Purpose: To determine if particular values clarification exercises included in a decision aid had discernible impact on patients with early-stage prostate cancer.
Method: A randomized controlled trial comparing two versions of a computerized decision aid was conducted in four centres. Patients were centrally randomized (stratified by location) to either a decision aid that included information structured to assist decision making (Inf) or a decision aid containing the same information plus two types of values clarification exercises (ValEx): (a) a ranking exercise to help the patient identify attributes affecting his decision, and (b) a bar exercise to help him determine the attributes’ relative weighting. Patients went through the 1-1.5 hr Decision Aid (DA) between diagnosis and decision making. Telephone follow-up interviews were conducted just after patients made their decisions with their physician (Followup1), 3 months later (Followup2) and a mailing >1 year later (Followup3). Outcome measures included Decisional Conflict Scale (scale 13-65), Satisfaction with Preparation for Decision Making Scale (scale 8-40), and Regret (scale 5-25).
Result: A total of 156 patients participated, 75 Inf and 81 ValEx subjects. The groups not differ significantly in their distributions of age or of education but did in their marital-status distributions: fewer married patients were in Inf (72%) than in ValEx (86%), χ2=5.2, p=.02. The groups did not differ significantly on any outcome evaluated at the time of the Decision Aid. In both groups, decisional conflict decreased continuously from before [means 34.7(Inf) vs 34.1 (ValEx)] to immediately after using the DA [means 26.6 (Inf) vs 25.8 (ValEx), F=104.0, p=.00]. Between-group differences emerged with time. The ValEx group reported better Satisfaction with Preparation at Followup1 [mean 28.9 (Inf) vs 31.5 (ValEx), t=2.36, p=.02] and again at Followup3 [mean 28.8 (Inf) vs 31.7 (ValEx), t=2, p=.046]. Regret did not differ between the groups at Followup2 [means 7.7 (Inf) vs 7.2 (ValEx), t<1] but did at Followup3 [means 8.5 (Inf) vs 7.2 (ValEx), t=2, p=.047].
Conclusion: These data suggest that including the two values clarification exercises leads to better Satisfaction with Preparation for Decision Making and to less regret but that it is necessary to evaluate the outcomes only after adequate time has passed for the decision processes to have impact.