Mammography in 53,803 women from the New Hampshire mammography network.
OBJECTIVE
To describe measures of mammography performance in a geographically defined population and evaluate the interpreter's use of the Breast Imaging Reporting and Data System (BI-RADS).


METHODS
Mammographic data from 47,651 screening and 6,152 diagnostic examinations from November 1, 1996, to October 31, 1997, were linked to 1,572 pathologic results. Mammographic outcomes were based on BI-RADS assessments and recommendations reported by the interpreting radiologist. The consistency of BI-RADS recommendations was evaluated.


RESULTS
Screening mammography had a sensitivity of 72.4% (95% CI: 66.4%, 78.4%), specificity of 97.3% (95% CI: 97.25%, 97.4%), and positive predictive value of 10.6% (95% CI: 9.1%, 12.2%). Diagnostic mammography had higher sensitivity, 78.1% (95% CI: 71.9%, 84.3%); lower specificity, 89.3% (95% CI: 88.5%, 90.1%); and better positive predictive value, 17.1% (95% CI: 14.5%, 19.8%). The cancer detection rate with screening mammography was 3.3 per 1,000 women, with a biopsy yield of 22.4%, whereas the interval cancer rate was 1. 2 per 1,000. Nearly 80% of screening-detected invasive malignancies were node negative. The recall rate for screening mammography was 8. 3%. Ultrasonography was used in 3.5% of screening and 17.5% of diagnostic examinations. BI-RADS recommendations were generally consistent, except for probably benign assessments.


CONCLUSIONS
The sensitivity of screening mammography in this population-based sample is lower than expected, although other performance indicators are commendable. BI-RADS "probably benign" assessments are commonly misused.
Poplack
S P
SP
Departments of Radiology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr, HB 7999, Lebanon, NH 03756, USA. steven.p.poplack@hitchcock.org
Tosteson
A N
AN
Grove
M R
MR
Wells
W A
WA
Carney
P A
PA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008875:Middle Aged; D009513:New Hampshire; D012044:Regression Analysis; D012680:Sensitivity and Specificity