Evaluation of a decision aid for transfusion alternatives for patients before open heart surgery: Assessment of the perceptions of small risks

Abstract

Background. Patients facing open-heart surgery have the choice of donating their own blood prior to surgery for their later use (pre-operative autologous donation), or accepting volunteer-donated (allogeneic) blood. A decision aid, consisting of an audiotape and a booklet, was developed to assist patients to make this decision. It defined "blood transfusion", and clarified its role in heart surgery. Non-transfusion alternatives were listed. It described the two transfusion options, their risks and benefits and gave probabilities of complications. A summary chart allowed the patients to compare the pros and cons of each method. Objectives. (1) To evaluate the decision aid's effect on specific outcomes. (2) To evaluate the decision aid's acceptability to heart surgery patients. (3) To assess the importance of others' opinions in making the decision to pre-donate blood before heart surgery. Design. Before-after trial. Setting. Outpatient surgery clinics, Ottawa Heart Institute, University of Ottawa. Participants. A consecutive series of 70 patients who were to have open-heart surgery in the future. Patents were English-speaking and were potential candidates for autologous blood donation. Measurements. Knowledge, values (importance ratings), preference for transfusion method, decisional conflict and risk perception were measured before and after the decision aid was used. Decision aid acceptability and importance of opinions of others were measured after the decision aid.