Searching for a threshold, not setting one: the role of the National Institute for Health and Clinical Excellence.

There has been much speculation about whether the National Institute for Health and Clinical Excellence (NICE) has, or ought to have, a 'threshold' figure for the cost of an additional quality-adjusted life-year above which a technology will not be recommended for use. We argue that it is not constitutionally appropriate for NICE to set such a threshold, which is properly the business of parliament. Instead, the task for NICE is as a 'threshold-searcher' - to seek to identify an optimal threshold incremental cost-effectiveness ratio, at the ruling rate of expenditure, that is consistent with the aim of the health service to maximize population health. This will involve the identification of technologies currently made available by the National Health Service that have incremental cost-effectiveness ratios above the threshold, and alternative uses for those resources in the shape of technologies not currently provided that fall below the threshold.