SIMPLER RISK GRAPHICS CAN IMPROVE UNDERSTANDING OF THE INCREMENTAL BENEFIT OF ADJUVANT CHEMOTHERAPY

Background: To help oncologists and breast cancer patients make informed decisions about adjuvant therapies, online tools such as Adjuvant! provide tailored estimates of mortality and recurrence risks.  However, the graphical format used to display these results (four horizontal stacked bars) is suboptimal and displays extra options that may not be relevant to a particular patient. We tested whether presenting information in simpler formats and with fewer options would improve comprehension of the relevant risk statistics.

Materials and Methods: 1,619 women ages 40-74 completed an Internet-administered survey vignette about adjuvant therapy decisions for a patient with an ER+ tumor. Participants were randomized to view one of four risk graphics: a base version that mirrored the Adjuvant! format, a 2-option graph that removed the “no treatment” and “chemotherapy only” options to show hormone therapy (recommended for ER+ patients) as the base option, a graph that used pictographs instead of bars, or a graph that included both changes.  Outcome measures included comprehension, time to complete the task, and graph perception ratings.

Results: Both simplifying format changes significantly improved comprehension, especially when implemented together. Compared to participants who viewed the base 4-option bar graph, respondents who viewed a 2-option pictograph version were more accurate when reporting the incremental risk reduction achievable from adding chemotherapy to hormonal therapy (77% vs. 51%, p<0.001), answered that question quicker (Median time = 28 sec. vs. 42, p<0.001), and liked the graph more (M=7.67 vs. 6.88, p<0.001).

Conclusions: When presenting adjuvant therapy options to patients for whom hormone therapy is recommended, recalibrating risk graphs to only show alternatives that include hormone therapy significantly improves comprehension of the incremental benefit of chemotherapy. Although most patients will only view risk calculators such as Adjuvant! with their clinicians, simplifying the graphical designs used by such tools may enable clinicians to spend less time explaining statistics and more time reaching a shared decision with the patient.