F. Collecting Cost Data in Clinical Studies.

The validity of a cost-related study depends on the sources of the data for costs and outcomes. Increased attention is being given to collection of cost data in more rigorous, prospective studies. The closer integration of economic and clinical studies raises important methodological issues. In order to promote more informed resource allocation for new technologies, it would be desirable to generate reliable cost and outcomes data during the early part of a technology's lifecycle, such as during RCTs required for seeking regulatory approval for marketing. Although an RCT would be expected to yield the most reliable data concerning efficacy of an intervention, the care given in an RCT and the costs of providing it may be atypical compared to more general settings. For example, RCTs may involve more extensive and frequent laboratory tests and other patient monitoring, and may occur more often in academic medical centers whose costs tend to be higher than in community health care institutions. Other aspects of trial design, sample size, choice of outcome measures, identification and tabulation of costs, burden on investigators of data collection and related matters affect the usefulness of clinical trial data for meaningful economic studies (Briggs 2003; Drummond 2005; Graves 2002; Poe 1995). The prevalence of multinational clinical trials of drugs and other technologies can complicate estimating country-specific treatment effects and cost-effectiveness, given differences in epidemiological factors, health care delivery models, resource use, and other factors (Willke 1998).