A person can be healthy…but can a country
be healthy? Population health indicators measure the distribution
of health throughout a given population. These kinds of indicators are what sociologists
use to study patterns in health outcomes across
different social groups. Because, like all things sociological, we
want to understand the wider patterns of health. So, if you’re trying to figure out your own risks for a
disease, it might be useful to know the average number
of people like you who have contracted that disease. Or if you’re a policymaker trying to figure out
which diseases to spend money and time on, you might want to know which disease has
the highest mortality rates in your country. As we talked about last time, there are lots
of factors that can affect your personal health –
and those factors often vary by social group. So when we explore population health across
social dimensions like age, gender, race, ethnicity,
class or religious beliefs, we come up with differences in what health
looks like for that group. Let’s start by talking about what some of the
important indicators for population health are, and see what these indicators tell us
about health in the United States. [Theme Music] When we talk about the importance of
health, there’s an underlying implication here:
humans don’t want to die. The healthier you are, the more likely you
are to put off a visit from the grim reaper. Which is why we use the length of someone’s
life as one indicator of how healthy they are. One crude indicator of a population’s health is
life expectancy – the average number of years
an individual can be expected to live. And you can use life expectancy to get a
better understanding of what kind of person
tends to live longer, which is a pretty good proxy for the
overall health of a community. For example, in the United States, and for
that matter, almost every other country on the
planet, women tend to outlive men. For men in the United States, the average life
expectancy at birth is 76.3 and for women, it’s 81.2. And White Americans tend to live longer than
Black Americans. 79 is the life expectancy for White Americans,
whereas for Black Americans the number is
quite a bit lower: 75.5 In addition to helping us to understand the overall
health of the population, or portions of it, life expectancy
also tells us something about its future. Do we expect to have more elderly citizens
in the future? If people live longer, what does that mean
for the retirement age? This has implications for the structure of work
and leisure and helps when planning the costs of
things like social security and medicare. Another important population statistic is
the birth rate for different populations. Just as life expectancy helps us answer questions
that go beyond health, the birth rate tells us about more
than just the reproductive health of a population. There are a couple different ways to measure
the number of kids being born. One is a straight birth rate: in a given
year, how many live births are there for every
thousand people? But that might not be the right measure. After all, if people are living a lot longer,
there are going to be more people who are
living past child-bearing age. This would make the birth rate go down, even if the
number of kids each generation has stays constant. Because of this, we might use what’s called a total
fertility rate: the number of live births for every 1000
women between the ages of 15 and 44. Total fertility rates let us compare birth
patterns across generations. A larger generation might have more kids –
after all, more parents means more kids – but there
might be fewer kids per person, or vice versa! The number of births per year in the US has
been declining over the last 50 years. Some of that is because there are fewer women
of childbearing age now than there were when
the Baby Boomers were having kids. But even If we look at the total fertility
rate, that has also gone down, from 68.4 births per 1000 women of
childbearing age in 1980, to 62.5 births per
1000 women of childbearing age in 2015. Now, if we split up the population up by race,
we see big differences in the total fertility rate. It’s highest for Hispanic Americans, at 71.5 births
per 1000 women, and lowest for non-Hispanic
White Americans, with a total fertility rate of 59.3. And even here you can see the influence of
society on human procreation. Access to things like contraception and prenatal
care, and cultural traditions, shape the number
of children that are born. So, birth rates tell us about the categories
of people entering our society, but we might
also care about who is leaving us, too. Mortality rates are death rates in a given
population, and they can tell a lot us about
its overall health. For example, infant mortality rates are often
a key indicator of a group’s health. Because infants are especially vulnerable
to disease and malnutrition, their mortality rate tells us something about
broader issues, like poverty levels, and availability
and quality of food, water, and health services. For example, Black Americans are more than
twice as likely as White Americans to die in infancy, partially because these children are more
likely to be born in lower income families. Lower economic standing generally means
less access to health care, and there’s clear evidence that Black Americans
are much less likely to have access to quality prenatal
care than other racial and ethnic groups. Overall mortality rates can also help us understand
the pace of deaths in a community: in a given year, how many people in that group
have died as a fraction of that population? Mortality rates tend to be higher for men
