Global burden of disease analysis examines the amount of suffering and death from diseases in populations to inform health policies and investments. It measures both mortality (deaths) and morbidity (non-fatal health outcomes) using metrics like disability-adjusted life years (DALYs). Leading global causes of death vary by factors like location, income level, and disease category. Burden of disease analysis and cost-effectiveness analysis can optimize health outcomes within budgets by comparing interventions. Validity concerns include accurately measuring relationships internally within a study and generalizing results externally to other populations.
3. Key Ideas
Global health community needs to shift focus from how many
people get sick to why they are sick and what can be done
Burden of disease analysis tells how much suffering and death
exists among a group
Cost-effectiveness analysis tells us how many lives we can save
with a given amount of money
4. Burden of Disease
How much disease and death are present in a given place or
among a group of people
How do we decide where to intervene?
Geography (e.g., Latin America)
Income (e.g., countries with low GDP)
Burden of disease analysis can help inform the kinds of policies
and investments that will have the greatest impact on disease
burden
7. Leading Causes of Death by Economic
DevelopmentDisease/injury% Deaths in Low
Income Countries% Deaths in Middle Income Countries%
Deaths in High Income CountriesIschemic heart
disease6.113.715.6Stroke, CVD4.912.88.7Lower respiratory
infections11.35.43.8Diarrheal
diseases8.24.4XHIV/AIDS7.82.7XTuberculosis4.32.4XRoad
traffic accidentsX2.4XPrematurity, LBW3.2XX
X: Not a top 10 cause of death in the category of countries
9. Leading Causes of Death by Disease &
InterventionDiseaseNumber of Deaths (millions)Percent of all
10. DeathsMost Relevant PoliciesHeart disease7.2512.8Nutrition,
transit, green citiesStroke6.1510.8Nutrition, transit, green
citiesPneumonia3.466.1Transit, green
citiesCOPD3.285.8Transit, green citiesDiarrhea2.464.3Sewage,
sanitation, nutritionHIV/AIDS1.783.1Preventive
practicesTuberculosis1.342.4Nutrition, medical care, housing
11. Alternative Ways of Measuring Life
Death at age 3 may be different than death at age 83
Conditions that do not cause death directly or cause death rarely
do not show up in mortality rankings but may still be public
health issues
e.g., Depression, migraine headaches
Potentially important components:
Years of life lost
Quality of life lived with disease
12. Measures of Disease Burden
Quality adjusted life year (QALY): accounts for morbidity and
mortality; one QALY is equivalent to one year lived in perfect
health
All conditions are score from 0 (death) to 1 (perfect health) and
applied to the years lived with the condition
Based on general population’s ratings
Disability adjusted life year (DALY)
Conditions scored from 0 (perfect health) to 1 (death)
Based on ratings by health experts
13.
14. Highest DALY Burden by Country Categories of IncomePoorest
CountriesMiddle-Income CountriesWealthy
CountriesPneumoniaDepressionDepressionDiarrheaHeart
diseaseHeart
diseaseHIV/AIDSStrokeStrokeMalariaAccidentsAlzheimer’s
diseasePremature birthPneumoniaAlcohol
abuseDepressionEmphysemaHearing loss
15. Cost-effectiveness Analysis
Method to maximize the number of adjusted life years (QALYs
or DALYs) within a given budget
Cost-benefit analysis: places a dollar value on the health
outcome and compares cost of intervention to no intervention
Compares relative costs of different interventions
League table commonly constructed to visualize options and
make decisions
16. Validity
Internal validity: measuring variables accurately so that
conclusions reached within a study are true (valid)
Requires correct temporal (time) sequence between exposure
and outcome, accounting for other factors that could confound
the relationship
External validity: applying the results of one study to other