Global health trends and burden of disease Flashcards
» Some concepts from demography that are important for public health:
- Population growth
- Fertility rates (birth rates)
- Life expectancy (death rates)
- Age structures and population pyramids
Population growth factors
» Fertility rates
- “Global fertility is projected to fall from 2.5 children per woman in 2019 to 2.2 in 2050.”
» Life expectancy
- “Life expectancy at birth is expected to rise from 72.6 years in 2019 to 77.1 years in 2050.”
» International migration
- “International migration is a much smaller component of population change than births or
deaths. However, in some countries and areas the impact of migration on population size is
signifcant.”
Fertility rates by country
» Some countries have
fertility rates as high as 5
or 6 live births per woman
» Other countries have
fertility rates as low as 1.5
live births per woman
Fertility rates
» In demography, fertility refers to the number of chldren that a woman has, rather than the
physical capability to produce chldren (which in demography is termed “fecundity”)
» The fertility rate is the number of children that a woman has, on average, in a given
population
» One metric that is used = “live births per woman”
“Why do some countries have low fertility rates and other countries have high fertility rates?”
Factors affecting fertility rates
» The invention of, and access to, modern contraception
- e.g. oral pill, implants, intrauterine devices (IUDs), condoms
» Woman’s empowerment, including education, employment, household decision-making
» Child survival rates, which may afect a family’s decision to have more or fewer children
Fertility rates by country
Factors afecting life expectancy
» The invention of, and access to, life-saving medical technologies, pharmaceuticals, and
other forms of health care
» Quality of life, including…
- Nutrition and healthy diets
- Clean water, sanitation, and hygiene
- Exposure to other risk factors
» Child mortality rates
Key points
» Understanding public health involves understanding demographic concepts such as
population growth, fertility rates, and life expectancy
» In some countries, fertility rates are very high (5 or 6 live births per woman) and the
population is still growing. In other countries, fertility rates are low (1.5 live births per
woman) and the population is no longer growing.
» Fertility rates and life expectancy are afected by similar factors, such as access to
contraception and health care, economic development, women’s empowerment, and quality
of life.
» For this reason, countries that have high fertility rates typically also have low life
expectancy; countries that have low fertility rates typically also have high life expectancy.
World age structure over time
Demographic transition photo
Demographic transition
» We saw before that… - Most countries that have high fertility
rates also have low life expectancy
- Most countries that have low fertility also
have high life expectancy
» Over time, as countries have experienced
technological progress and economic
development, fertility rates have
decreased and life expectancy has
increased
“…the historical shift from high birth rates and high death rates in societies with minimal
technology, education (especially of women) and economic development, to low birth rates and
low death rates in societies with advanced technology, education and economic development”
~ Wikipedia, Demographic transition
Age structures
» “Population pyramid”
» A representation of the age structure of a
population
» Horizontal bars show the proportion of the
population in diferent age categories
» Male and female on diferent sides
(usually)
» Youngest at bottom, oldest at top (usually)
» The demographic transition (the
shift from high birth rates and
high death rates, to low birth rates
and low death rates), results in
changes in age structures
(changing population pyramids)
Overview 2B lecture slides
» Disease classifcation
» Burden of disease
» Epidemiological transition
Key points
» Over time, as countries have experienced technological progress and economic
development, fertility rates have decreased and life expectancy has increased.
» This results in a shift in age structures, which is known as the “demographic transition”.
» Some countries (such as Australia) are in the late stages of the demographic transition and
now have low fertility rates and high life expectancy, and as a result, have an age structure
with as many older adults as younger children.
» Other countries (such as Mozambique) are in the early stages of the demographic transition
and still have high fertility rates and low life expectancy, and as a result, have an age
structure with more younger children than older adults.
» These changes in birth rates, death rates, and age structures are linked to many other
aspects of public health, including the prevalance of diferent diseases around the world.
Disease classifcation
» It is useful to be able to talk about diferent types of diseases
» Several diferent disease classifcation systems
- Communicable / non-communicable / injury
- International Classifcation of Diseases (ICD-9, ICD-10, ICD-11)
- More detailed disease categories used by WHO, GBD, others
Disease classifcation photo
International Classifcation of Diseases (ICD-11)
“The international standard for systematic recording,
reporting, analysis, interpretation and comparison of
mortality and morbidity data.”
“…allows countries to count and identify their most
pressing health issues.”
~ World Health Organisation
International Classifcation of Diseases (ICD-11) photo
Australia, causes of death photo
Key points
» We use disease classifcation systems to talk about diferent types of diseases
» One important classifcation is communicable vs non-communicable diseases (infectious vs
chronic diseases)
Burden of disease over time, australia
