HOW SHOULD COMPLEX DATA BE PRESENTED TO HELP PATIENTS MAKE INFORMED DECISIONS?

Purpose: Shared decision-making requires that patients and healthcare workers accurately understand risks and benefits. Different formats of presentation may enhance or worsen comprehension. We aim to systematically review randomized trials assessing the comprehension of different formats of health-related risk statistics.

Method: MEDLINE, CINAHL, and PsychInfo databases were searched up to April 2013. Articles were included if randomized studies compared formats of health risk statistics and measured the outcome of knowledge and interpretation of the data.

Result: Of 1682 publications, 16 were eligible and 7 were included in the final analysis. Two types of knowledge outcomes were identified: (1) verbatim (the ability to interpret numerical values) (2) gist (the ability to choose the lowest-risk treatment option). These papers tested 5 formats –  simple numbers, pie graph, horizontal bar graph, vertical bar graph, and systematic pictographs (displaying risk statistics in groups of shaded icons). Systematic pictographs resulted in better comprehension than simple numbers judged by either verbatim (OR 0.52; 95% CI 0.46 to 0.58, p<0.01) or gist knowledge (OR 1.38; 95% 1.25 to 1.53, p<0.01). On the other hand pie graphs resulted in lower verbatim and gist knowledge when compared to the use of simple numbers. Pictographs result in better comprehension than pie graphs in verbatim knowledge (OR 0.24; 95% 0.13 to 0.44, p <0.01).

Conclusion: Systematic pictographs are more effective formats for presenting health risk information to adults. Pie graphs appear to be ineffective in communicating risk information.