The question of screening for prostate cancer appears to meet these 3 criteria. There is uncertainty about the benefit of screening, and treatment holds a potential for significant complications. Previous studies using clinical decision-analysis have shown that patients’ preferences for the outcomes of prostate cancer treatment are central to determining the optimal screening strategy.8,9 Finally, patients’ (and spouses’) preferences for these outcomes vary markedly.10
Decision-aids and prostate cancer
In the study by Schapira and VanRuiswyk, the use of prostate cancer screening after the intervention was not significantly different for the experimental and control groups (more than 80% were screened). What might explain the intervention’s lack of impact on screening behavior? A summary of clinical trials evaluating decision-aids appears to suggest that the effect of a decision-aid on screening behavior varies by subject population Table 1. In studies of unselected patients, decision-aids for prostate cancer screening appear to decrease the rate of screening. (The Mantel-Haenszel pooled relative risk estimate for these studies of unselected patients is 0.35, suggesting that decision-aids decrease screening behaviors.) Similar reductions had been observed in studies where the outcomes were intention or interest in screening.1,11 In contrast, for studies where patients were self-referred, such as men presenting for free prostate-specific antigen testing, decision-aids appear to have little effect on screening behavior. Schapira and VanRuiswyk solicited their subjects by letter. This self-selection, as the authors note, may have led to the formation of a sample of patients who were more favorably inclined to select screening. Previous research on decision-aids suggests that a predisposition for a course of action can have an impact on the choices patients make. For example, when considering the decision to circumcise a male newborn, a decision-making tool has little effect on the rate of circumcision; parents have strong preferences before receiving the intervention and are not swayed by learning more about the risks and benefits of the procedure.4
Future challenges
The literature on decision-aids shows that knowledge tends to improve the situation: patients become more certain (or less conflicted) about the choices they make, and they favorably evaluate the experience.12
So what are the goals of informed patient decision making? O’Connor13 has made the astute observation that cognitively oriented decision-aids should be expected to have their greatest impact on cognitive outcomes (eg, knowledge). It seems reasonable to expect that a principal outcome of any informed decision-making intervention will be to increase patient awareness of the core issues surrounding the options they face. Reductions in decision-associated conflict, more accurate perceptions of personal risk, and satisfaction with the decision-making process are also important outcomes. Whether such interventions change behavior appears to be a secondary concern.
Perhaps the greatest challenge for this new field of patient informatics will occur as our attention turns from the efficacy of decision-aids (the effect of the intervention in highly controlled protocol-driven clinical trials) to evaluating their effectiveness (implementation in the real world of clinical practice). What seems certain is that patients will continue to want this kind of information, with many playing a more active role in decision making and looking to their health care providers for information and guidance.