The importance of numerical risk information in genetic counselling for breast-ovarian cancer

This paper reports findings of a prospective study of 46 women attending genetic counselling for familial breast/ovarian cancer. Clinic sessions were observed and tape-recorded; data was also collected via questionnaires and interviews before the clinic session and one and twelve months following. The women's perceptions of their risk were established both before and after counselling. Recall of numerical risk estimates was assessed at one and twelve months. Attitudes about the use of numerical probabilities and preferences for the presentation of risk infomation were also investigated. Only 9 women referred to their risks using numerical probabilities prior to genetic counselling, although 35 thought that they were more likely to develop cancer than other women. Following counselling, 60% reported that their risk was different from what they had expected. 51% indicated a preference for risk to be presented using both numerical and non-numerical formats. Analyses of the post-clinic interviews reveal a low rate of recall of numerical risk information at one and twelve months. These data suggest that the value of numerical risk estimates in genetic counselling should be reappraised.