A demonstration of ''less can be more'' in risk graphics

Online tools such as Adjuvant! provide tailored estimates of the possible outcomes of adjuvant therapy options available to breast cancer patients. The graphical format typically displays 4 outcomes simultaneously: survival, mortality due to cancer, other-cause mortality, and incremental survival due to adjuvant treatment.

To test whether simpler formats that present only baseline and incremental survival would improve comprehension of the relevant risk statistics and/or affect treatment intentions.

. Randomized experimental manipulation of risk graphics shown included in Internet-administered survey vignettes about adjuvant therapy decisions for breast cancer patients with ER + tumors.

Demographically diverse, stratified random samples of women ages 40 to 74 y recruited from an Internet research panel.

Participants were randomized to view either pictographs (icon arrays) that displayed all 4 possible outcomes or pictographs that showed only survival outcomes.

Comprehension of key statistics, task completion times, graph evaluation ratings, and perceived interest in adjuvant chemotherapy.

In the primary study (N = 832), participants who viewed survival-only pictographs had better accuracy when reporting the total chance of survival with both chemotherapy and hormonal therapy (63% v. 50%, P < 0.001), higher graph evaluation ratings (x = 7.98 v. 7.67, P = 0.04), and less interest in adding chemotherapy to hormonal therapy (43% v. 50%, P = 0.04; adjusted odds ratio [OR] = 0.68, P = 0.008). A replication study (N = 714) confirmed that participants who viewed survival-only graphs had higher graph evaluation ratings (x = 8.06 v. 7.72, P = 0.04) and reduced interest in chemotherapy (OR=0.67,P=0.03).

Studies used general public samples; actual patients may process risk information differently.

Taking a ''less is more'' approach by omitting redundant mortality outcome statistics can be an effective method of risk communication and may be preferable when using visual formats such as pictographs.