Quality of life assessment Flashcards
Define quality of life
a conscious cognitive judgement of satisfaction with one’s life
Define health related quality of life
a multidimensional construct measuring the physical, social and emotional aspects that are relevant and important to a patient’s wellbeing
What is a QALY?
quality adjusted life years
1 QALY = 1 year in full health
years spent in less than full health are quality-adjusted
How are QALYs calculated?
(number of years in full health x 1) + (number of years in less than full health x utility score)
utility score = scale from 0-1 with 1 being perfect health and 0 being dead
Describe Time Trade off
asks respondents to trade off life expectancy for improved quality of life
basic idea is that the worse you consider a health state to be, the more life expectancy you would be willing to sacrifice to avoid it
What are some criticisms of QALYs
conceptual/theoretical
problems of utility measurement - how health states are valued
problems of generic classification system - how health states are described
What is a DALY?
disability-adjusted life years
How is a DALY calculated?
DALY = years of life lost (YLL) + years of life lost due to disability (YLD)
What factors are incorporated in DALYs?
duration of time lost due to a death at each age or age bands
disability weights associated with different non-fatal conditions
age weights relative importance of healthy life at different ages
time preference values health gains today compared to the value attached to health gains in the future
Criticisms of DALYs
uses maximum standardised life expectancy (eg. Japan) inapplicable to all countries (especially developing countries)
age weighting and discounting gives preference to young adults
quality of life weights currently based on ‘expert opinion’
What is the difference in how DALYs and QALYs are used?
DALYs are used to measure burden of disease - used by WHO
QALYs are used to measure health gain in economic evaluations - used by NICE
