Mammography dose in relation to body mass index, race, and menopausal status.

Mammography dose increases with compressed breast thickness (CBT), but few studies have examined other correlates of dose. The purpose of this study was to evaluate the relation between factors such as race, age, body mass index (BMI), CBT, and menopausal status and mammography screening dose, measured for 509 women in a US population. A multiple linear regression model was developed for dose, based on consideration of these factors as well as examination characteristics. BMI and number of films during examination were positively related to dose. After adjusting for these factors, high CBT also leads to higher dose. Whites receive lower doses than black women but differences are slight after controlling for the effects of CBT and BMI, which were significantly higher among black women. Pre-menopausal women receive higher doses, after adjusting for all other factors, than post-menopausal women. Jointly, these factors account for approximately 75% to 80% of the variability in dose among this study population. Because rates of overweight are increasing in the US, average doses from mammography may be increasing as well.