global burden of dz online course

How can we measure disease at the global level?

(Global Burden of Disease)

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Assistant professor Dr. Seo Ah Hong

ASEAN Institute for Health Development

Health of individuals

Health of a population

Epidemiological Tools

• Mortality: IMR, MMR

• Morbidity (Prevalence, incidence)

• Life expectancy

• Disability-Adjusted Life Year (DALYs)

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Life expectancy

Life expectancy• The average number of years of life at a given age in a population if

the current mortality experience were to continue• “at a given age”; So, it varies by age

• Life expectancy at birth• The average number of years a new-born baby could expect to live if current

trends in mortality were to continue for the rest of the new-born's life

• How long they will live if conditions remain as in a country in a specific year during their whole lifetime?

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20 000 $2000 $200 $Income per person (comparable dollars per year)

100806040200Li

fe e

xpec

tanc

y (y

ears

)

1000

100

1Population(millions)

50 yearsBurundi

81 yearsSweden

GAPMINDER

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This came from Gapminder (http://www.gapminder.org/data/).

http://creativecommons.org/licenses/by/3.0/

100806040200

Age

(yea

rs)

SarahAnnJeanLizPierre

Burundi2007 84

7257

36

1

GAPMINDER

8



100806040200

Age

(yea

rs)


Burundi2007 84

7257

36

1

50 years

Calculate the mean…

1+36+57+72+845 = 50

GAPMINDER

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Life Expectancy



100806040200

Age

(yea

rs)


Burundi2007 84

7257

36

1

child

adult

old

So yes, 2 of 5get old in Burundi

GAPMINDER

10



100806040200

Age

(yea

rs)

SaraAntonJanLisaPer

How long will they live…

…if conditions remain as in Sweden in 2007during their whole lifetime?

2007Sweden

GAPMINDER

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100806040200

93

Age

(yea

rs)

SaraAntonJanLisaPer

Sweden2007

6377 84 88

63+77+84+88+935

=81

81 years

Calculate the mean…

GAPMINDER

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Question• The life expectancy is 31 years higher in Sweden (81 years) than in

Burundi (50 years). Why?

① Is it because all Swedes live 31 years longer than all Burundians?② Is it because some Swedes live much longer than all Burundians?

100806040200

Age

(yea

rs)

2007

But “dying young” in Swedenis very different

from “dying young” in Burundi

“To live long” in Swedenis almost the same as

“to live long” in Burundi

GAPMINDER

14This came from Gapminder.


Question• The life expectancy is 31 years higher in Sweden (81 years) than in

Burundi (50 years). Why?

① Is it because all Swedes live 31 years longer than all Burundians?② Is it because some Swedes live much longer than all Burundians?

Summary of Life expectancy

1) Life expectancy is an average :Most Burundi people get older than 65 years and some die in childhood.

2) Life expectancy is low when child deaths are common

:It is low in Burundi not because all die a bit earlier, but because some die much younger

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Do we need other estimates of disease burden?

Due to the rise in importance of chronic diseases as the leading cause of death, along with growing

numbers of the very old,

Both mortality rates and life expectancy are useful, but

They do not tell us anything about disease burden in people living with diseases

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Global Burden of Disease(GBD)

• The GBD study is a collaboration between the WHO, the World Bank and the Harvard School of Public Health.

• The concept was firstly published in 1996.• It attempts to estimate the total burden due to

diseases. • Constituting the most comprehensive and

consistent set of estimates of mortality and morbidity yet produced.

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Disability-Adjusted Life Years (DALYs)

•A single indicator of total disease burden•Combining information about mortality and morbidity in a single number.

•Internationally accepted measure of death and disability

•Increasingly cited as a powerful tool for decision makers in international health.

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Disability-Adjusted Life Years (DALYs)

Interpretation: One DALY = one lost year of healthy life

Ideal health

Current health DALY

All deaths are equal?

• “Premature” death deserves special attention• Years of Life Lost (YLL) due to premature death

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YLL= N X L

N = number of deathsL = standard life expectancy at age of death in years

Death is not the only thing that matters

Years of healthy life Lost due to Disability (YLD)

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YLD= I x L x DW

I = number of incident disability casesL = average duration of the case until remission or death (years)

DW = disability weight (the severity of the disease:0 (perfect health) to 1 (dead))

Disability-Adjusted Life Year (DALY)

Facilitate comparisons of different health states or health outcomes.

•Compare the health of one population with another – and allow decision makers to focus on health systems with the worst performance

•Compare the health of the same population at different points in time

•Compare the health of subgroups within a population - to identify health inequalities

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Disability-Adjusted Life Year (DALY)

Facilitate comparisons of different health states or health outcomes.

=> DALYs help to inform debates on priorities for health service delivery, research and planning.

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•Disease burden can be attributed to • specific diseases (e.g. HIV, TB, obesity,

diabetes) and• risk factors for ill health (unsafe sex,

overcrowding, smoking, excess cholesterol, low FV).

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Christopher JLM, and Alan DL. N Engl J Med 2013;369:448-57

Why are DALYs important?

• Allows to address PREVENTABLE DISEASES in each region of the world

- how much of risks to health could be avoided in future years.

• DALYs attempt to provide an appropriate, balanced attention to the

effects of non-fatal as well as fatal diseases on overall health.

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Summary of Disability-Adjusted Life Year (DALY)

• The sum of years of life lost and years of life lived with disability.

• A summary measure of overall disease burden in a population, combining mortality and disability.

• Measuring a health gap, relative to an “ideal” life expectancy

• Currently the best indicators available now to set priorities for resource allocation.

Thank you for your attention!!!

Three Questions are following^^

The life expectancy at birth in Burundi is 50 years

Question 1: What is correct?

(1) We will rarely see elderly people (>65) in Burundi

(2) We will still see a bunch of elderly people in Burundi

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The life expectancy at birth in Sweden is 81 yearsThe life expectancy at birth in Burundi is 50 years

Question 2: So, do most Swedes live 31 years longer than Burundian?

(1) Yes(2) No

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Question 3: Mark the following statements as either true or false on your answer sheet.

Quiz 1

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Question True False

1 Life expectancy at birth is strongly associated with mortality in childhood.

O O

2 DALYs capture the number of healthy years lost to disability only.

O O

3 The calculation of DALYs involves an index of the disability attributed to specific diseases

O O

global burden of dz online course

Healthcare