Moderator – Dr. Abhishek V. Raut

Plan of the presentation

Various indicators Of Disability

What are DALYs?

What can they be used for?

How are DALYs constructed and calculated?

Relation between QALY and DALY.

Problems with DALYs approach

What is Global Burden of Disease Study ?

Summary

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Indicators Of Disability In 1940, Dempsey's concept of using “Years Of Life Lost” was

used as a metric for assessing the health burden associated with deaths occurring prior to an ‘ideal’ life span of 65 years.

“Life Tables” approach was a subsequent measure incorporating non-fatal health outcomes using a life-table approach which quantified time lived with disease or injury lost according to severity of disability , pain or distress.

“Sullivan’s index” is computed by subtracting from life expectancy, the probable duration of bed disability and inability to perform major activities, is one of the advanced indicators.

Concept of DALY was first presented in the “World Development Report; 1993” by the World Bank and gained wider attention and interest.

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What are DALYs? DALYs = Disability Adjusted Life Years is a measure of

disease on the defined population and the effectiveness

of interventions.

A common measurement unit for morbidity and

mortality

Facilitates comparisons of all types of health states and

outcomes

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Possible uses of DALYsDALYs can be used in three interrelated areas:

For epidemiological surveillance of the total disease burden

(number of DALYs)

To measure cost- effectiveness of interventions (cost per

avoided DALY)

To decide what should be included in a country’s ‘core services’ (the package of essential health care services).

The concept of DALYs thus provide information for

policy makers concerned with international health, the health

of developing countries, and national priority setting.

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How are DALYs constructed?

One DALY can be thought of as one lost year of "healthy" life.

The sum of these DALYs across the population, can be thought

of as a measurement of the gap between current health status and

an ideal health situation where the entire population lives to an

advanced age, free of disease and disability.

A DALY is a health outcome that measures-

◦ the Years of Life Lost (YLL) due to premature mortality

in the population and

◦ the Years Lost due to Disability (YLD) for incident cases

of the health condition

◦ DALY = YLL + YLD

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How are DALYs constructed?

DALY = YLL + YLD

YLL = N * L

where:

N = number of deaths

L = standard life expectancy at age of death in years

YLD = I * DW * L

where:

I = number of incident cases

DW = disability weight

L = average duration of the case until remission or death (years)

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DALYs due to living with disability

82.5YEARS

NO

DISABILITY

Life expectancy For the normal life

Degree of disability

Normal life

Degree of disability & Quality of Life

Example; a girl aged 5 & a victim of a mine explosion causing a below-knee

amputation, and she does not die but is rehabilitated to a health state with some

loss of physical functioning. Her loss is 77.5 years adjusted by a disability weight

i. If this weight is, say, 0.3, her loss is 0.3 x 77,5 = 23.3.8

DALYs due to early death

(Red area measures DALYs. Red + white is a normal life)

NO

DISABILITY

82.5YEARS

Lifetime

lost due to

premature

mortality.

Premature death from a myocardial infarction, say at age 50. This

patient’s loss is 33.5 years.(DALY= YLL= N *L ) No adjustment is made for disability because the patient dies.

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DALYs due to disability and premature death

combined.

NO

DISABILITY

82.5YEARS

This graph shows a woman who lives with a disability, for instance deafness

from the age of 5 and dies prematurely at the age of 50.

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