Table 2. Outcomes by Age, Breast Density, and Mammography Type^a.

Mammography Type, Age, Breast Density	Patients With 1 y of Follow-up, No.	Biopsy Rate, Per 1000 Examinations	Cancers, No.	Cancer Rate, per 1000 Examinations	Cancer Detection Rate, per 1000 Examinations	Sensitivity, %	Specificity, %	Positive Predictive Value–1, %b	Positive Predictive Value–3, %b
Digital Mammography
40-49 y
Nondense	13 634	17.68	39	2.86	2.71	94.9	84.9	1.78	15.35
Dense	13 655	29.00	51	3.73	2.93	78.4	82.3	1.64	11.62
50-64 y
Nondense	36 729	14.40	146	3.98	3.68	92.5	91.1	3.97	26.47
Dense	17 065	21.68	100	5.86	5.51	94.0	89.1	4.82	26.49
65-74 y
Nondense	16 301	16.99	116	7.12	6.75	94.8	92.2	8.03	41.16
Dense	4589	26.15	41	8.93	7.63	85.4	90.6	7.53	33.33
All	101 973	18.96	493	4.83	4.42	91.5	88.9	3.85	24.57
Digital Breast Tomosynthesis
40-49 y
Nondense	4305	28.34	19	4.41	4.41	100	89.6	4.09	15.57
Dense	4037	35.42	28	6.94	5.20	75.0	86.0	3.60	19.58
50-64 y
Nondense	8194	23.92	35	4.27	4.03	94.3	93.2	5.61	17.35
Dense	4345	28.31	36	8.29	7.59	91.7	94.4	8.25	27.64
65-74 y
Nondense	3113	27.95	33	10.60	9.64	90.9	94.4	14.78	36.78
Dense	939	30.88	9	9.58	9.58	100	93.9	13.64	31.03
All	24 933	28.08	160	6.42	5.82	90.6	91.3	6.29	22.29

^aBreast density was based on fourth edition Breast Imaging Reporting and Data System (BI-RADS)²⁰ categories (1, almost entirely fat; 2, scattered fibroglandular densities; 3, heterogeneously dense; and 4, extremely dense) collapsed into nondense (BI-RADS 1 or 2) and dense (BI-RADS 3 or 4).

^bPositive predictive value–1 was defined as the number of examinations with cancer detected among those with positive screenings, and positive predictive value–3 was defined as the number of examinations with cancer detected among those with biopsies performed.