Download NICE`s approach to assessing public health interventions

UNDERSTANDING QUALITY ADJUSTED LIFE YEARS
The quality-adjusted life year or quality-adjusted life-year (QALY) 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 for money of medical
interventions. One QALY equates to one year in perfect health.
The QALY is a measure of the value of health outcomes. Since health is a function
of length of life and quality of life, the QALY was developed as an attempt to
combine the value of these attributes into a single index number. The basic idea
underlying the QALY is simple: it assumes that a year of life lived in perfect health is
worth 1 QALY (1 Year of Life × 1 Utility value = 1 QALY) and that a year of life lived
in a state of less than this perfect health is worth less than 1. In order to determine
the exact QALY value, it is sufficient to multiply the utility value associated with a
given state of health by the years lived in that state. QALYs are therefore expressed
in terms of "years lived in perfect health": half a year lived in perfect health is
equivalent to 0.5 QALYs (0.5 years × 1 Utility), the same as 1 year of life lived in a
situation with utility 0.5 (e.g. bedridden) (1 year × 0.5 Utility). QALYs can then be
incorporated with medical costs to arrive at a final common denominator of
cost/QALY.
NICE's approach to assessing public health interventions
Cost–utility analysis
Up to 2012, based on Methods for the development of NICE public health guidance
(2nd edition), cost–utility analysis was NICE's main method of determining the cost
effectiveness of public health interventions. This considers someone's quality of life
and the length of life they will gain as a result of an intervention. The health benefits
are expressed as quality-adjusted life years (QALYs).
Generally, NICE consider that interventions costing the NHS less than £20,000 per
QALY gained are cost effective. Those costing between £20,000 and £30,000 per
QALY gained may also be deemed cost effective, if certain conditions are satisfied.
Cost–consequences and cost–benefit analyses
Drawing on experience gained from producing public health guidance, the latest (3rd
edition) of 'Methods for the development of NICE public health guidance', published
in 2012, places more emphasis on cost–consequences and cost–benefit analyses
when assessing public health interventions.
This dual approach aims to ensure all relevant benefits (health, non-health and
community benefits) are taken into account. The idea is to help local authorities (and
other organisations interested in improving people's health) better judge whether or
not a public health intervention represents value for money
Cost–utility analysis is also used, when needed, to make comparisons with previous
economic analyses, as well as to compare treatment and prevention programmes.
EXAMPLE
NICE uses a unit of measurement called the "Qaly" - the "quality-adjusted life year".
It gauges drug effectiveness in terms of how much it would cost to give you a year of
healthy life.
So a drug that cost £50,000 and gave patients an extra six months of life in good
health would cost £100,000 for a full Qaly. If the same drug at the same price was
much better, and led to two years of life in good health, it would cost about £25,000
per Qaly.
Patients are also deemed to "gain" Qalys for periods of better health. That means
that an intervention that does not prolong life, but does improve it, could be justified
for funding. That's what the "quality-adjusted" bit in "Qaly" means.