Case 01 – International burden of disease
Learning goals:
1. What is public health? (definition, short; why is it important?)
Public health is the science and art of preventing disease, prolonging life and promoting
health through the organized efforts of society. The goals of public health is the biologic,
physical and mental well-being of all members of society, regardless of gender, wealth,
ethnicity, sexual orientation, country or political views.
It is important for a number of things. Public health plays a role in:
1. Prevent disease and its progression, and injuries
2. Promote healthy lifestyle and good health habits
3. Identify, measure, monitor and anticipate community health needs (e.g. surveillance)
4. Investigate and diagnose health problems, including microbial and chemical hazards
5. Formulate, promote and enforce essential health policies
6. Organize and ensure high-quality, cost-effective public health and health services
7. Reduce health disparities and ensure access to healthcare for all
8. Promote and protects a healthy environment
9. Disseminate health information and mobilize communities to take appropriate action
10. Plan and prepare for natural and man-made disasters
11. Reduce the impact of interpersonal violence and aggressive war
12. Conduct research and evaluate health-promoting/disease-preventing strategies
13. Develop new methodologies for research and evaluation
14. Train and ensure a competent public health workforce
15. Evaluate the effectiveness
16. Promote health
Areas of key priorities are:
- Health systems
- Mental health crisis
- Substance abuse
- Infectious diseases
- Malnutrition and food insecurity
- Sexual and reproductive health challenges
- Climate change
- Cancer
- Diabetes
, 2. What are QALY, DALY and HEALYs? (How are they measured? What does it entail?)
QALYs = quality-adjusted life years
The quality-adjusted life year is a generic measure of disease burden, including both the
quality and the quantity of life lived. It is used in economic evaluation to assess the value of
medical interventions. One QALY equates to one year in perfect health. QALY scores range
from 1 (=perfect health) to 0 (=death). QALYs can be used to inform health insurance
coverage determinations, treatment decisions, to evaluate programs and set priorities for
future programs.
The QALY is a measure of the value of health outcomes to the people who experience them.
It combines two different benefits of treatment – length of life and quality of life – into a
single number that can be compared across different types of treatments.
Calculating a QALY requires two inputs: one is the utility value (or utility weight) associated
with a given state of health by the years lived in that state. The underlying measure of utility
, is derived from clinical trials and studies that measure how people feel in these specific
states of health. The way they feel in a state of perfect health equates to a value of 1 (or
100%). Death is assigned a utility value of 0 (or 0%), and in some circumstances, it is possible
to accrue negative QALYs to reflect health states deemed ‘worse than dead’. The value
people perceive in less than perfect states of health is expressed as a fraction between 0 and
1. The second input is the amount of time people live in various states of health. This
information usually comes from clinical trials.
A QALY is measured via the following formula: Years of life x Utility value
1 = perfect health; 0 = death
For example: a new cancer drug extends a patient’s life by 3 years, but with side effects that
reduce their quality of life to 0.7. QALY = 3 years x 0.7 = 2.1 QALYs
So, the interventions provides 2.1 QALYs.
DALYs = disability-adjusted life years
It is a measure of overall disease burden, expressed as the number of years lost due to ill-
health, disability or early death. It was developed in the 1990s as a way of comparing the
overall health and life expectancy of different countries.
The DALY has become more common in the field of public health and health impact
assessment (HIA). It not only includes the potential years of life lost due to premature death,
but also includes equivalent years of ‘healthy’ life lost by virtue of being in states of poor
health or disability. In doing so, mortality and morbidity are combined into a single, common
metric.
A Daly is measured via the following formula: DALY = YLD + YLL
Years lived with Disability (YLD) = number of deaths multiplied by standard life
expectancy at age of death.
Years of Life Lost (YLL) = number of incident cases multiplied with disability weight,
multiplied by average duration of the case until remission
For example, 1 person dies at age 50 due to a disease, and the life expectancy is 80. Another
10 people suffer from the disease for 5 years, with a disability weight of 0.4.
