global health
aliala
muennigsu_wk04_03chap.pptx_.pptxGlobal Burden of Disease
Chapter 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
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
Leading Causes of Death by Disease Category & Country Classification
Leading Causes of Death by Economic Development
| Disease/injury | % Deaths in Low Income Countries | % Deaths in Middle Income Countries | % Deaths in High Income Countries |
| Ischemic heart disease | 6.1 | 13.7 | 15.6 |
| Stroke, CVD | 4.9 | 12.8 | 8.7 |
| Lower respiratory infections | 11.3 | 5.4 | 3.8 |
| Diarrheal diseases | 8.2 | 4.4 | X |
| HIV/AIDS | 7.8 | 2.7 | X |
| Tuberculosis | 4.3 | 2.4 | X |
| Road traffic accidents | X | 2.4 | X |
| Prematurity, LBW | 3.2 | X | X |
X: Not a top 10 cause of death in the category of countries
Child Mortality Rates by Cause & Region
Leading Causes of Death by Disease & Intervention
| Disease | Number of Deaths (millions) | Percent of all Deaths | Most Relevant Policies |
| Heart disease | 7.25 | 12.8 | Nutrition, transit, green cities |
| Stroke | 6.15 | 10.8 | Nutrition, transit, green cities |
| Pneumonia | 3.46 | 6.1 | Transit, green cities |
| COPD | 3.28 | 5.8 | Transit, green cities |
| Diarrhea | 2.46 | 4.3 | Sewage, sanitation, nutrition |
| HIV/AIDS | 1.78 | 3.1 | Preventive practices |
| Tuberculosis | 1.34 | 2.4 | Nutrition, medical care, housing |
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
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
Highest DALY Burden by Country Categories of Income
| Poorest Countries | Middle-Income Countries | Wealthy Countries |
| Pneumonia | Depression | Depression |
| Diarrhea | Heart disease | Heart disease |
| HIV/AIDS | Stroke | Stroke |
| Malaria | Accidents | Alzheimer’s disease |
| Premature birth | Pneumonia | Alcohol abuse |
| Depression | Emphysema | Hearing loss |
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
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 populations or settings
Requires making assumptions about other settings and whether your findings can be generalized
