Simple concept helps explain WHI to patients: focus on attributable risk.(Gynecology)

CHARLOTTETOWN, P.E.I. -- One simple change in the way risk is explained could have avoided much of the confusion that still surrounds results published last year from the Women's Health Initiative, according to Dr. Robert Reid.

"Patients have to understand the attributable risk, which is what the risk is in relation to the baseline risk, in order for it to have any meaning," said Dr. Reid, professor of obstetrics and gynecology and chair of the division of reproductive endocrinology and infertility at Queen's University, Kingston, Ont.

Consumer newspaper headlines about the Women's Health Initiative (WHI), warning that hormone therapy (HT) is associated with a 26% increase in breast cancer, misled patients into thinking that their personal risk of breast cancer is 26%. If that risk were explained to them in terms of attributable risk, they would understand that their baseline risk of breast cancer is about 10% and that the addition of combination HT increases that risk by only 1/10 of a percentage point per year, he said at the annual clinical meeting of the Society of Obstetricians and Gynecologists of Canada.

Put another way, for every 10,000 women, an extra eight cases of invasive breast cancer per year could be attributed to HT use, added Philip Hahn of the department of obstetrics and gynecology at Queen's University.

Mr. Hahn described a continuing medical education (CME) course designed by Dr. Reid that is aimed at helping physicians put the risks described in the WHI into perspective.

A questionnaire, designed by Mr. Hahn, measured the reactions of 28 ob.gyns, and 42 family physicians to the trial, as well as the effects of the CME update. A total of 36% of ob.gyns, said they felt that some of their patients had discontinued HT because of media reports on the WHI, and 11% ...