Table 1.

Disease-specific mortality and all-cause mortality rates from three large, contemporary trials of cancer screening: UKCTOCS (ovarian cancer), UK AGE (breast cancer), and NLST (lung cancer)^a

Deaths/100 000 persons
Disease	Outcome	Screened	Unscreened	Reduction in deaths (95% CI)	SE	Z	P-value
Ovarian cancer1	Disease-specific mortality	292	342	50 (−9 to 109)	30	1.67	0.10
	All-cause mortality	6667	6569	−98 (−363 to 167)	135	−0.73	0.47
Breast cancer9	Disease-specific mortality	338	385	47 (−14 to 108)	31	1.50	0.13
	All-cause mortality	3947	4039	92 (−110 to 294)	103	0.89	0.37
Lung cancer10	Disease-specific mortality	1308	1620	312 (106 to 518)	105	2.98	0.003
	All-cause mortality	7024	7482	457 (18 to 896)	224	2.04	0.04

^aResults have been standardised to deaths/100 000 persons over the duration of the study. The standard errors are calculated as $SE(R_{\mathit{1}}-R_{\mathit{2}})=\sqrt{\mathit{Var}(R_{\mathit{1}})+\mathit{Var}(R_{\mathit{2}})}$ where Var(R₁) = m² (p_i(1 – p_i)/n_i). An R markdown file showing the calculations is available from the authors on request.