Table 2.

Effect of different protocols on standardised detection ratio (SDR) for small invasive breast cancers (<15 mm), 1996-7*¹⁰

Protocol	SDR	Rate ratio (95%CI)
One view/single reading	0.68	1.00
One view/double reading (recall if one reader suggests)	0.93	1.37 (1.15 to 1.62)
Two views/single reading	0.97	1.43 (1.15 to 1.77)
One view/double reading (consensus)	1.00	1.47 (1.21 to 1.78)
Two views/double reading (recall if one reader suggests)	1.05	1.54 (1.26 to 1.87)
Two views/double reading (consensus)	1.12	1.64 (1.31 to 2.06)
One view/double reading with arbitration)	1.18	1.73 (1.40 to 2.13)
Two views/double reading with arbitration	1.28	1.88 (1.49 to 2.37)

*Study may be subject to biases and should not be considered a substitute for a randomised controlled trial.