Published: 26/05/2005, Volume II5, No. 5957 Page 20 21
Quality-adjusted life years have become the bread and butter of health economic analysis.
But do their make-up and use discriminate against older people and those with long-term conditions? Nick Bosanquet and Sir Michael Rawlins beg to differ
FOR NICK BOSANQUET
Nick Bosanquet is professor of health policy at Imperial College London. He has been special adviser on public expenditure to the Commons health select committee since 2000. He is also a non-executive director of a London primary care trust.
AGAINST SIR MICHAEL RAWLINS
Sir Michael Rawlins is chair of the National Institute for Health and Clinical Excellence. He has been professor of clinical pharmacology at Newcastle University since 1973 and is chair of the Advisory Council on the Misuse of Drugs.
Nick Bosanquet: The quality-adjusted life year has become an established feature of health economic analysis.
The QALY is seen as objective, rational, mathematical and externally valid. It is becoming almost impossible to make a case for the introduction of a new approach to treatment without including costper-QALY data.
The aspiration for a universal healthcare measure is understandable and even admirable.
But the worry is that with something as amorphous as human health, a one-size-fits-all approach will push square pegs into round holes.
QALYs have twin foundations - they can judge the quality of life that a drug or treatment will provide and they can predict how long these benefits will last. Put another way, they aim to measure quality and quantity.
However, elderly people may be especially at risk of losing their way in the QALY maze. QALYs measure life expectancy. Any treatment or drug is bound to produce a shorter benefit in an older person in terms of the years left to them to enjoy improved health.
Put at its simplest, saving the lives of younger people is always going to produce more QALYs than saving older people.
Those with chronic or mental illnesses may also be disadvantaged by the approach because qualityof-life measures largely focus on physical rather than psychological or social disability. While physical mobility, pain and disability continue to be the core measures of quality of life for QALY calculations, studies demonstrate that these are not the priority for people with mental illnesses.
Psychological well-being, personal autonomy and social interaction have been highlighted as more important than traditional measures of quality of life.
In dementia, for instance, there are no reliable, well-validated measures of quality of life. The National Institute for Health and Clinical Excellence acknowledges this - yet still insists on constructing QALYs around dementia treatments. NICE then says these QALY costs are too high. It is like building a house without foundations and then turning round and condemning it as unsafe.
Another aspect of healthcare that is lost from QALY calculations is the impact of treatment on carers.
A successful intervention can significantly improve the quality of life of carers, and reduce care costs.
But if these 'third party' benefits are not included in calculations, certain interventions will be systematically undervalued.
QALYs are not a set of scales or a tape measure that will impartially weigh or measure whatever is put in front of them. They are a judging panel. It depends entirely on how the rules are set as to who wins the prize. The same rules to judge a fine wine are not applied to judge novels.
In seeking to be a universal healthcare measure the QALY places elderly people and those with longterm mental illness at a terrible disadvantage. A more accurate, and fairer, measure than the QALY is needed in these cases.
Sir Michael Rawlins:In responding to Nick's comments, I hope readers will understand that I cannot comment on the current appraisal of Alzheimer's drugs: NICE has yet to finalise its guidance and it would be inappropriate for me to second-guess the conclusions of our appraisal committee.
However, I can say that Nick seems to be a little confused about QALYs and how they are used by NICE.
QALYs measure health-related aspects of quality of life. These encompass physical mobility, ability to self-care, ability to carry out activities of daily living, absence of pain or discomfort, and absence of anxiety or depression. They are underpinned by an extensive body of empirical evidence and have been shown to be appropriate for those with a wide range of conditions, including mental health.
QALYs do not, of themselves, provide a measure of costeffectiveness. To inform an economic judgment QALYs are expressed as a ratio - the incremental cost per QALY.
Costs can include health service costs, carer costs and wider societal costs. NICE is legally obliged by its statutory instruments, however, to limit its considerations of costs to those falling on the health service.
When both the costs and benefits continue year on year - as (for example) with pharmacological treatments for chronic diseases - the cost per QALY is age-independent.
Nick is therefore incorrect in claiming that QALYs are inherently ageist. In many instances estimates of the cost per QALY are advantageous to older people. This is the case, for example, in the secondary prevention of osteoporosis where the cost per QALY falls with age.
It happens because the health gain, for products that prevent bone loss, is greater in older people.
Recent NICE guidance reflects this.
Similar relationships hold for the use of neuramidase inhibitors in preventing and treating influenza.
Estimates of a technology's incremental cost per QALY, however, is not the sole basis on which NICE decides its guidance. It only 'informs' decisions. NICE's advisory bodies do not slavishly follow some arbitrary QALY threshold. To do otherwise would imply that efficiency had an absolute priority over equity.
In deciding whether a product's incremental cost per QALY represents an appropriate use of NHS resources, NICE's advisory bodies consider the degree of uncertainty surrounding its estimate, the particular features of the condition and its associated patient population, the innovative nature of the technology, wider societal costs and previous appraisals.
Nick Bosanquet: The value assigned to a treatment varies most depending on how long it might extend a patient's life. The use of costly treatments are typically only justified when several years of life can be gained. Such gains are less likely with elderly patients.
In practice it is survival which counts, and the longer the survival the higher the QALY gain. Younger people have an advantage, as effective treatment for lifehreatening disease is likely to bring a surge in life expectancy.
The disability dimension of QALYs is most important when there is a move from near full health to a high level of disability - again a change which is most likely in younger people.
The measure is not particularly sensitive to the kind of aims in health and social functioning which may be crucial to elderly people. An enhanced capability for normal living does not show up in terms of any significant QALY gain - but it may have a very big effects in contributing to dignity, privacy and control in the last phase of life.
The gain made for elderly people needs to be evaluated in terms of their own perspective - and that of carers - and realistic prospects. Using one measure across the whole life span is bound to mean that older people's special interests get pushed aside.
If, for example, a therapy allowed people to stay in their own homes for several months this would not show a high QALY value even though it might add greatly to their well-being, as well as saving the NHS considerable costs.
Sir Michael Rawlins: Nick still hasn't got it. Let me try an example: if a drug produces a QALY gain of 0.5, and costs£10,000 per year, the incremental cost-effectiveness ratio will be£20,000 per QALY and it will be the same for those aged three or 83. Age only comes into the reckoning if the QALY gain itself rises or falls with age.
This is the case with drugs for the secondary treatment of osteoporosis where, for example with alendronate, the incremental costeffectiveness ratio (ICER) falls from£32,936 per QALY at age 50 to£12,191 per QALY at age 70. Of course, savings from delayed admission to a nursing home would count substantially as a cost saver in the ICER calculation.
Elderly people would only be disadvantaged in the case of a hugely expensive, curative procedure whose benefits were lifelong. A child aged three would then be likely to enjoy more than 70 years of benefit compared to the additional five years that an 80-year-old would enjoy. I cannot, though, think of an example of a single 'one off' procedure costing£150,000.
NICE does not differentially value life. We are currently consulting on social value judgements that should inform the decisions made by the independent committees that advise us. Visit www. nice. org. uk. for the consultation document. The consultation closes on 30 June. .