Two papers published on bmj.com today raise serious concerns over the methods used to put a value on the benefits of different treatments in order to set healthcare priorities.
Most rationing decisions are based on what people think they might feel rather than the experiences of people with real diseases. Both papers show that these two approaches provide very different results.
To make resource allocation decisions, health economists and policy makers use utility values for different conditions or health states. This approach assigns a value between 0 (for death) and 1 (for full health) to each condition or health state and then multiplies that value by how long the state lasts.
Measuring such values is not straightforward and can be controversial but, broadly speaking, there are two groups of methods. The first is to obtain the values directly (usually from patients), and the second, which is used more often, obtains them indirectly by using a quality of life questionnaire, the results of which are converted to utilities using "weights" (tariffs) obtained from the general public.
In the first paper, researchers at the Universities of Birmingham and Cardiff analysed 32 studies, involving 4,688 respondents, which compared direct and indirect methods for a wide range of diseases.
Each study was classified according to whether the respondents were "current patients" (with direct experience of a certain condition) or "hypothetical patients" (asked to imagine the experience of the condition).
They found that indirect methods produce consistently lower utilities (worse recorded health) than the direct group of methods. As such, they warn that any reliance on indirect methods will result in fewer resources being allocated to life saving treatments than if direct methods were used.
Because direct and indirect methods can lead to such noticeable differences in elicited utilities, the authors conclude that priority setting institutions should avoid using a mixture of methods for different decisions.
In the second paper, Paul Dolan and colleagues from Imperial College London look at how the National Institute for Health and Clinical Excellence (NICE) values health.
NICE values health in terms of gains in quality adjusted life years (QALYs). To measure these values, NICE advocates methods that ask members of the general public to think about how many years of life they would be willing to trade to avoid different states of health.
But the authors argue that these hypothetical preferences often bear little relation to the real experiences of those who have the condition.
They propose an alternative approach - measuring subjective well-being - to help direct resources to treatments in proportion to the real suffering they alleviate.
Measuring subjective well-being in this way involves asking those directly affected by a condition (parents, carers, relatives etc) to rate their daily moods and overall life satisfaction. This information is then analysed with other factors known to be linked with subjective well-being, such as income and marital status.
Most of us recognise that NICE has to take account of quality of life and length of life gains when judging the relative cost effectiveness of different interventions, say the authors. Subjective well-being provides us with a means of valuing the real reduction in suffering that health technologies bring in the wider context and experience of people's lives.