- Life expectancy in the United States increased to 79.1 years in 2014
- Residents of counties in central Colorado can expect to live the longest
Health
begin quote from:
Life expectancy depends on where you live
Life expectancy differs by 20 years between some US counties
Story highlights
(CNN)Life expectancy at birth differs by as much as 20 years between the lowest and highest United States counties, according to new research published Monday in the medical journal JAMA Internal Medicine.
Dr.
Christopher J.L. Murray, lead author of the study and director of the
Institute for Health Metrics and Evaluation at the University of
Washington, estimated life expectancy for each US county from 1980
through 2014. Murray and his colleagues analyzed county-level data and
then applied a mathematical model to estimate the average length of
lives.
Life expectancy at birth
increased by 5.3 years for both men and women -- from 73.8 years to 79.1
years -- between 1980 and 2014, Murray and his colleagues wrote. During
that time period, men gained 6.7 years, from 70 years on average to
76.7 years, while women gained four years, from 77.5 years to 81.5
years.
But the numbers aren't the
same everywhere. Looking at the finer details, Murray and his colleagues
calculated a gap of 20.1 years between US counties with the lowest and
highest life expectancies.
The
counties with lowest life expectancy are located in South and North
Dakota, while counties along the lower half of Mississippi, in eastern
Kentucky, and southwestern West Virginia also showed lower life
expectancies compared to the rest of the nation. The North and South
Dakota counties include Native American reservations.
At the other extreme, residents of counties in central Colorado can expect to live longest, Murray and his colleagues said.
'Drastically different life expectancies'
While
the study does not directly answer why we see low or high life
expectancies in specific counties, it does look at what factors
contribute to the overall gap between some counties, said Murray.
"We
can see that many of the counties with very low life expectancies in
the Dakotas, like Oglala Lakota County in South Dakota, overlap with
large Native American reservations including the Pine Ridge and Rosebud
reservations," said Murray.
Conversely,
Summit County, Colorado, ranked as the county with highest life
expectancy in 2014 at 86.8 years, is home to several ski resort towns.
"For
both of these geographies, the drastically different life expectancies
are likely the result of a combination of risk factors, socioeconomics,
and access and quality of health care in those areas," said Murray.
Yet,
socioeconomic factors are not everything, said Murray, explaining that
"60% of the differences in life expectancy across counties can be
explained by socioeconomic factors alone" yet that leaves a "substantial
amount of unexplained differences."
"Behaviors
like smoking and physical activity, along with risk factors like
obesity and diabetes, are also very important," he said.
Still,
almost all counties throughout the nation showed improvement over time,
though the number of additional years varied across the nation.
Counties in central Colorado, Alaska and along both coasts experienced
larger increases than most other counties. Meanwhile some southern
counties in states from Oklahoma to West Virginia experienced either no
improvement or very little over time.
The
most positive note is that, over the study period, all counties show
declines in the risk of early death for children under the age of 5
years old, say the authors. And, nearly all counties (about 98%) show
declines in the risk of early death for people between the ages of 5 and
25, as well as those between 45 and 85.
However, people between the ages of 25 and 45 show an increased risk of death in 11.5% of counties over the study period.
The
study didn't evaluate what might drive changes in mortality risks for
specific age groups, Murray said, but he speculates that the same
general factors that impact life expectancy overall may drive
differences for those ages 25 to 45.
What
causes differences in life expectancy? The reasons for life span
inequality have been explored in previous studies so the current study
examined the extent to which just three factors contributed to lower or
higher survival. The three factors are socioeconomic levels and
race/ethnicity, behavioral and metabolic risk, and health care.
"Risk
factors -- obesity, lack of exercise, smoking, hypertension, and
diabetes -- explained 74% of the variation in longevity," said Murray.
"Socioeconomic factors, a combination of poverty, income, education,
unemployment, and race, were independently related to 60% of the
inequality, and access to and quality of health care explained 27%."
The
authors used new methodologies that are more precise than past models,
but county level data are all subject to error, the authors note. If
recent trends are allowed to continue, the differences in life
expectancy across counties will increase, not decrease, the researchers
add.
'A gap of 20 years ... is absurd'
For
the first time since 1993, US life expectancy in 2015 dropped
significantly for the entire population, not just certain groups, the
Centers for Disease Control and Prevention reported in late 2016. CDC researchers warned that a one-year shift does not mark a trend.
Ellen
Meara, a professor or health economist at the Dartmouth Institute for
Health Policy and Clinical Practice, said many factors impact life
expectancy. She was not involved in the new research.
"Socioeconomic
factors like education and poverty can shorten lives of individuals,
and it may be bad to live in areas with high rates of poverty and less
educated adults," said Meara. "Similarly, sedentary lifestyles (which
are reflected in obesity rates) and smoking are two of the biggest
individual risks of poor health and premature death. For people who
develop a disease like diabetes or hypertension, also measured in the
study at the county level, risk of death is higher."
Meara
noted that the authors used "rigorous methods" to gain a more
"comprehensive look" at deaths by county and age group. "This research
echoes what we have been learning from studies in other settings over
the past decade," she said. "Disparities in mortality have widened over
time."
Still, understanding
differences across geographic areas can provide clues, said Meara, about
what might contribute to improvements over time.
"To have a gap of 20 years in a country as wealthy as ours is absurd," she said.
Murray
agrees. "The inequality in health in the United States -- a country
that spends more on health care than any other -- is unacceptable," he
said. "Every American, regardless of where they live or their
background, deserves to live a long and healthy life."
No comments:
Post a Comment