RESUMO
BACKGROUND: Standards for patient decision aids require that information and options be presented in a balanced manner; this requirement is based on the argument that balanced presentation is essential to foster informed decision making. If information is presented in an incomplete/non-neutral manner, it can stimulate cognitive biases that can unduly affect individuals' knowledge, perceptions of risks and benefits, and, ultimately, preferences. However, there is little clarity about what constitutes balance, and how it can be determined and enhanced. We conducted a literature review to examine the theoretical and empirical evidence related to balancing the presentation of information and options. METHODS: A literature search related to patient decision aids and balance was conducted on Medline, using MeSH terms and PubMed; this search supplemented the 2011 Cochrane Collaboration's review of patient decision aids trials. Only English language articles relevant to patient decision making and addressing the balance of information and options were included. All members of the team independently screened clusters of articles; uncertainties were resolved by seeking review by another member. The team then worked in sub-groups to extract and synthesise data on theory, definitions, and evidence reported in these studies. RESULTS: A total of 40 articles met the inclusion criteria. Of these, six explained the rationale for balancing the presentation of information and options. Twelve defined "balance"; the definition of "balance" that emerged is as follows: "The complete and unbiased presentation of the relevant options and the information about those options-in content and in format-in a way that enables individuals to process this information without bias". Ten of the 40 articles reported assessing the balance of the relevant decision aid. All 10 did so exclusively from the users' or patients' perspective, using a five-point Likert-type scale. Presenting information in a side-by-side display form was associated with more respondents (ranging from 70% to 96%) judging the information as "balanced". CONCLUSION: There is a need for comparative studies investigating different ways to improve and measure balance in the presentation of information and options in patient decision aids.