Abstracts 431

administration trials and dose-ranging trials. We found that most protocols can be uniquely and adequately described by our eight-variable vector (DESI), associated with a nine-column matrix and a row for each decision rule (RULE).

DESI: (no. of administrations per subject, no. of decision rules, no. of outcomes, the response variable for expected effects, the response variable for adverse effects, the starting dose, the type of dose increment i.e., constant or variable, the total no. of administrations). Each decision rule is defined by RULE by: the number of subjects per administration, how the outcomes from the previous administrations are considered (3 variables), the divergent/convergent nature of the rule, the no. of possible decisions, the group/subject specificity, the total number of administrations per decision rule. Using this approach, a protocol can be summarized in the form of two tables.

P73 CONTINUING REVIEW OF TRIALS BY LOCAL ETHICS BOARDS: A REMINDER SYSTEM FOR

KEEPING PARTICIPATING CENTRES ON TRACK

Nancy Paul, Nancy Walnman, Elizabeth Elsenhauer, Lam Pho, Beverly Koskl, and Brenda Pleters Queen’s University Kingston, Canada

Institutional research ethics boards (REBs) are responsible for evaluating the relative risks and benefits of research studies to the human subjects involved. In many countries, REBs are expected to continue to evaluate the risks and benefits on a regular basis: e.g., American federal regulations require review “at intervals appropriate to the degree of risk, but not less than once per year.” The Medical Research Council of Canada (MRC) strongly recommends that researchers provide an annual update on the status of any project for which the REB has given approval.

The NCIC CTG coordinates large multi-centre clinical trials in cancer therapy and supportive care, in Canada and internationally. When it collaborates with U.S. cancer cooperative groups, the NCI U.S., or pharmaceutical companies following U.S. regulations, the NCIC CTG follows American federal law and insists that the trials be reviewed annually by REBs of all participating centres while they are accruing patients. Further, in accordance with MRC Guidelines, NCIC CTG is moving toward a policy of requiring annual review of its other trials as well.

To facilitate the record-keeping involved of maintaining most recent approval dates of all active studies by all participating centres, a database was established which can be accessed by trial or by centre. This database is critically useful for central office staff for monitoring purposes, and is as well invaluable for providing reminders lists for institutions of upcoming review requirements. Dates of last data report and protocol amendment are included on the list for each trial due for review, as this information is necessary for the REB.

P74 IMPACT OF A RANDOMIZED TRIAL ON TRANSFUSION PRACTICE

IN ORTHOPEDIC SURGERY

Lenore Dlckson, Nancy Heddle, Tlm Brox, and Mark Levlne McMaster University

Ontario, Canada

A randomized clinical trial was conducted to evaluate the efficacy of an autologous blood drainage rein- fusion device (Solcotrans) to reduce the amount of homologous blood required in patients having elective knee arthroplasty surgery. During the trial strict guidelines for erythrocyte transfusion based on daily hemo- globin were enforced.

Erythrocyte transfusion was compared between 27 consecutive knee surgery patients before trial com- mencement, 41 control patients on the trial, and 28 consecutive knee surgery patients following the trial.

Mean (SD) erythrocyte use was 2.15 (1.46), 1.2 (1 .O), and 1.75 (1.32) units, respectively. The comparison of units transfused before trial commencement and during the trial was highly significant (P=O.O02) while the comparison of on trial results and post-trial results was also significant (P = 0.05). In addition, the proportion of patients who received erylhrocyte transfusions was compared over the three phases of data collection. The percentages of patients who received homologous blood were 88.9, 67.5 and 82.1, respectively. In summary, a higher rate of homologous blood use was observed pre- and post-study periods when the transfusion guidelines were not in effect. Thus the conduct of this randomized trial had a direct but only transient impact on clinical practice.