J Chron Dis Vol. 40, No. 8, pp. 81 l-818, 1987 Printed in Great Britain. All rights reserved 0021-9681187 $3.00 + 0.00 Copyright Q 1987 Pergamon Journals Ltd ELICITING PREFERENCES FOR ALTERNATIVE DRUG THERAPIES IN ONCOLOGY: INFLUENCE OF TREATMENT OUTCOME DESCRIPTION, ELICITATION TECHNIQUE AND TREATMENT EXPERIENCE ON PREFERENCES ANNETTE M. C. O’CONNOR, NORMAN F. Bow, PADRAIG WARDE, L. STOLBACH and JAMES E. TILL Instituteof Medical Science, School of Graduate Studies, University of Toronto, and The Ontario Cancer Institute, Toronto, Ontario, Canada M4X 1K9 zyxwvutsrqponmlkjihgfed (Received in revised form 17 March 1986) Ah&act-Several methodologic issues arise in eliciting preferences for therapy. Examples are the selection of appropriate descriptions of treatment outcomes and of elicitation techniques. Of particular importance is the correspondence of patients’ anticipated preferences for treatment to actual preferences once they have experienced treatment. Treatment outcome descriptions and elicitation techniques were compared for a hypothetical drug decision problem involving trade-offs between quality and quantity of life. Preferences of 54 cancer patients were elicited before, and 6 weeks following initiation of chemotherapy treatment. Patients’ preferences were not influenced by the way information about side effects was presented, nor the stated probability of survival at high and moderate levels. A riskless rating technique produced different preferences from those of a risky treatment choice method. Although patients experienced significant toxicity following initiation of treatment, their preferences remained stable on retest. The results raise questions about the extent to which patients are willing, at the time of decision making, to trade off survival rate for improved quality of life. INTRODUCTION When treatment decisions involve making trade-offs between quality of and quantity of life, the reliability and validity of techniques used to present information and elicit choice or consent from patients is of crucial significance. Important dimensions to consider in eliciting preferences are the way treatment effects are described, the methods of preference elicitation, and the timing of assessment. If descriptions and techniques produce consistent results before and after treatment is initiated, then clinicians can be more confident that the preferences obtained truly represent the patient’s point of view. From previous research, we know that prefer- ences may be sensitive to the way the side effects of treatment are described [l], the elicitation technique that is used [l--3], the level of proba- bility of survival that is presented [l, 4,5] and the treatment experience of the respondent [6]. However, many of these studies were conducted with healthy volunteers in laboratory settings. The few patient studies used different decision contexts with patients who were not involved with the treatment or who were interviewed well after treatment had commenced. In view of the evidence that patients’ and healthy volunteers’ responses differ [7,8] and patients’ responses are more reliable during or shortly after treatment [9], we explored the influence of description of treatment effects, elicitation technique, proba- bility level, and treatment experience on prefer- ences for a group of chemotherapy patients about to begin treatment for the first time. There was little previous information about the influence on preferences of the way side effects of treatment are described to patients. The alternatives are to describe what a “typical” patient might experience, or to attempt to be more realistic and introduce uncertainty of side effects by describing toxicity rates. In the latter approach, it is difficult to establish the proba-