than women, and higher for Black Americans
than White Americans… which might not too surprising given what we
learned about life expectancies for those groups earlier. In the US, the leading causes of mortality
for both men and women of all races are heart
disease and cancer. But what kills men and what kills women differs
a bit as we get further down the list of leading
causes of death. Men are much more likely to die from an unintentional
injury or accident than women are and also have
much higher suicide rates than women. There are mortality differences by race as
well, with Black men more likely to die from
homicide than other groups. Drilling down into this data a little more, we can also
understand population health by looking at the types
of diseases that different groups are susceptible to. Morbidity refers to the presence of disease,
while morbidity rates tell us something about the
frequency of disease within a given population. Diseases can also be co-morbid, meaning that
two diseases coexist in a person at the same time. Comorbidity rates tell us how common it
is for people in a population to have any two
diseases at one time. One thing to note here: incidence of a disease is
not the same thing as the prevalence of a disease. Incidence refers to the number of new cases reported
in a given time frame, whereas prevalence refers to the
number of existing cases in the population. So, put another way, incidence tells you how
likely you are to contract a disease. Prevalence tells you how many people already
have it. And I’m sure it won’t surprise you to hear that
morbidity rates within a society can vary a lot across
demographic groups for a number of reasons, like the racial makeup of a society or the
age profile of those people. Different subpopulations may have different
genetic makeups that can influence health. For example, Ashkenazi Jewish ancestry is
associated with higher rates of BRCA-1 mutations,
which is a genetic risk factor for breast cancer. Different populations may also be exposed to
health risks resulting from their physical environments,
like the neighborhood they live in. For example, Black children in the US have
higher asthma rates relative to White children, partly because of higher exposure to environmental
toxins in their homes and neighborhoods. But it can be hard to separate the effects of
something like pollution from other aspects of where
a person lives that might also affect their health. People who live in poorer neighborhoods are
more likely to be exposed to more pollution – so is it the pollution or the poverty
that leads to worse health outcomes? Let’s go to the Thought Bubble to look at
this question more closely. Three American economists, Janet Currie, Michael
Greenstone, and Enrico Moretti figured out a way to separate out the effects of
pollution on kids’ health by looking at what happened
when the government cleaned up toxic waste sites. All across the United States there are places
known as Superfund sites – areas that the government has deemed so polluted
that it requires an expensive, government funded
cleanup to make the place habitable. As of 2015, the EPA found that 53 million Americans
live within 3 miles of a Superfund site, including
about 18% of children under the age of 5. Currie, Greenstone, and Moretti compared health
outcomes for children who were born near a Superfund
site either before or after it was cleaned up and found that kids born after the clean up
were 20% less likely to be born with a congenital
anomaly, like heart murmurs. Since the only thing that had changed with the
clean up was the level of pollution, this study tells us
something you might already have guessed: being exposed to toxic chemicals at a young
age can be really damaging to your health. Thanks Thought Bubble. There are lots of environmental risks that
can be damaging to your health – houses with
lead paint, second hand smoke, smog. Because these risk factors tend to be more
common in low income areas, they disproportionately
affect less educated and minority Americans. And low income Americans are also more likely to
experience social environments that pose health risks. For example, the amount of stress a person
is under can have a big effect on both their
mental and physical well-being. And these groups are more likely to live or work in
high stress environments, like neighborhoods with
higher crime rates, or unfulfilling jobs with long hours. Another social factor that affects health?
Racism and discrimination. Sociologist David Williams has connected this unique
psychosocial stressor to increased rates of stress-
related disease morbidity among African Americans, like heart disease that may contribute to
higher risks of early mortality. All of these factors – the individual risk
factors, environmental risk factors, social risk
factors, and psychological risk factors – combine to help explain the health disparities we
see across different social groups in the US. Today, we learned about some of the indicators
that help us measure health for different populations, including life expectancy, birth rates,
mortality rates, and morbidity rates. Then, we talked about three contributors
to health disparities: individual factors like genetics, physical factors
like pollution, and social factors like stress. Crash Course Sociology is filmed in the Dr.
Cheryl C. Kinney Studio in Missoula, MT, and it’s
made with the help of all of these nice people. Our animation team is Thought Cafe and Crash
Course is made with Adobe Creative Cloud. If you’d like to keep Crash Course free for everyone,
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