To consider how the impact of the NHS Health Technology Assessment (HTA) Programme should be measured. To determine what models are available and their strengths and weaknesses. To assess the impact of the first 10 years of the NHS HTA programme from its inception in 1993 to June 2003 and to identify the factors associated with HTA research that are making an impact.
Main electronic databases from 1990 to June 2005. The documentation of the National Coordinating Centre for Health Technology Assessment (NCCHTA). Questionnaires to eligible researchers. Interviews with lead investigators. Case study documentation.
A literature review of research programmes was carried out, the work of the NCCHTA was reviewed, lead researchers were surveyed and 16 detailed case studies were undertaken. Each case study was written up using the payback framework. A cross-case analysis informed the analysis of factors associated with achieving payback. Each case study was scored for impact before and after the interview to assess the gain in information due to the interview. The draft write-up of each study was checked with each respondent for accuracy and changed if necessary.
The literature review identified a highly diverse literature but confirmed that the 'payback' framework pioneered by Buxton and Hanney was the most widely used and most appropriate model available. The review also confirmed that impact on knowledge generation was more easily quantified than that on policy, behaviour or especially health gain. The review of the included studies indicated a higher level of impact on policy than is often assumed to occur. The survey showed that data pertinent to payback exist and can be collected. The completed questionnaires showed that the HTA Programme had considerable impact in terms of publications, dissemination, policy and behaviour. It also showed, as expected, that different parts of the Programme had different impacts. The Technology Assessment Reports (TARs) for the National Institute for Health and Clinical Excellence (NICE) had the clearest impact on policy in the form of NICE guidance. Mean publications per project were 2.93 (1.98 excluding the monographs), above the level reported for other programmes. The case studies revealed the large diversity in the levels and forms of impacts and the ways in which they arise. All the NICE TARs and more than half of the other case studies had some impact on policy making at the national level whether through NICE, the National Screening Committee, the National Service Frameworks, professional bodies or the Department of Health. This underlines the importance of having a customer or 'receptor' body. A few case studies had very considerable impact in terms of knowledge production and in informing national and international policies. In some of these the principal investigator had prior expertise and/or a research record in the topic. The case studies confirmed the questionnaire responses but also showed how some projects led to further research.
This study concluded that the HTA Programme has had considerable impact in terms of knowledge generation and perceived impact on policy and to some extent on practice. This high impact may have resulted partly from the HTA Programme's objectives, in that topics tend to be of relevance to the NHS and have policy customers. The required use of scientific methods, notably systematic reviews and trials, coupled with strict peer reviewing, may have helped projects publish in high-quality peer-reviewed journals. Further research should cover more detailed, comprehensive case studies, as well as enhancement of the 'payback framework'. A project that collated health research impact studies in an ongoing manner and analysed them in a consistent fashion would also be valuable.