Table 6.

Estimated number of deaths up to the end of the year 2002 in the Million Women Study cohort and minimum and maximum detectable relative risks for certain common conditions

		Current versus never users		Current users of 5+ years duration versus never users
Cause of death	Expected number of deaths*	Minimum detectable RR† > 1	Maximum detectable RR† < 1	Minimum detectable RR† > 1	Maximum detectable RR† < 1
All cancers	12 600	1.06	0.94	1.08	0.92
Colorectal cancer	1200	1.20	0.82	1.25	0.77
Lung cancer	2000	1.15	0.86	1.19	0.82
Breast cancer	2800	1.13	0.88	1.16	0.85
Ovarian cancer	1100	1.20	0.81	1.26	0.76
Endometrial cancer	250	1.41	0.65	1.53	0.56
All circulatory disease	8000	1.08	0.93	1.10	0.91
Ischaemic heart disease	5000	1.09	0.91	1.12	0.88
Stroke	1700	1.16	0.85	1.21	0.81
All causes of death	23 200	1.05	0.95	1.06	0.94

^*Based on national mortality rates for 1996 in England and Wales with the assumption that death rates from causes other than breast cancer are 20% lower than the national rate and that breast cancer death rates are 30% lower than the national rate. ^†Detectable at the 95% significance level with 80% power, assuming that death rates among never users are equivalent to national rates. RR, risk ratio.