Method: An experimental, online study. UK University staff and students consenting to participate were randomised by the website to one of seven conditions: YoDDA; YoDDA + process narrative; YoDDA + outcome narrative (PD / HD); YoDDA + process and outcome narrative (PD / HD); YoDDA + process and outcome narratives (HD) + value clarification task; YoDDA + two outcome narratives (PD and HD). Participants completed measures assessing: (hypothetical) choice; decisional conflict; knowledge; risk perceptions and values. The programme traced web-site utilisation.
Results: 541 people from 30 Universities took part. In the YoDDA group, 63% chose HD, 37% PD. Adding patient stories encouraged participants to make a decision, and rate an options acceptability, based on another’s choice: YoDDA + process narratives, no effect; YoDDA + oucome narrative, 10% change for PD, and 20% change for HD, story; YoDDA + process + outcome narrative, 20% change for PD, and 24% change HD, story; YoDDA + process + outcome narrative + value clarification task, same effect as without task. Knowledge scores were lower in narrative groups, mixed feelings higher and value-choice consistency lower than YoDDA only group. When asked, only 20% of participants wanted to know the choice made by another.
Conclusions: Adding stories to a decision aid discourages people from making informed decisions, i.e. decisions based on a person’s evaluation of the advantages and disadvantages of all treatment options in accordance with their values. The effect is augmented when both decision process and outcome narratives are used. The addition of value clarification tasks and/or more than one outcome narrative may counter the biasing effect of stories on people’s decisions. However, adding additional tasks and/or narrative information seems to interfer with people’s processing and/or recall of the decision aid information, and their judgments about options. Although other patient stories are supportive for people adjusting and coping with illness and new treatment regimens, people do not perceive stories about another patient’s decision as useful in helping them make decisions.