Table 4.

Calibration of the risk models by categories of the risk factors

				Gail model			Chen model			Barlow model
		N	Observed cases (O)	Expected cases (E)	E/O	p-value (2)	Expected cases	E/O	p-value (2)	Expected cases	E/O	p-value (2)
Age at first mammogram, y	50-54	5095	31	42	1.35	0.009	41	1.32	0.006	99	3.19	< 0.001
	55-59	3712	34	33	0.97		31	0.91		97	2.85
	60-64	4299	30	42	1.40		37	1.23		128	4.27
	65-69	603	13	7	0.54		6	0.46		19	1.46
Age at menarche, y	<12	2555	25	25	1.00	0.364	21	0.84	0.552	61	2.44	< 0.001
	12-13	5372	39	50	1.28		45	1.15		134	3.44
	> = 14	5639	43	49	1.14		48	1.12		144	3.35
Age at first live birth, y	<20	1091	9	7	0.78	0.181	7	0.78	0.370	24	2.67	< 0.001
	20-24	6393	45	53	1.18		50	1.11		151	3.36
	25-29	4200	30	42	1.40		38	1.27		104	3.47
	>29	1003	14	13	0.93		11	0.79		32	2.29
	No children	925	10	9	0.90		9	0.90		30	3.00
Body mass index	<25	3439	24	32	1.33	0.200	27	1.13	0.470	85	3.54	< 0.001
	25-29	4624	32	42	1.31		40	1.25		118	3.69
	30-34	1997	19	18	0.95		19	1.00		53	2.79
	> = 35	691	5	6	1.20		7	1.40		19	3.80
Breast density (BI-RADS)(1)	1	3019	21	27	1.29	0.063	18	0.86	0.080	37	1.76	< 0.001
	2	5480	36	49	1.36		42	1.17		131	3.64
	3	2421	29	22	0.76		26	0.90		81	2.79
	4	2140	17	19	1.12		29	1.71		72	4.24
No. of biopsies	0	13588	108	123	1.14	-	113	1.05	-	339	3.14	-
	> = 1	121	0	1	-		1	-		4	-
Affected first-degree relatives	No	12949	97	111	1.14	0.149	105	1.08	0.605	317	3.27	< 0.001
	Yes	730	10	13	1.30		10	1.00		23	2.30
Previous benign breast disease	No	12712	98	115	1.17	0.162	105	1.07	0.754	307	3.13	< 0.001
	Yes	997	10	9	0.90		9	0.90		36	3.60

⁽¹⁾1: Almost entirely fat, 2: Scattered fibroglandular densities, 3: Heterogeneously dense, 4: Extremely dense.

⁽²⁾The p-values shown in the table correspond to the Hosmer-Lemeshow C statistic. All the p-values for the chi-square test for trend were higher than 0.1.