Estimating the marginal value of 'better' research output: 'designed' versus 'routine' data in randomised controlled trials

We recently completed a study which demonstrated that the costs of health technology assessment (HTA) by randomised controlled trial (RCT) can be reduced by substituting routine datasets for data designed and collected specifically for a trial. This cost reduction, however, had the effect of reducing the quality of the research output. In the present study we attempted to tease out the values attached to the 'better' information provided by designed data RCTs using a mock grants committee. Two valuation techniques, implied values and willingness to pay, were used. Ex ante valuations were determined by comparing alternative research proposals - a more costly version using designed data and a cheaper version using routine data. Ex post valuations were determined by comparing results of both versions. The exercise was performed on four exemplar studies. Overall, the committee expressed a general lack of trust towards routine data both ex ante and ex post and placed high values on the better information from the designed data studies - particularly information on preferences. This suggests that currently available routine datasets are not perceived to be able to provide efficient alternatives to designed data for RCTs. Copyright © 2003 John Wiley & Sons, Ltd.