The probability-tradeoff technique may be used to assess treatment preferences in dichotomous choices. In this feasibility study, it was used to elicit benign prostatic hyperplasia (BPH) patients' attitudes towards three different treatments. Eighty-seven male outpatients used rating scales and the standard gamble to indicate the extents to which they were free of BPH symptoms. Paired descriptions of "watchful waiting" (WW), treatment with an alpha blocker (AB), and transurethral resection of the prostate (TURP) were presented, and the probability-tradeoff technique was used to obtain treatment-preference scores. The tradeoff task identified six internally consistent preference-order subgroups. The majority (n = 55; 63.2%) were in the two subgroups in which TURP was the least-preferred treatment. Compared with the other respondents, the members of these two subgroups reported significantly higher utilities for their BPH symptom status (89 vs 79; t = 2.87; p < 0.0005). Within each subgroup, preference scores for the middle- and top-ranked treatments were computed relative to the bottom-ranked treatment; for both WW and AB, significant across-subgroup differences were observed. In this preliminary study the probability-tradeoff technique was feasible, able to identify unique preference-order subgroups, and able to generate apparently meaningful preference scores in a clinical situation involving three alternative treatments. Further development of tradeoff tasks as the value-clarification component of decision aids for individual patients seems warranted.
Health technology assessment