Helping patients to reach decisions regarding their treatment: Do 'non-directive' approaches cause systematic bias?

Many patients want help in considering medical information relevant to treatment decisions they have to make or agree to. The present research investigated whether focussing on particular issues relevant to a medical treatment decision (using an apparently non-directive procedure) could systematically bias a treatment decision.

In a randomized design, participants (community volunteers, n = 146) were given standard information about treatment of cardiac risk factors by medication (statins). There were four experimental interventions in which the participants focussed on the likely personal relevance of subsets of the information previously given (positive, negative, or mixed aspects) or on irrelevant information. Participants were asked to rate their anticipated likelihood of accepting treatment before and after the experimental intervention.

The rating of acceptance of treatment was significantly increased by positive focussing; negative focussing did not significantly alter the decision rating.

The results partially replicate similar studies in health screening decisions. Reasons for the differences in results from those obtained in screening studies are considered. It is suggested that negative focussing may have less effect in decisions in which there are few risks. Statement of contribution What is already known on this subject? Decision-making in the context of health behaviour change has been widely described, but there are few experimental studies testing hypothesised strategies. 'Non-directiveness' is often regarded as desirable because it supposedly allows exploration of the decision without influencing it. Previous studies on health screening (but not treatment) have shown that health decision outcomes can be systematically influenced by the way in which a 'non-directive' intervention is implemented. This can be accounted for by a modified subjective expected utility theory previously applied to both health screening and child vaccination decisions. What does this study add? The hypothetical decision about whether or not, in future, to take statins for elevated cholesterol levels was influenced by positive but not by negative focussing. Results were consistent with the theoretical framework. This study extends previous work on influences on the decision to undertake health screening and vaccination to treatment offered as secondary prevention. 'Non-directive' approaches to helping facilitate decisions can modify those decisions, and as such cannot be regarded as non-directive.