Exploration of the difference in results of economic submissions to the National Institute of Clinical Excellence by manufacturers and assessment groups.

OBJECTIVES: A recent study showed that estimates of cost-effectiveness submitted to National Institute for Health and Clinical Excellence (NICE) by manufacturers had significantly lower incremental cost-effectiveness ratios (ICERs) than those submitted by university-based Assessment Groups. This study extends that analysis. METHODS: Data were abstracted from relevant NICE documentation for thirty-two of eighty-two possible appraisals. RESULTS: The results from the analysis showed that sources of the difference in ICERs appear to be the effectiveness estimates relating to the comparator technology and the cost estimates relating to the technology under evaluation. That is, manufacturers estimated lower average benefits for the comparator technology and lower costs relating to the technology under evaluation compared with estimates submitted by the Assessment Groups. CONCLUSIONS: These findings may be particularly important, given the introduction of the "Single Technology Appraisal." Considerable difficulties were encountered when undertaking this study, highlighting, above all else, the complexity of explaining why results from economic evaluations purporting to answer the same question diverge.