Table 1. Parameters of the screening model.

Model component	Parameter	Baseline estimate	Mininum estimate	Maximum estimate	Reference
Tumour induction due to radiation risk	Dose (mSv)	3	1	5	Peer et al (1993)
	The lifetime probability of tumour induction	0.51	0.28	0.83	Preston et al (2002)
Preclinical tumour growth	Mean preclinical period (years)
	<50 years	1.9	0.63	3.17	Peer et al (1996); Tilanus-Linthorst et al (2007); Kriege et al (2006)
	50–70 years	3.7	1.23	6.17
	>70 years	4.5	1.50	7.50
	s.d. (years)
	<50 years	0.63	0.21	1.05	(Peer et al, 1996; Tilanus-Linthorst et al, 2007; Kriege et al, 2006)
	50–70 years	0.51	0.17	0.85
	>70 years	1.06	0.35	1.77
	Tumour-doubling times (days)
	<50 years	80	27	133	Peer et al (1996); Tilanus-Linthorst et al (2007); Kriege et al (2006))
	50–70 years	157	52	262
	>70 years	188	63	313
Risk of developing breast during life	BRCA1 probability function
	Lifetime risk at age 70 years	0.80	0.71	0.84	Easton et al (1995); Ford et al (1998)
	Mean age (years)	53.9	43.9	63.9
	s.d. (years)	16.5	5.5	28
	BRCA2 probability function
	Lifetime risk at age 70 years	0.76	0.69	0.76a	Easton et al (1995); Ford et al (1998)
	Mean age (years)	58.5	48.5	68.5
	s.d. (years)	13.8	4.6	23
Sensitivity	Sensitivity of mammography at age <40 years	0.333	0.279	0.397	Kerlikowske et al (2000)
	Sensitivity of mammography at age 40–49 years	0.389	0.326	0.464
	Sensitivity of mammography at age 50–54	0.556	0.466	0.663
	Sensitivity of mammography at age 55–59 years	0.697	0.584	0.832
	Sensitivity of mammography at age ⩾60 years	0.838	0.702	1
	Sensitivity of MRI for all age groups	0.770	0.593	1	Warner et al (2008)
Specificity	Specificity of mammography at age <40 years	0.961	0.924	1	Kerlikowske et al (2000)
	Specificity of mammography at age ⩾40 years	0.946	0.909	0.984
	Specificity of MRI for all age groups	0.863	0.745	1	Warner et al (2008)
Death rate	Average life expectancy population (years)	79	—	—	www.RIVM.nl
	5-year survival rate breast cancer patients				www.cijfersoverkanker.nl
	Tumour diameter <20 mm	0.98	—	—
	Tumour diameter 20–50 mm	0.86	—	—
	Tumour diameter >50 mm	0.62	—	—

Minimum and maximum estimates correspond with two times the s.d. For a detailed description of the parameters, see Heijnsdijk et al (2012).

^aThe maximum estimate is equal to the baseline estimate because the lifetime risk at the age of 100 years is 100%.