This document discusses global disease burden and methods for measuring and comparing the impacts of different diseases. It introduces the Global Burden of Disease database developed by Harvard University to assess overall health loss from diseases, injuries, and risk factors using metrics like disability-adjusted life years (DALYs). DALYs consider both years of life lost due to premature mortality and years lost due to disability. The document provides examples of DALY calculations and shows data on leading causes of death and disease burden globally and in different country income levels. It discusses trends over time in life expectancy, causes of death, and population growth.

1. Global Disease Burden:
Dr Zahid Khan
King Faisl University,KSA.

2. Two public health questions:
• What is the total impact of disease and injury in
the population? -- the overall target for public
health interventions?
• How do we compare the impacts of different
diseases, risk factors, and interventions that
affect different populations?

3. Ultimate Measure of Ill-health?
• Death is most common
• Easy to determine
• Commonly tabulated
• Severe problems
• Everyone dies
• Health never achieved
• Age is clearly important
• Deaths + Illness = ?

4. Global Burden of Disease
Database
• Developed at Harvard University originally for the World
Bank
• Extended greatly in the mid-1990s and now adopted by
the World Health Organization
• Dozens of countries now have NBDs

5. Quality Adjusted Life Years
QALY
• Basically the number of fully healthy life years lost
to a particular disease or risk factor.
• Considers the age at which the disease or death
occurs and the duration and severity of any
disability created.

6. Disability Adjusted Life Year
The DALY, a kind of QALY
• The only differences in the rating of a death or
disability should be due to age and sex, not to
income, culture, location, social class.
• Everyone in the world has right to best life
expectancy in world
• DALY = YLL + YLD
• Years of Lost Life (due to mortality)
• Years Lost to Disability (due to injury & illness)

7. Schema for Assessing Non-fatal
Health Outcomes
Disease
Impairment
Disability
Handicap
Polio
Paralyzed legs
Inability
to walk
Unemployed
Difficulty
learning
Social isolation
Brain
injury
Mild mental
retardation

8. Disability Adjusted Life Year
The DALY,s calculation.

9. Sample DALY Calculations
Diseases A and B
• A. 100,000 children are stricken for 1 week with a
disability weighting of 0.3; 2% die at 1 year old.
• B. 100,000 adults are stricken for 2 years with a
disability weighting of 0.6; 20% die at 80 years old.
• A: YLL (= 2000 x 80) + YLD (=100k x (7/365) x 0.3) =
160,000 + 575 = 160,600
• B: YLL (= 20,000 x 1) + YLD (=100k x 2 x 0.6) = 20,000
+ 120,000 = 140,000

10. Definitions
• Impairment: loss or abnormality of
psychological, physiological, or anatomical structure or function
• Disability: any restriction or lack of ability to perform an activity
in the manner or within the range considered normal.
• Handicap: disadvantage resulting from impairment or disability
that limits or prevents the fulfillment of a role that is normal
(depending on age, sex, social, and cultural factors).

11. Deaths attributed to 19 leading factors,
by country income level, 2004

12. Percentage of disability-adjusted life years (DALYs)
attributed to 19 leading risk factors, by country
income level, 2004

13. Changing in causes of death
Percentage distribution
1909
Respiratory
Diseases
Cardiovascular
diseases
Source: WHO 1999
Other
Infectious
Diseases
TB
Diarrhoeal
Diseases
Injuries
1999
Cancer

14. Expectation of life at birth (years)
Life expectancy trends
90
80
More developed
70
World
60
Less developed
Least developed
50
40
30
1950
1960
1970
1980
1990
2000
2010
2020
2030
2040 2050
Period
Source: Population division of the Dept. of Economic and Social Affairs, United States Secretariat (2003). World Population Prospects: The
2002 Revision Highlights. New York: United Nations.

15. Population growth
9
Billions
8
7
6
5
4
3
2
1
Developed countries
1
9
5
1 0
9
5
1 5
9
6
1 0
9
6
1 5
9
7
1 0
9
7
1 5
9
8
1 0
9
8
1 5
9
9
1 0
9
9
2 5
0
0
2 0
0
0
2 5
0
1
2 0
0
1
2 5
0
2
2 0
0
2
2 5
0
3
2 0
0
3
2 5
0
4
2 0
0
4
2 5
0
5
0
0
Developing countries
Source: United Nations Populations Division, World Population Prospects, The 2004 Revision, medium variant.

16. Conclusions
• Inequality
• Universal coverage
• Nutrition transition: high levels of child under-nutrition and
adult obesity coexist
• Double burden of diseases
• Communicable, maternal, perinatal and nutritional
conditions
• Non communicable diseases
• Injuries
• Health promotion can play important role

17. Any Queries !!!
•
Thank You