Misconceptions about efficacy of mammography screening: a public health dilemma

OBJECTIVE This study assessed accuracy of women9s opinions about reduction in mortality from breast cancer attributable to mammography screening. DESIGN Cross sectional survey. SETTING General population of Geneva, Switzerland. PARTICIPANTS 895 randomly selected women aged 40 to 80 years, free of breast cancer. RESULTS Women estimated the proportion of deaths from breast cancer that regular mammography screening prevents in women over age 50. Only 19.3% of the respondents assessed screening efficacy realistically (that is, reduction by about one fourth); 52.0% overestimated efficacy; 26.0% “didn9t know”, and 2.6% stated that screening prevents no death. Women who believed mammography screening to be effective had more positive attitudes toward screening (higher scores of pros and lower scores of cons) and were more likely to plan to have a mammogram (both p CONCLUSIONS Most women overestimated and many were uninformed about the efficacy of mammography screening. Therefore, few women were able to take truly informed decisions about screening mammography.