Purpose: To examine the impact of an online decision aid (DA) intervention on informed decision making about chemoprevention.
Method: Women aged 46-74 at high risk of breast cancer were recruited from 2 U.S. HMOs. Participants were randomly assigned to 1 of 3 groups: intervention group (viewed online DA and answered post-test chemoprevention questions); standard control group (did not receive DA but answered post-test chemoprevention questions), or 3-month follow-up control group (did not receive DA or answer post-test chemoprevention questions). 585 women completed post-test and 3-month follow-up questionnaires. Using Marteau, Dormandy, and Michie’s (2001) definition of informed decisions, we created a dichotomous composite variable, “informed decision,” equal to “1” for women with sufficient knowledge (correctly answered at least 50% of gist knowledge questions) who also made a decision about chemoprevention consistent with their attitudes toward the drugs. Women with insufficient knowledge or with decisions inconsistent with their attitudes received a score of “0.”
Result: At post-test, 54% of the intervention group and 6% of the standard control group made informed decisions, OR=17.69, p<.001, 95% CI=7.56, 41.38. Informed decisions may be based on prior knowledge despite current knowledge having dropped off, so we assessed post-test knowledge with decision-making at follow-up; the intervention group (44%) made informed decisions more frequently than the standard control group (3%), OR=25.67, p<.001, CI=7.99, 82.49. At follow-up there was a trend toward the intervention group making more informed decisions (18%) than either of the control groups (12% standard control vs. 8% 3-month control), but overall this difference was not statistically significant, X2(2)=5.396, p=.067. Post-test sufficient knowledge occurred more frequently in the intervention group (62%) compared to standard control (7%), Χ2(1)=97.528, p<.001. At follow-up, the intervention group (25%) was more likely than either control group (15% standard control vs. 12% 3-month control) to have retained sufficient knowledge for an informed decision Χ2(2)=10.71, p=.005.
Conclusion: Women given a DA describing risks and benefits of tamoxifen and raloxifene were significantly more likely to make informed decisions about undergoing chemoprevention for breast cancer immediately after reading the DA. The intervention materials impacted knowledge and alignment of attitudes with decisions, but this effect faded over time. These results suggest that providing booster information and tools to help patients recall their initial decision processes may increase informed decision making.