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 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 treatment decision, and (b) a bar exercise to help him determine the relative weighting of those attributes. Patients went through the 1-1.5 hr Decision Aid after diagnosis and initial consultation but before treatment decision making. Telephone follow-up interviews were conducted after patients made their decisions with their physician (Followup1), and 3 months later (Followup2). Outcome measures included Decisional Conflict Scale, Preparation for Decision Making Scale, and Regret. A subset of ValEx patients completed an Exit interview immediately after using the Aid to provide us with more insight into the patient experience.
Result: A total of 121 patients participated, 58 Inf and 63 ValEx subjects. There were no statistically significant between-group differences in demographic characteristics. Decisional conflict did not differ significantly between groups: it decreased continuously over time in both groups from before the Decision Aid (means 35.2 and 34.2, Inf and ValEx, respectively, scale-max 65 [F(1,105)=126.6, p=.000]); the largest decrease occurred between the Decision Aid and Followup1 (final means 26.6 and 25.9, respectively [F(1,105)=4.6, p=.03]. There was no significant difference between the groups’ regret, (means 7.6 and 7.2, Inf and ValExp, respectively, max 25) or Preparation for Decision Making scores immediately following the Decision Aid (means 29, scale-max 40). However, at Followup1, the ValEx group was trending toward better preparation (mean 31.5) than the Inf group (mean 28.9) [F(1,109)=3.54, p=.06]. Exit interviews with a subset of ValEx participants suggest that each values clarification exercise was deemed particularly helpful to a unique subset of patients but that it would be very difficult to predict which individuals would be helped by each exercise.
Conclusion: Including the two values clarification exercises may lead to better Preparation for Decision Making but each exercise appears to offer unique benefit to particular individuals.
Candidate for the Lee B. Lusted Student Prize Competition