Table 1.

Selected Characteristics in Women with False Positive and Normal Mammograms

	Study Group
Characteristic	False-Positive Mammogram (n = 496)	Normal Mammogram (n = 496)
Age*, y	50.2	52.4†
Current or previous estrogen use, %	21.6	20.2
Previous breast symptom, %	12.7	7.9†
History of breast biopsy, %	6.5	2.2†
Positive family history of breast cancer, %	24.4	19.2†
Number of previous mammograms, per year‡	0.24	0.29†
Recommended follow-up to mammogram, %§
Additional mammographic views	16.8
Follow-up mammography in 6 months	41.1
Ultrasound	24.0
Biopsy	18.2

^*Age as of 7/1/83.

^†P < .05.

^‡The ratio of number of screening mammograms between 7/1/83 and the index mammogram date, divided by observation time (in years) between those two dates.

^§Of those for which specific recommendations were available from radiology report (n = 380).