Life Expectancy on Decline in Some U.S. Counties

It is common knowledge that average life expectancy in the United States is on the upswing. In fact, current statistics now estimate that men and women are living about six or seven years longer than they did four decades ago. While this reflects the trend for a large proportion of the U.S. population, a recent trend analysis conducted by HSPH associate professor of international health Majid Ezzati and his colleagues leads to the troubling finding that this is not the case for all areas of the country. In the April 22 PLoS Medicine, Ezzati and his group show that there are large sex-specific variations in mortality across the country, with some regions showing no improvement at all while a significant number of others even show a decline in life expectancy.

Courtesy Majid Ezzati

Lifetime gains and losses. Improvement in life expectancy (shades of gray and black) was more prevalent among U.S. counties in 1983 (left map) than in 1999 (right). In the intervening years, cross-county differences have become more apparent, with some counties showing no change in life expectancy (white) and others getting worse (shades of red). On the maps, the darker the color, the more extreme the change.

Ezzati and his group began this analysis by collecting mortality data for each U.S. county from the National Center for Health Statistics and population data from the U.S. Census. Ezzati explained that the advantage of looking at county-level data is that it provides a far better representation of mortality spread since it is the smallest geographical unit for which reliable measurements are available. County measurements also are relatively consistent over time.

Once the data had been gathered, the team was able to calculate the mortality rate for individual U.S. counties for each year since 1961. This produced more accurate estimations of life expectancy differences based on geographical location. Intriguingly, the researchers found an unusual pattern to the data. “It seemed that something started happening in the early 1980s,” said Ezzati. “After a couple of decades of mortality disparity going down, it then started to go up.” To investigate this more closely, Ezzati and his group separated the analysis into approximately 20-year time periods—one prior to and one after 1983 (the year that showed lowest cross-county mortality differences).

It appeared that in the 22-year period leading up to 1983, mortality rate seemed to be improving at a relatively similar pace across the United States. But in the 20-year period after 1983, life expectancy gains became more polarized than ever before. “Some counties started stagnating,” said Ezzati. “But the surprise was that there were a reasonably large number of counties that had gotten worse.”

This so-called “reversal of fortunes” in the worst-off counties does not reflect well on the U.S. health system, whose primary aim has been to improve the health of all populations in the country. Ezzati said, “Inequality aside, which is itself bad, the decline in life expectancy is a very troubling thing. We are now trying to look at the epidemiological drivers of this.”

—Yvonna Reekie

Perceptual Learning Based on Biphasic Brain Changes

As we struggle to pick out a familiar face in a busy crowd, identify objects on an X-ray image, or search for berries in a montage of leaves, it can sometimes feel a bit like playing Where’s Waldo? But, as in the game, the ability to identify a particular stimulus—seemingly invisible against a complex backdrop—usually becomes easier with experience or practice. This phenomenon is known as perceptual learning.

Previous studies exploring the neural mechanisms underlying perceptual learning have frequently thrown up conflicting results, with some researchers reporting increased brain activation within the primary visual cortex (V1) while others report no change. Now research from the lab of HMS assistant professor of radiology Yuka Sasaki, of Massachusetts General Hospital, has shed new light on these apparently contradictory findings—implying that previous studies could have been tapping into different stages of the same process.

Sasaki’s team reports in the March 27 Neuron the surprising finding that activity in the human V1 actually exhibits biphasic activity over the course of perceptual learning—increasing during the early phase then strangely disappearing, independent of behavior that continues to improve.

The team discovered this unusual effect by assessing brain activity at specific intervals over a prolonged period of training using functional magnetic resonance imaging (fMRI) while participants engaged in computer-based perceptual-learning experiments. The tasks required subjects to identify target stimuli (in a central or peripheral position) on a computer screen that was filled with horizontal bars. This test screen was repeatedly presented for a short period immediately followed by a blank and then a “masking” screen, composed of randomly oriented V shapes, which made perceiving the target stimuli on the test screen very difficult. Yet, with training, subjects soon became quicker at identifying the targets.

“It’s been known for some time that sensory-perception ability changes with practice, but the underlying neural mechanisms were not really known,” said Sasaki.
To investigate changes in brain responses, all participants were first scanned while performing the experiment, prior to any training, to get a measure of baseline V1 activity. Subjects were then scanned four times over a period of two weeks, with additional training outside the scanner in between scanning sessions.

By doing this, the researchers found that brain activity in V1 increased with initial learning, but then returned to the original level. Behavior, on the other hand, continued to improve even after changes in V1 had subsided.

“If neurons increased their firing more and more on repeated exposure to stimuli, eventually they would explode,” joked Sasaki. “Probably what happens is that during early perceptual learning, there are increased synapses between neurons, but then at some point there is a reorganization and a reduction in the number of inefficient synapses. Because fMRI cannot look at neural activity at the molecular level, this is still a hypothesis.”

—Yvonna Reekie

Sickest Patients Still Skip Pills Under Medicare Drug Benefit

A recent study finds that the results of the new Medicare Part D drug benefit—a program that for the first time offers Medicare recipients prescription drug coverage—are mixed. Both healthy and sick beneficiaries are now less likely to cut back on basic needs like food in order to pay for medicine. The sickest patients, however, who typically have high drug expenditures, are still skipping medications for financial reasons—despite the new benefit.

The study, which appears in the April 23 Journal of the American Medical Association, was based at the Department of Ambulatory Care and Prevention at HMS and Harvard Pilgrim Health Care.

“We’re seeing encouraging signs of relief, but the problem of unmanageable drug costs has by no means been eliminated,” said lead author Jeanne Madden, an HMS instructor in ambulatory care and prevention. “Medicare Part D is a work in progress, and more needs to be done to ensure that very sick individuals get the drugs they need.”

This is the first nationwide study to examine the effect of the Medicare Part D drug benefit on financial hardship since the benefit took effect in January 2006. The new benefit was the largest expansion of the Medicare program since enactment in 1965. More than half of Medicare beneficiaries enrolled in Part D, which was intended to increase access to needed medications, especially among the poor and chronically ill. About 10 percent of beneficiaries still have no drug coverage. Reports have estimated that about 30 percent of beneficiaries had no drug coverage prior to Part D.

In the current study, the investigators examined responses from 24,234 Medicare enrollees who participated in the Medicare Current Beneficiary Survey from 2004 through 2006. More than 72 percent of the beneficiaries had at least two chronic illnesses. The study found that the rate of skipping pills and prescriptions due to cost declined from 14.1 percent of beneficiaries in 2005 to 11.5 percent in 2006. Spending less on basic needs to afford medicine declined from 11.1 percent to 7.6 percent over the same period.

But the sickest patients, who skipped pills at about twice the rate of healthier patients in 2004 and 2005, experienced no improvements in pill-skipping after Part D began, even though they were less likely to cut back on basic necessities to pay for medicine after Part D. This group was more likely to encounter the benefit’s coverage gap, sometimes called the “doughnut hole,” a peculiar feature of Part D. During 2006, once a beneficiary’s drug expenses reached $2,250, he had to pay the full cost of his medications until his expenses hit $5,100, at which point Medicare covered 95 percent of drug expenses. (As of 2008, the gap is between $2,510 and $5,726.)

“Plugging the doughnut hole is a first step to reduce pill-skipping among the sickest patients,” said the study’s principal investigator, Stephen Soumerai, an HMS professor of ambulatory care and prevention. “Such coverage gaps cut off access to life-saving drugs.”

—Yvonna Reekie

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