Redefining Health Technology Assessment: A Comment on "The New Definition of Health Technology Assessment: A Milestone in International Collaboration".

A new definition of health technology assessment (HTA), developed by an International Joint Task Group claims to be a "milestone," "an historic achievement," and "a cornerstone reference"-claims that we think to be unjustified. We too favor clear definitions, especially when confusion abounds. However, the Task Group seems to have developed a definition without the help of usual conventions regarding definitions and, in our view, through an ill-described process. A definition ought to differentiate the entity defined from other entities. This one fails to do so. It states traits that are true of HTA (e.g., that is interdisciplinary) but HTA is not alone in this. There are other concerns: examples of HTA's use are embodied in the definition, precluding other uses; the adjectives used, although generally true of HTA, are not differentiating features; and attributing to HTA specific purposes, thereby excluding other purposes. We have sympathy for these purposes but cannot consider them HTA's purposes or even, its purpose. A newcomer to HTA, on reading this definition, will have no idea of HTA's true potential. These numerous failings, we feel, send all the wrong signals, and could ultimately weaken, rather than strengthen perceptions of HTA's legitimacy and objectivity. The production of a good definition remains, therefore, a work in progress.