Positive predictive value of breast biopsy performed as a result of mammography: there is no abrupt change at age 50 years.

Abstract

The PPV did not change abruptly at any age for women aged 40-79 years but increased steadily, which reflects the prior probability of breast cancer at each age. Inappropriate grouping of data can lead to misinterpretation of results. Screening guidelines should not be predicated on the false assumption that this variable changes at age 50 years.