YLD = 10 x 5 x 0.4 = 20 years
YLL = 1 death x (80-50) = 30 years
Learning goals:
1. What is public health? (definition, short; why is it important?)
Public health is the science and art of preventing disease, prolonging life and promoting
health through the organized efforts of society. The goals of public health is the biologic,
physical and mental well-being of all members of society, regardless of gender, wealth,
ethnicity, sexual orientation, country or political views.
It is important for a number of things. Public health plays a role in:
1. Prevent disease and its progression, and injuries
2. Promote healthy lifestyle and good health habits
3. Identify, measure, monitor and anticipate community health needs (e.g. surveillance)
4. Investigate and diagnose health problems, including microbial and chemical hazards
5. Formulate, promote and enforce essential health policies
6. Organize and ensure high-quality, cost-effective public health and health services
7. Reduce health disparities and ensure access to healthcare for all
8. Promote and protects a healthy environment
9. Disseminate health information and mobilize communities to take appropriate action
10. Plan and prepare for natural and man-made disasters
11. Reduce the impact of interpersonal violence and aggressive war
12. Conduct research and evaluate health-promoting/disease-preventing strategies
13. Develop new methodologies for research and evaluation
14. Train and ensure a competent public health workforce
15. Evaluate the effectiveness
16. Promote health
Areas of key priorities are:
- Health systems
- Mental health crisis
- Substance abuse
- Infectious diseases
- Malnutrition and food insecurity
- Sexual and reproductive health challenges
- Climate change
- Cancer
- Diabetes
, 2. What are QALY, DALY and HEALYs? (How are they measured? What does it entail?)
QALYs = quality-adjusted life years
The quality-adjusted life year is a generic measure of disease burden, including both the
quality and the quantity of life lived. It is used in economic evaluation to assess the value of
medical interventions. One QALY equates to one year in perfect health. QALY scores range
from 1 (=perfect health) to 0 (=death). QALYs can be used to inform health insurance
coverage determinations, treatment decisions, to evaluate programs and set priorities for
future programs.
The QALY is a measure of the value of health outcomes to the people who experience them.
It combines two different benefits of treatment – length of life and quality of life – into a
single number that can be compared across different types of treatments.
Calculating a QALY requires two inputs: one is the utility value (or utility weight) associated
with a given state of health by the years lived in that state. The underlying measure of utility
, is derived from clinical trials and studies that measure how people feel in these specific
states of health. The way they feel in a state of perfect health equates to a value of 1 (or
100%). Death is assigned a utility value of 0 (or 0%), and in some circumstances, it is possible
to accrue negative QALYs to reflect health states deemed ‘worse than dead’. The value
people perceive in less than perfect states of health is expressed as a fraction between 0 and
1. The second input is the amount of time people live in various states of health. This
information usually comes from clinical trials.
A QALY is measured via the following formula: Years of life x Utility value
1 = perfect health; 0 = death
For example: a new cancer drug extends a patient’s life by 3 years, but with side effects that
reduce their quality of life to 0.7. QALY = 3 years x 0.7 = 2.1 QALYs
So, the interventions provides 2.1 QALYs.
DALYs = disability-adjusted life years
It is a measure of overall disease burden, expressed as the number of years lost due to ill-
health, disability or early death. It was developed in the 1990s as a way of comparing the
overall health and life expectancy of different countries.
The DALY has become more common in the field of public health and health impact
assessment (HIA). It not only includes the potential years of life lost due to premature death,
but also includes equivalent years of ‘healthy’ life lost by virtue of being in states of poor
health or disability. In doing so, mortality and morbidity are combined into a single, common
metric.
A Daly is measured via the following formula: DALY = YLD + YLL
Years lived with Disability (YLD) = number of deaths multiplied by standard life
expectancy at age of death.
Years of Life Lost (YLL) = number of incident cases multiplied with disability weight,
multiplied by average duration of the case until remission
For example, 1 person dies at age 50 due to a disease, and the life expectancy is 80. Another
10 people suffer from the disease for 5 years, with a disability weight of 0.4.
YLD = 10 x 5 x 0.4 = 20 years
YLL = 1 death x (80-50) = 30 years
