Americans has changed over time. The study’s findings are described in a paper published yesterday in the American Journal of Public Health.

“QALE tells us more than how long a person can expect to live,” said Dr. Allison Rosen, associate professor of quantitative health sciences. “It tells us what the relative qualities of those added years are in terms of physical, emotional and mental well-being. Though many studies have measured this in different ways, this is really the first time we’ve been able to capture this type of information across the whole U.S. population over an extended period.”

Overall, the data shows that Americans are living longer, reporting fewer symptoms of disease, have more energy and show less impairment in everyday tasks than a generation ago. According to the study, a 25-year-old person today can expect to live 6 percent or 2.4 quality years longer than their 1987 counterpart. Meanwhile, a 65-year-old person will gain 1.7 quality years, a 14 percent increase from a generation ago.

Thanks to improvements in health care, many conditions are far more treatable today than 25 years ago, Rosen said. Heart disease, for instance, was potentially much more debilitating a generation ago and patients often suffered a decline in quality of life as a result. “Today, it is far less likely that a patient recovering from a heart attack will become institutionalised or need around-the-clock care the way they once might have,” Rosen said.

Today, Americans are more likely to see quality of life declines related to chronic, degenerative diseases such as Alzheimer’s and dementia, while younger Americans appear to be experiencing problems related to a sedentary lifestyle. The authors also identified some troubling health trends. Among these was an increase in anxiety among young and middle-aged people, beginning in 2001. They also found that health gains made as a result of smoking cessation programs were being off-set, in part, by increases in obesity.

In the past, researchers have had a difficult time measuring population health beyond simple life expectancy because quality of life incorporates so many variables – physical well-being, mental health, pain, vitality, energy, emotional state – that it’s difficult to bring all these things together cohesively into a single number. Making it even more challenging, surveys measuring quality of life are rarely consistent with each other as they all define health and life quality differently.

Using multiple national surveys that asked Americans about their health in various ways over the last 21 years, Rosen and her colleagues solved this problem by identifying areas where the studies overlapped – allowing them to build a single, large data set that covered the entire adult population over more than two decades.

“Comprehensive measures of the overall health of the nation are practically non-existent,” said Rosen. “This study shows how existing national data can be used to systematically measure whether the population is getting healthier – not just living longer.”

As the Affordable Care Act (ACA) goes into effect from 2014–2020, the value of a single, consistent way of measuring improvements in health over a large population will be invaluable in assessing the impact of these pending changes, according to the authors.

“Having a consistent measure of population health represents a major advance in our ability to measure the impact of health care reform on the health – not just the health care use – of all Americans,” said Rosen. “The bottom line in assessing the success of the ACA is whether or not we are getting the most health from our investment of increasingly limited resources. Are we getting the most health bang for our bucks?”

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