Table 2

Unadjusted incidence of gastric and colon cancers in women who were iron deficient compared with those who were not iron deficient

	Iron deficient			Non-iron deficient			P value
	Sample size (n)	Cancer* (n)	Incidence/1000 patients (95% CI)	Sample size (n)	Cancer* (n)	Incidence/1000 patients (95% CI)	P value
Anaemic women (n=9783)
Gastric cancer
Age 20–49 years	6627	4	0.60 (0.23 to 1.55)	3156	2	0.63 (0.17 to 2.31)	>0.99
20–29	379	0	–	269	0	–	–
30–39	1656	3	1.81 (0.62 to 5.31)	935	0	–	0.56
40–49	4592	1	0.22 (0.04 to 1.23)	1952	2	1.02 (0.28 to 3.73)	0.21
Colon cancer
Age 20–49 years	6627	18	2.72 (1.72 to 4.29)	3156	8	2.53 (1.29 to 4.99)	0.87
20–29	379	1	2.64 (0.47 to 14.79)	269	0	–	>0.99
30–39	1656	5	3.02 (1.29 to 7.05)	935	2	2.14 (0.59 to 7.77)	>0.99
40–49	4592	12	2.61 (1.50 to 4.56)	1952	6	3.07 (1.41 to 6.69)	0.74
Non-anaemic women (n=22 657)
Gastric cancer
Age 20–49 years	6979	0	–	15 678	3	0.19 (0.07 to 0.56)	0.56
20–29	1010	0	–	2122	0	–	–
30–39	2068	0	–	5076	0	–	–
40–49	3901	0	–	8480	3	0.35 (0.12 to 1.04)	0.56
Colon cancer
Age 20–49 years	6979	16	2.29 (1.41 to 3.72)	15 678	12	0.77 (0.44 to 1.34)	0.003
20–29	1010	0	–	2122	0	–	–
30–39	2068	1	0.48 (0.09 to 2.73)	5076	1	0.20 (0.03 to 1.12)	0.50
40–49	3901	15	3.85 (2.33 to 6.33)	8480	11	1.30 (0.72 to 2.32)	0.01

Comparisons were made using Fisher’s exact tests.
–, not applicable.
*Within 5 years of the iron deficiency test date.