Table 1.

Cancer detection rate (CDR) and recall to assessment for digital mammography (DM) and digital breast tomosynthesis (DBT), overall and by screening round.

	Digital Mammography (2D)	Digital Breast Tomosynthesis (with synthetic 2D)	Rate Ratio (95% CI)b
Cancers detected at screening
All screening examinations Number of detected BCs [N screens in analysis]; CDR per 1000 screens	205 [37,436 screens] 5.48/1000	402a [46,343 screens] 8.67/1000	1.58 (1.34–1.87)
First (prevalent) screening round Number of detected BCs [N screens in analysis]; CDR per 1000 screens	38 [6,412 screens] 5.93/1000	74 [8,569 screens] 8.64/1000	1.46 (0.99–2.15)
Repeat (incident) screening round Number of detected BCs [N screens in analysis]; CDR per 1000 screens	167 [31,024 screens] 5.38/1000	328a [37,774 screens] 8.68/1000	1.61 (1.34–1.94)
Recall for further assessment
All screening examinations Number of recalls [N screens in analysis]; recall percentage	1,201 [37,436 screens] 3.21%	1,180 [46,343 screens] 2.55%	0.79 (0.73–0.86)
First (prevalent) screening round Number of recalls [N screens in analysis]; recall percentage	477 [6,412 screens] 7.44%	331 [8,569 screens] 3.86%	0.52 (0.45–0.60)
Repeat (incident) screening round Number of recalls [N screens in analysis]; recall percentage	724 [31,024 screens] 2.33%	849 [37,774 screens] 2.25%	0.96 (0.87–1.06)

^aOne case was identified during the screening process due to clinical findings rather than a screening abnormality (exclusion of that case from analysis does not alter the estimated rate ratio).

^bRate ratio with 95% CI shown in bold indicate statistical significance.