This document defines quality of life and discusses how it is measured. It contains the following key points: 1) Quality of life refers to an individual's well-being and includes physical, mental, social, and environmental factors. It represents how satisfied they are with their level of functioning in life. 2) Components of quality of life include physical health, psychological state, social relationships, environment, and spirituality. 3) Quality of life is assessed using valid, reliable questionnaires to evaluate things like burden of disease, impact of health policies, and patient outcomes after treatment. Common measures are quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs).

1. Dr. Dalia El-Shafei
Assist.Prof., Community Medicine Department, Zagazig University
http://www.slideshare.net/daliaelshafei

2. LEARNING OBJECTIVES:
1) Define quality of life.
2) Identify component of quality of life.
3) Understand and calculate measures of quality of life.

3. DEFINITION OF QOL
WHO : “an individual’s perception of their position in life in the context of the
cultural and value systems in which they live and in relation to their goals,
expectations, standards and concerns”.
The degree of well being, satisfaction and standardized living.
Afeeling, function and future of happiness, health and hope. With increase life
expectancy all over the world, the aim of health services is to make these added life
years of good quality.

4. COMPONENT OF QUALITY OF LIFE
• Energy & Mobility /Activities of daily living / Work
capacity
Physical Health
• Feelings, fear, depression / Self-esteem / Thinking,
learning, memory and concentration.
Psychological
• Religion/ Personal internal power
Spirituality
• Personal relationships / Social support / Role in the
family, profession and social groups of friends& relatives
Social Relations
• Physical, chemical & biological (pollution, noise, traffic,
and climate) / Transport/ home environment
Environment

5. ASSESSMENT OF QUALITY OF LIFE
Questionnaire, tests and /or instruments which must be:
Valid
Accurate
Adequate
Reliable

6. IMPORTANCE OF ASSESSMENT OF HEALTH RELATED
QOL (SCOPE OF APPLICATION)
Assess effect of community medicine programs after health policy
changes.
Measuring the burden of disease for estimating the degree of
morbidity & mortality (economic evaluation assist decision makers).
Assess patient satisfaction after clinical treatment.
Assess quality of life of handicapped.

7. INSTRUMENTS FOR ASSESSMENT OF HEALTH
RELATED QUALITY OF LIFE
Quality
adjusted life
years (QALYs)
Disability
adjusted life
years (DALYs)

8. QUALITY ADJUSTED LIFE YEARS (QALYS)
Any year lived with less than optimal health = less than one
Utility: is the patient's perception (opinion) of his/her QOLalong a line starting from 0 to 1 (indifference
from death & life) (1 = the best life).
1 year in perfect health = 1year x 1 utility =1 QALY
It’s used in economic evaluation especially cost utility analysis.
Assess years lived with high quality of health without disability or premature death.

9. Example: For 2 years bed ridden (utility = 0.5)
QALY = 2 x 0.5 = 1 year

10. DISABILITY ADJUSTED LIFE YEARS (DALYS)
WHO considered DALYs as a measure of the global burden of disease.
It is the international quantitative indicator of burden of disease as it sums the
years lost (YLL) because of premature mortality and years lived with
disability (YLD) adjusted for the severity of the disability.
DALY= YLL+YLD

14. CALCULATION OFTOTALDALY FORADISEASE IN
POPULATION
YLL
• No. of deaths X years lost from expectancy
YLD
• No. of cases X disability % X average
duration of disability till cure or death.
DALY
• YLL + YLD (+ YLL after death from
disability).

15. Example for understanding “DALY” calculation:
In 16 years old adolescents: due to accident
100 deaths (consider life expectancy = 60 years)
70 with disability divided into:
60 with disability 25% for 4 years till cure
10 with disability 30% for 3 years then died
YLL= No. of deaths x years lost from expectancy =100 x (60-16)= 4400 years
YLD= No. of cases x disability percent x average duration of disability till
cure or death = (60 x 25/100 x 4 = 60 years) + (10 x 30/100 x 3 = 9 years)
DALY = YLL + YLD
DALY = 4400+60+ 9= 4469 years
(+ YLL after death from disability = 10 x (60-19) = 410 years)
DALY =4400+60+ 9+410= 4879 years

16. RELATION BETWEEN QALY & DALY
QAL
Y assess years
lived with high quality.
DAL
Y assess years lost
of healthy life.
They are completing
each other

19. A man live for 50 years with blindness (since birth) &
utility of blindness = 0.45. Considering life expectancy =80
years, calculate QALY& DALY.
QAL
Y = years x utility = 50 x 0.45 = 22.5 years
DAL
Y = YLL+YLD
YLL = years lost from expectancy = 80 – 50 = 30 years
YLD = disability (1- utility) x years = (1- 0.45) x 50 = 0.55 x
50 = 27.5 years
DAL
Y = 30 + 27.5 = 57.5 years
DAL
Y + QALY = 57.5 +22.5= 80 years