Allocating scarce global health resources

How do you compare the value of treatments for different conditions? Sheffield researchers have developed an algorithm to inform global healthcare decisions that takes account of people’s preferences for different aspects of health.

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The World Health Organisation states that global spending on health continually rose between 2000 and 2018, reaching £8.3 trillion or the equivalent of 10 per cent of global GDP.

But deciding which healthcare interventions to fund is a complex and often emotive question. With a limited amount of funding and unlimited demands for healthcare, health organisations around the world have to decide which interventions to prioritise and which to put on hold.

The pharmacoeconomic industry uses generic health measures to compare the overall benefit of a drug or therapy for one condition to another. However, these measures do not enable them to understand which factors are most important to the patients experiencing the condition.

“You have no way of knowing which health state a person would prefer to be in. For example, would the patient prefer more pain but have better physical functioning, or vice versa? In order to properly value a healthcare intervention, it’s important to understand the preferences of the people who might experience them” explains Jennifer Roberts, Professor of Economics at the University of Sheffield.

Jenny’s research focuses on applied economics and the interaction of health-related behaviours and labour market outcomes. Working with Emeritus Professor John Brazier, and Mark Deverill (both formerly of the School for Health and Related Research) the team developed a tool to evaluate the economic impact of health interventions based on population preferences. The tool takes into account what aspects of health were most valued by people.

The Short Form 6 Dimension (SF-6D) measure is one of only three generic tools (as opposed to those used to explore specific health conditions) in use by pharmaceutical companies and health decision-making bodies around the world.

Developing the SF-6D

The SF-6D was derived from the Short Form 36 Health Survey Questionnaire (SF-36), the most widely used measure of general health in clinical studies globally.

While the SF-36 provides a way of comparing the effectiveness of different health interventions, it does not allow for how people ‘trade’ between different dimensions of health (e.g. pain vs physical function) or between the difference in quality and length of life; in contrast, the SF-6D does allow for this.

Following funding from GlaxoSmithKline in 1999, Professor John Brazier led the development of the original SF-6D based on simplified elements of the SF-36.

By calculating the change in the quality of life arising from an intervention, the SF-6D estimates how much that intervention is worth in economic terms. This allows the benefits arising from treatments for very different conditions such as diabetes, dementia and cancer to be effectively compared.

The algorithm generates a value for health states ranging from 0 (the equivalent of being dead) to 1 (best or full health) and quantifies how much value people place on different health limitations. These values are based on their preferences for different aspects of each health state.

The tool rates health states based on factors such as physical functioning, pain, mental health and vitality. Each state has a qualitative description and the SF-6D can describe 18,000 health states in total.

This rich descriptive system means that it is sensitive to changes in health and can be applied to a wide range of physical and mental health conditions.

The SF-6D translates health improvements into quality-adjusted life years. This means that you can compare the benefits of a surgical intervention such as a hip replacement with a counselling intervention for depression, as it creates a generic baseline for improvement of health. For an effective economic evaluation of a healthcare intervention, you need to be able to rank things and state that one is better than the other. Rather than asking doctors and experts to provide assumptions about this information, our algorithm is based on data taken from the UK population.

Professor Jennifer Roberts

Professor of Economics

Informing decisions

In 2002 the original journal article was awarded the International Society for Quality of Life annual prize for the best article on quality of life research and has since been cited over 2300 times.

Globally, the tool is used by health regulatory agencies and major pharmaceutical companies including Novartis, AstraZeneca, Pfizer, and Merck through the purchase of the licence to use the algorithm to analyse their own data. It is accepted as a tool for valuing healthcare interventions in at least 20 countries around the world, including China, the US and the UK.

The SF-6D is also used widely in scientific research and can be accessed for free by researchers and charities.

The method for collecting data has been replicated in Australia, Brazil, China, Indonesia, Japan, Portugal, Singapore and Spain to enable national healthcare associations to take account of local population preferences.