Table 1.

Data used for relative risks calculation in randomised trials on breast cancer screening.

Trial no.	First author, year of publication*	Country, study acronym	Screening method (as compared to the control group)	Follow-up period (years)		Cause of death assessment	Cancer-specific deaths used for calculation of the main relative risk associated with screening	RR	95% CI
				Intervention period	Post- intervention period
1	Shapiro et al., 199726	USA, Greater New York Health Insurance Plan	MMS + BCE every 12 months, 4 rounds	5	13	Committee unaware of screening status	Cancer-specific deaths of cancers found during the intervention period	0.77	NR
2	Tabar et al., 201120	Sweden, Two-County trial†	MMS, 2–4 rounds	7	22	Local committee	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.69	0.56; 0.85
	id.	id.	id.	id.	id.	Joint review committee‡	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.73	0.59; 0.89
2	Nyström et al.	Sweden, Ostergotland§	MMS, 2–4 rounds	7.7	9.7	Death certificates	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.90	0.73; 1.11
3	Nyström et al.1	Sweden, Malmö I	MMS every 18–24 months, 6–8 rounds	15	5	Death certificates	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.82	0.67; 1.00
4	Nyström et al.1	Sweden, Malmö II	MMS every 18–24 months, 1–7 rounds	5.8	3.3	Death certificates	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.64	0.39; 1.06
5	Nyström et al.1	Sweden, Stockholm	MMS every 24–28 months, 2 rounds	4.4	10.5	Death certificates	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.91	0.65; 1.27
6	Nyström et al.1	Sweden, Göteborg	MMS, 3–5 rounds	7 (women 39–49) and 5 (women 50–59)	7 (women 39–49) and 9 (women 50–59)	Death certificates	Cancer-specific deaths of cancers found during the intervention period plus, for the control group, incorporation of cancer-specific deaths of cancers found at first screening of this group	0.76	0.56; 1.04
7	Miller et al., 201422	Canada, NBSS I and II	MMS every year, 4–5 rounds	5	20	Committee unaware of screening status	Cancer-specific deaths of cancers found during the intervention period	1.05	0.85; 1.30
8	Moss et al., 200612	England, Age trial	MMS every 12 months, 4–6 rounds	5	6	Death certificates	Cancer-specific deaths of cancers found during the intervention period	0.83	0.66; 1.04

BCE: Breast physical examination; MMS: Mammography screening; RR: Relative risk; NBSS: National Breast Screening Study.

^*The most recent publication reporting on main trial results is displayed in the Table.

^†This trial was done in the counties of Dalarna (formerly Kopparberg) and Ostergötland.

^‡The Joint Review Committee included Two-County trial investigators (Holmberg et al., 2009¹¹) and has to be distinguished from the Independent Endpoint Committee set up by Swedish trial overviews (Nyström et al., 1993)²⁹

^§The Ostergötland county trial was part of the Two-County trial, but results specific to the Ostergötland trial were published in Nyström et al.¹