Clinical trials economic evaluation

Only two randomized, controlled trials have been completed, and neither provides anything like compelling data (Table 2.6). Chouinard and Albright (1997) conducted a unique evaluation of a subset of patients from a previously conducted clinical trial. Subjects were categorized and profiled at baseline and end point according to clinical severity, and a group of psychiatric nurses were asked to rate various aspects of likely outcome and quality of life to each profile (mild, moderate or severe symptoms). Health state utilities were then calculated risperidone was found to provide more than double the number of quality-adjusted life years compared with haloperidol. Csernansky and Okamoto (1999) conducted a rather more conventional trial, but included no economic analyses. However, they did find that the use of risperidone substantially reduced relapse rates compared with haloperidol—an outcome likely to have a positive impact on cost-effectiveness. 

Davies EM (1998). Economic evaluation in clinical trials. Appl Clin Trials , 62-70. 

In recent years in some developed countries, the requisite of presenting economic evaluation (that is, pharmacoeconomic) studies of new dmgs has been introduced alongside the existing one of clinical trials. These studies have to provide proof of their efficiency (or cost-effectiveness) as a condition for the public financing of the new product. These studies improve information and market transparency and may help to make competition keener, but like the earlier requirements regarding effectiveness and safety, they constitute an additional cost factor and as such raise further barriers to entry. 

Section 1 of the guidelines establishes the context of the submission. It asks for a description of the drug, its use on the PBS and the therapies that wiU be co-administered or substituted. Section 2 asks for the best available evidence on the clinical performance of the drug, including the scientific and statistical rigour of randomised trials, and a preliminary economic evaluation based on evidence from the randomised trials. Section 3 describes when extrapolation beyond the preliminary economic evaluation maybe made and how adjustments can be made in a modelled economic evaluation. Section 4 requests a financial analysis from the perspective of the PBS and government health budgets. 

More generally, the presence or absence of good clinical data imposes limits on the economic evaluations that can be conducted. It is usually easier to undertake economic evaluations of drug therapies, where there are usually some reasonable clinical data, as compared with medical devices or procedures. However, even for drugs, the data from standard Phase 3 clinical trials are far from ideal. These trials are usually conducted under conditions that are atypical of normal practice. In addition, they are often of short duration and often fail to compare the most relevant alternatives for economic evaluation. This means that decision-analytic modeling is usually required as a supplement to, or alternative to, economic analysis alongside trials. 

At the time of a reimbursement decision, it is highly unlikely that there will be head-to-head clinical trials of the therapies concerned. Such trials are costly and time consuming to undertake, or it is not possible to undertake a trial comparing two investigational therapies. Whatever the reason for the lack of head-to-head studies, an economic evaluation seeking to provide relevant information to a reimbursement agency must incorporate an estimate of treatment effect that is based on indirecf comparisons. 

Third, economic data may have been collected together with a multinational clinical trial, and economic evaluations are required for all the countries enrolling patients in the trial. Here the analyst has a number of options for analyzing the resource-use data. 

Ghck H, Wihke R, Polsky D, Liana T, Alves WM, Kasseh N, Schulman KA. Economic analysis of tirilazad mesylate for aneurysmal subarachnoid hemorrhage economic evaluation of a phase IB clinical trial in Eu-... 

Reed SD, Anstrom KJ, Bakhai A, Briggs AH, Califf RM, Cohen DJ et al. Conducting economic evaluations alongside multinational clinical trials toward a research consensus. Am Heart J 2005 149 434-43. 

In economic evaluations, there is a need to make assumptions about the variables in the analysis. For instance, assumptions that are made commonly include the incidence of adverse effects, the drug s efficacy (in clinical trials) and effectiveness (use in actual practice), and the costs of drugs or other direct medical costs. It is important to keep in mind that assumptions are simply predictions about what a researcher thinks might happen as a result of a program or intervention. To account for the variety of outcomes that may arise in any intervention, researchers should use a technique known as... 

Hughes, D.A. Walley, T. Economic evaluations during early (phase II) drug development a role for clinical trial simulations Pharmacogenomics 2001, 19 (11), 1069-... 

Feeny DH, Torrance GW, Labelle R. Integrating economic evaluations and quality of life assessments. In Spilker B, ed. Quality of Life and Pharmacoeconomics in Clinical Trials, 2d ed. Philadelphia, Lippincott-Raven, 1996 85-95. 

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