Plain English Summary

The problem 

The National Institute for Health and Care Excellence (NICE) makes informed decisions on what can be funded by the National Health System (NHS).  NICE considers the costs of the different treatments and their benefits and this is referred to as health technology assessment. Previous studies have found that members of the public prefer to treat those with more severe conditions compared with those with less severe conditions. Severe conditions are those that impact most on either the quality of life or the number of years one is expected to live or on both. In other words, there is evidence to suggest that NICE should give additional weights for treatments in most severe conditions.  In response to this preference, NICE introduced what it calls a “severity modifier” which is this additional weight that should be placed on most severe conditions. NICE suggested a method for this to happen and has also suggested an estimate of how  much this extra weight should be. However NICE has also committed to commission research to find out whether the methods they suggest, and the magnitude of the weight reflect the views of the UK public. 

What is the purpose of this research? 

The aim of this research was to make some broad recommendations to NICE that it should consider when commissioning research on obtaining preferences for “severity” in health technology assessments.  

What did we do? 

First, we searched the literature for the methods that have been used to understand society’s preference and get values for the additional weight that people are willing to give for more severe conditions. We drew upon one existing systematic review and four core papers and summarised what we found in a briefing report.  Second, we conducted a workshop with 14 experts from academia, think tanks, NICE and the Department of Health and Social Care to get their views. 

What did we find? 

We identified four techniques that were most widely used to obtain weights to reflect society’s preferences. These techniques are called Discrete Choice Experiment (DCE), person trade-off (PTO), benefit-trade-off (BTO) and Social Willingness to Pay (SWTP).  Among these techniques, PTO is the most commonly used. Technical details of each of the techniques were appraised. The experts agreed that DCE, PTO and BTO were the most promising techniques, and they were unsure about SWTP as a technique. Experts discussed that NICE should draw up a list of criteria that will make a “good” study and this should include: a clear way to ensure the data collected is of high quality, the representativeness of the sample, how best to collect the data, how to ensure that the tasks respondents in a study have to undertake are made easy to comprehend. The experts also stated that any quantitative study should be complemented with qualitative interviews to ensure that the results (the weights derived) reflect the preferences of people.  Experts were not in favour of NICE specifying a technique when commissioning research.