Table 2. Consultations for infection in the first year of life in children with leukaemia and matched controls.

	Any childhood leukaemia				Childhood acute lymphoblastic leukaemia
	Cases	Controls			Cases	Controls
Consultations	No. (%)	No. (%)	OR (95%CI)	P-value	No. (%)	No. (%)	OR (95%CI)	P-value
	(n=162)	(n=2125)			(n=112)	(n=1435)
At least one consultation for infection	102 (63)	1323 (62)	1.05 (0.69, 1.59)	0.83	72 (64)	928 (65)	1.05 (0.64, 1.74)	0.84
Total consultations for infections
0	60 (37)	802 (38)	1.00	0.03a	40 (36)	507 (35)	1.00	0.01a
1–2	46 (28)	764 (36)	0.84 (0.53, 1.34)	(0.08)b	29 (26)	544 (38)	0.78 (0.44, 1.37)	(0.05)b
⩾3	56 (35)	559 (26)	1.48 (0.91, 2.43)		43 (38)	384 (27)	1.70 (0.94, 3.08)
Mean (s.d.)	2.0 (2.4)	1.8 (2.3)	1.06 (0.98, 1.13)c	0.14c	2.3 (2.6)	1.9 (2.4)	1.08 (1.00, 1.16)c	0.08c
At least one consultation for
Upper respiratory tract infections	79 (49)	859 (40)	1.56 (1.08, 2.27)	0.02	56 (50)	602 (42)	1.59 (1.02, 2.49)	0.04
Lower respiratory tract infections	11 (7)	129 (6)	1.22 (0.62, 2.39)	0.56	9 (8)	94 (7)	1.42 (0.67, 3.04)	0.36
Otitis media	14 (9)	231 (11)	0.74 (0.41, 1.34)	0.31	11 (10)	167 (12)	0.83 (0.42, 1.64)	0.59
Conjunctivitis	35 (22)	449 (21)	1.06 (0.70, 1.60)	0.79	30 (27)	317 (22)	1.39 (0.87, 2.22)	0.17
Gastrointestinal infections	15 (9)	125 (6)	1.69 (0.93, 3.06)	0.08	11 (10)	79 (6)	1.89 (0.93, 3.84)	0.10
Urinary tract infections	1 (1)	21 (1)	0.53 (0.07, 4.08)	0.54	1 (1)	17 (1)	0.64 (0.08, 5.10)	0.66
Fungal infections	16 (10)	214 (10)	0.95 (0.54, 1.66)	0.85	11 (10)	153 (10)	0.85 (0.43, 1.66)	0.62
Chicken pox	9 (6)	50 (2)	2.41 (1.14, 5.09)	0.02	7 (6)	37 (3)	2.62 (1.12, 6.13)	0.04

^aTest for difference in odds between categories.

^bTest for trend across categories.

^cOdds of disease per infection increase and associated P-value.