Purpose: To test three sets of hypotheses derived from Diff Con. The sets focussed on (a) differentiation, (b) consolidation, and (c) the relationships between the decision processes and the outcomes of decisional conflict and regret.
Method: Data from both RCT arms were pooled to test six hypotheses. Differentiation and consolidation scores were determined by calculating the difference between the values [scale: 1 (least)-5 (most)] of the most-preferred choice and its closest competitor. For brevity, we report one example hypothesis from each set: (a) related to differentiation—differentiation increases gradually over time, (b) related to consolidation—the relative value of the choices continues to change after the decision is made, and (c) related to the decision-process relationships—greater consolidation is associated with lower regret (measured by O'Connor's Decision Regret Scale).
Results: All six hypotheses were supported, though limitations were identified. (a) Differentiation: mean differentiation scores shifted from 1.25 at pre-PtDA to 1.63 at post-PtDA (N=126; F=14.67, p<.001), to 2.06 at 1-week post-decision (N=126; F=8.44, p=0.004). (b) Consolidation: mean consolidation scores shifted from 1.89 at 1-week post-decision to 2.53 at 3-months post-treatment (N=81; F=14.1, p<.001), to a non-different 2.06 at 1-year post-treatment (N=81; F=0.72, p=0.4); (c) Decision-process relationships: consolidation scores were negatively associated with regret scores at 3-months post-treatment ( r= -0.31, p<0.001) but the relationship was only a trend at 1-year post-treatment (r= -0.18, p=.08).
Conclusion: Data from this PtDA study support the hypotheses derived from Diff Con, and the tests help clarify specifics about decision processes that occur in the context of this decision.