Informed choice about breast cancer prevention: randomized controlled trial of an online decision aid intervention
Mené à partir de questionnaires auprès de 585 femmes présentant un risque élevé de cancer du sein (âge : 46 à 74 ans), cet essai analyse l'impact d'un outil d'information en ligne sur leur intention d'utiliser un agent chimiopréventif (tamoxifène, raloxifène) et sur leur décision finale
INTRODUCTION : Tamoxifen and raloxifene are chemopreventive drugs that can reduce women's relative risk of primary breast cancer by 50%; however, most women eligible for these drugs have chosen not to take them. The reasons for low uptake may be related to women's knowledge or attitudes towards the drugs. We aimed to examine the impact of an online breast cancer chemoprevention decision aid (DA) on informed intentions and decisions of women at high risk of breast cancer.
METHODS : We conducted a Randomized Clinical Trial, assessing the effect of a decision aid about breast cancer chemoprevention on informed choices about chemoprevention. Women (n=585) aged 46 to 74 years old completed online baseline, post-test, and 3-month follow-up questionnaires. Participants were randomly assigned to either an intervention group, a standard control group that answered questions about chemoprevention at baseline, or a 3-month control group that did not answer questions about chemoprevention at baseline. The main outcome measures were whether women's intentions and decisions regarding chemoprevention drugs were informed, and whether women who viewed the DA were more likely to make informed decisions than women who did not view the DA, using a dichotomous composite variable "informed choice" [yes/no] to classify informed decisions as those reflecting sufficient knowledge and concordance between a woman's decision and relevant attitudes.
RESULTS : Analyses showed that more intervention than standard control participants (52.7% vs. 5.9%) made informed decisions at post-test, P<0.001. At the 3-month follow-up, differences in rates of informed choice between intervention (16.9%) and both control groups (11.8% and 8.0%) were statistically non-significant, P=0.067.
CONCLUSIONS : The DA increased informed decision making about breast cancer chemoprevention, although the impact on knowledge diminished over time. This study was not designed to determine how much knowledge decision makers must retain over time. Examining informed decisions increases understanding of the impact of DAs. A standard for defining and measuring sufficient knowledge for informed decisions is needed. Trial registration: ClinicalTrials.gov; number NCT00967824
Breast Cancer Research , article en libre accès, 2012