Table 6.

 Myeloid leukaemia (acute and chronic) 1969–2001 in a combined population based cohort of 47 679 Swedish patients with inflammatory bowel disease

	Ulcerative colitis					Crohn’s disease
	O	E	SIR (95% CI)	RR	p Value	O	E	SIR (95% CI)	RR	p Value
Overall	32	18	1.8 (1.2–2.6)	–	–	13	11	1.2 (0.6–2.0)	–	–
Sex
Male	23	10	2.2 (1.4–3.3)	1 (ref.)	0.13	5	5.6	0.9 (0.3–2.1)	1 (ref.)	0.34
Female	9	7.3	1 (0.6–2.3)	0.6 (0.3–1.2)		8	5.3	1.5 (0.7–3.0)	1.7 (0.6–5.2)
Cohort of origin
Any regional cohort	13	5.0	2.6 (1.4–4.5)	2.2 (0.9–5.0)	0.07	3	3.2	0.9 (0.2–2.8)	0.9 (0.2–3.6)	1
Inpatient register only	19	13	1.5 (0.9–2.3)	1 (ref.)		10	7.8	1.3 (0.6–2.4)	1 (ref.)
Calendar period at follow up
–1979	0	1.5	0.0 (0.0–2.4)			1	0.9	1.1 (0.0–6.4)	1 (ref.)	0.46
1980–1989	9	4.9	1.8 (0.8–3.5)	1 (ref.)*	0.15	4	2.9	1.4 (0.4–3.6)	1.2 (0.1–11)
1990–2001	23	11	2.1 (1.3–3.1)	1.8 (0.8–4.3)		8	7.2	1.1 (0.5–2.2)	1.1 (0.1–9.6)
Time of follow up (y)
1–5	6	5.6	1.1 (0.4–2.3)	0.9 (0.3–2.5)	0.19	4	3.2	1.2 (0.3–3.2)	1.5 (0.3–)	0.47
6–10	11	4.1	2.7 (1.3–4.8)	1.9 (0.8–4.6)		5	2.6	1.9 (0.6–4.5)	2.4 (0.6–9.5)
⩾11	15	7.9	1.9 (1.1–3.1)	1 (ref.)		4	5.1	0.8 (0.2–2.0)	1 (ref.)

*–1979 and 1980–1989 were combined into one category.

First year of follow up excluded.

Observed (O) and expected (E) number of myeloid leukaemia, standardised incidence ratio (SIR) with 95% confidence intervals (95% CI), and multivariate relative risks (RR) from models including all parameters in table (“ref” denotes reference category).

p values refer to type 3 tests.