Summary%20Measures%20of%20Population%20Health:%20Measuring%20the%20impact%20of%20disease,%20injuries%20and%20risk%20factors

1

• Summary Measures of Population Health Measuring
  the impactof disease, injuries and risk factors

2
Objectives

• To derive internally consistent estimates of
  incidence, prevalence, disease progression and
  mortality for over 100 disease and injury
  categories
• Communicable, maternal, perinatal and nutritional
  conditions
• Non-communicable diseases
• Injuries
• To elicit a numerical value (weight) reflecting
  the general populations relative preference for
  each disease/disability state on an interval
  scale

3
Summary Measures of Population Health (SMPH)

• Expectancy - life years lived
• Health Adjusted Life Expectancy (HALE)
• Disability Adjusted Life Expectancy (DALE)
• Disability Free Life Expectancy (DFLE)
• Gap - life years lost (compared to ideal)
• Disability Adjusted Life Year (DALY)
• Health Adjusted Life Years Lost (HALY)

4
Calculating HALYsHALY YERF YLL

• Full Health Partial Health
  Premature mortality

5
Calculating YLL

• Death Life Expectancy
• Years of life lost to premature mortality
• YLL M L
• where M number of deaths
• L remaining life expectancy

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Calculating YERFs

• Disease Death
• Years of life lived with the disease
• YERF I (1-P) D
• where I incident cases
• P preference score
• D average duration

model
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Key inputs to summary measures

• Mortality by age, sex and cause
• Epidemiological data on non-fatal health outcomes
  by age, sex and cause
• Valuations of health states

8
Top 10 Leading Causes of Death and DALYs (data
from Canada)

• Leading cause of death
• 1 Ischaemic heart disease
• 2 Stroke
• 3 Lung Cancer
• 4 COPD
• 5 Colorectal cancer
• 6 Dementia
• 7 Diabetes mellitus
• 8 Prostate Cancer
• 9 Breast Cancer
• 10 Suicide

• DALYs
• 1 Ischaemic heart disease
• 2 Stroke
• 3 COPD
• 4 Depression
• 5 Lung cancer
• 6 Dementia
• 7 Diabetes mellitus
• 8 Colorectal cancer
• 9 Asthma
• 10 Osteoarthritis

9
Burden attributable to 10 risk factors
Tobacco
Physical inactivity
High blood pressure
Alcohol harm
Alcohol benefit
Obesity
YLL
Lack of fruit/veg.
YLD
High blood cholesterol
Illicit drugs
Occupation
Unsafe sex
-4
-2
0
2
4
6
8
10
12
Attributable DALYs as a proportion of total DALYs
10
HALYTotal for top 15 cancers
11
Attribution of total HALYS for all cancers
combined to Risk Factors
Total 49
12
Part 2 Weighting of Health States

• To elicit a numerical value (preference score) on
  an interval scale reflecting the populations
  relative preference for health states
• Describe health in terms of functional status or
  capacity

13
Eliciting Health State Preferences

• Methods Tested
• Visual Analog Scale (VAS)
• Standard Gamble (SG)
• Time Trade Off (TTO)
• Person Trade Off (PTO)

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Visual Analog Scale
1
Full Health
0.75
0.5
Poor Health
0.25
Death
0
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Standard Gamble
You have a lifelong stationary impaired health
state and are given a choice. Do you take a
hypothetical procedure that will

• Give instantaneous and lasting improvement to
  full health with probability p

• Give immediate death with probability 1-p

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Time Trade-Off

• Years of healthy life you would give up to avoid
  living in a state of poor health

17
Person Trade Off (PTO)

• N? 1,000 individuals in a disabling health
  state

• 1,000 healthy individuals