Table 7.

Numbers of invasive interval cancers within one year of screening, numbers of screens and expected annual incidence from pre-screening trends, by age and period, with the maximum likelihood estimates of λ and S from the interval cancer data.

Age	Period	One-year interval cancers	Number of screens	One-year interval cancer rate	Expected annual incidence	Proportionate interval cancer rate	Estimate of λ	Estimate of S
50–54	1996–2000	44	106,661	0.00041	0.001635	0.25	0.26 (0.18–0.35)	0.83 (0.80–0.86)
	2001–2005	114	225,343	0.00051	0.001816	0.28
	2006–2009	110	206,848	0.00053	0.001996	0.27
55–59	1996–2000	43	85,072	0.00051	0.001872	0.27	0.46 (0.38–0.55)	0.92 (0.89–0.95)
	2001–2005	141	237,884	0.00059	0.002114	0.28
	2006–2009	120	210,214	0.00057	0.002358	0.24
60–64	1996–2000	40	71,624	0.00056	0.002096	0.27	0.10 (0.04–0.17)	0.84 (0.82–0.86)
	2001–2005	83	178,912	0.00046	0.002292	0.20
	2006–2009	91	204,408	0.00045	0.002478	0.18
65–69	1996–2000	25	65,897	0.00038	0.001912	0.20	0.17 (0.06–0.30)	0.77 (0.73–0.81)
	2001–2005	80	132,407	0.0006	0.001886	0.32
	2006–2009	76	131,161	0.00058	0.001864	0.31