A42 Economic evaluation alongside clinical trials: A problem or a solution?

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Abstracts

Clinical evaluation focuses on a primary outcome used for efficacy decisions and includes several secondary outcomes as well as safety parameters. Sample size is adjusted according to the expected difference and variance of the estimate for the primary outcome. Economic evaluation is summarized in a single variable in its numerator (Cost) whose variance has to be estimated. Estimation of this variance must include variation due to clinical parameters and uncertainty associated with the cost quantification of each unit cost. We recently conducted a double blinded placebocontrolled randomized clinical trial (the PARI-IS Study) to examine the effect of an immunostimulating agent in the prevention of acute respiratory infections (ARIs). 381 patients living in Montreal were randomized into two arms. A third arm consisting of 191 patients was appended to the RCT and included in the economic evaluation. Modeling involving the different sources of variation and sensitivity analyses on uncertainly have been developed. Experience from the PARI-IS study shows the instability of economic results when involving multiple outcomes and difficulties in interpreting these results due to lack of statistical power. A42 ECONOMIC EVALUATION ALONGSIDE CLINICAL TRIALS: A PROBLEM OR A SOLUTION? Seema Haider*, And&Pierre Contandriopoulos*, Thierry Ducrute** and Jean-Paul Collett** Wniversitt!de Montrkal **Jewish General Hospital McGill Universily Montreal, Canada Economic evaluation studies alongside Phase III randomized clinical trials (RCT) are gaining popularity as health care cost escalate. Data collected within these Phase III RCTs are limited because of the trial environment which is artificial when compared to the world where the medication will be used. One solution to this problem is the addition of a third arm, the “usual care” arm, to the trial. Patients in this third arm are treated as if they are not part of the trial so that influences arising from protocol restrictions and participation in a clinical trial are eliminated. Resource utilization and clinical data from thii arm reflect that detected in usual care in the “real world”. This data is compared to that collected from patients in the RCT. We recently completed a Phase III RCT with a “usual care” arm appended and found that there are four major technical and operationalixational challenges associated with performing economic evaluations based on such a study. These are: (1) validity of the comparison of the three groups; (2) the problem of patient recruitment for the three arms; (3) ethical considerations; and (4) the high costs of collecting, processing and analyzing resource utilization data. Nevertheless, the addition of a usual care arm is one way to approach effectiveness data use and a step beyond efficacy data use in economic evaluations alongside Phase III RCTs.