Effect of a computer-based decision aid on knowledge, perceptions, and intentions about genetic testing for breast cancer susceptibility: a randomized controlled trial.

Abstract

As the availability of and demand for genetic testing for hereditary cancers increases in primary care and other clinical settings, alternative or adjunct educational methods to traditional genetic counseling will be needed. To compare the effectiveness of a computer-based decision aid with standard genetic counseling for educating women about BRCA1 and BRCA2 genetic testing. Randomized controlled trial conducted from May 2000 to September 2002. Outpatient clinics offering cancer genetic counseling at 6 US medical centers enrolled 211 women with personal or family histories of breast cancer. Standard one-on-one genetic counseling (n = 105) or education by a computer program followed by genetic counseling (n = 106). Participants' knowledge, risk perception, intention to undergo genetic testing, decisional conflict, satisfaction with decision, anxiety, and satisfaction with the intervention. Counselor group measures were administered at baseline and after counseling. Computer group measures were administered at baseline, after computer use, and after counseling. Testing decisions were assessed at 1 and 6 months. Outcomes were analyzed by high vs low risk of carrying a BRCA1 or BRCA2 mutation. Both groups had comparable demographics, prior computer experience, medical literacy, and baseline knowledge of breast cancer and genetic testing, and both counseling and computer use were rated highly. Knowledge scores increased in both groups (P<.001) regardless of risk status, and change in knowledge was greater in the computer group compared with the counselor group (P =.03) among women at low risk of carrying a mutation. Perception of absolute risk of breast cancer decreased significantly after either intervention among all participants. Intention to undergo testing decreased significantly after either intervention among low-risk but not high-risk women. The counselor group had lower mean scores on a decisional conflict scale (P =.04) and, in low-risk women, higher mean scores on a satisfaction-with-decision scale (P =.001). Mean state anxiety scores were reduced by counseling but were within normal ranges for both groups at baseline and after either intervention, regardless of risk status. An interactive computer program was more effective than standard genetic counseling for increasing knowledge of breast cancer and genetic testing among women at low risk of carrying a BRCA1 or BRCA2 mutation. However, genetic counseling was more effective than the computer at reducing women's anxiety and facilitating more accurate risk perceptions. These results suggest that this computer program has the potential to stand alone as an educational intervention for low-risk women but should be used as a supplement to genetic counseling for those at high risk.