Table 3.

Sensitization to dog, cat, birch, and any allergen at 13 years of age in relation to the parental history of asthma and hay fever, and to pet ownership

	Pos SPT to dog at 13 y (n = 81)				Pos SPT to cat at 13 y (n = 140)
	Crude OR (95% CI)	P crude	Adj OR b (95% CI)	P adjusted	Crude OR (95% CI)	P crude	Adj OR b (95% CI)	P adjusted
Paternal hay fever	2.51 (1.53‐4.10)	<.001	2.22 (1.30‐3.87)	.005	2.28 (1.51‐3.43)	<.001	2.42 (1.53‐3.85)	<.001
Paternal asthma	2.09 (1.15‐3.80)	.016	1.44 (0.73‐2.86)	.294	1.36 (0.80‐2.33)	.26	0.92 (0.50‐1.69)	.792
Maternal hay fever	2.08 (1.26‐3.42)	.004	1.78 (1.01‐3.14)	.047	2.20 (1.46‐3.29)	<.001	2.08 (1.31‐3.31)	.002
Maternal asthma	1.74 (0.98‐3.10)	.06	1.37 (0.70‐2.65)	.356	1.34 (0.82‐2.20)	.246	1.07 (0.61‐1.87)	.812
Dog‐keeping c
Never	1.0		1.0		1.0		1.0
First year of life d	0.20 (0.09‐0.46)	<.001	0.18 (0.08‐0.44)	<.001	0.56 (0.33‐0.96)	.034	0.61 (0.35‐1.06)	.081
After first year only e	0.47 (0.24‐0.94)	.032	0.38 (0.18‐0.82)	.014	0.55 (0.31‐0.98)	.044	0.47 (0.25‐0.88)	.018
Cat‐keeping c
Never	1.0		1.0		1.0		1.0
First year of life d	0.64 (0.32‐1.27)	.199	0.77 (0.37‐1.60)	.480	0.45 (0.24‐0.81)	.009	0.50 (0.27‐0.95)	.033
After first year only e	0.25 (0.10‐0.65)	.005	0.27 (0.10‐0.74)	.010	0.41 (0.22‐0.76)	.004	0.42 (0.22‐0.80)	.009

	Pos SPT to birch at 13 y (n = 133)				Pos SPT to any allergen a at 13 y (n = 251)
	Crude OR (95% CI)	P crude	Adj OR b (95% CI)	P adjusted	Crude OR (95% CI)	P crude	Adj OR b (95% CI)	P adjusted
Paternal hay fever	1.87 (1.23‐2.86)	.004	1.81 (1.12‐2.91)	.016	1.96 (1.38‐2.79)	<.001	1.87 (1.25‐2.79)	.002
Paternal asthma	1.28 (0.73‐2.22)	.392	0.84 (0.45‐1.60)	.603	1.40 (0.90‐2.19)	.140	1.07 (0.64‐1.78)	.804
Maternal hay fever	2.66 (1.77‐4.00)	<.001	2.12 (1.36‐3.43)	.001	2.50 (1.76‐3.55)	<.001	2.28 (1.53‐3.42)	<.001
Maternal asthma	1.87 (1.16‐3.01)	.010	1.36 (0.79‐2.35)	.262	1.65 (1.10‐2.48)	.017	1.18 (0.74‐1.89)	.489
Dog‐keeping c
Never	1.0		1.0		1.0		1.0
First year of life d	0.52 (0.29‐0.93)	.026	0.53 (0.29‐0.98)	.042	0.55 (0.36‐0.84)	.006	0.58 (0.37‐0.92)	.021
After first year only e	0.74 (0.42‐1.30)	.295	0.77 (0.43‐1.39)	.387	0.73 (0.47‐1.13)	.158	0.69 (0.43‐1.11)	.126
Cat‐keeping c
Never	1.0		1.0		1.0		1.0
First year of life	0.38 (0.20‐0.73)	.004	0.43 (0.22‐0.84)	.013	0.50 (0.32‐0.80)	.004	0.58 (0.35‐0.94)	.028
After first year only e	0.38 (0.19‐0.72)	.003	0.39 (0.20‐0.77)	.006	0.52 (0.33‐0.82)	.005	0.54 (0.33‐0.87)	.012

Abbreviations: CI, confidence interval; OR, odds ratio; Pos SPT, positive skin‐prick test.

^aAt least one positive SPT when testing 10 different allergens at 13 years of age.

^bAfter multiple logistic regression adjusting for paternal hay fever, paternal asthma, maternal hay fever, maternal asthma, maternal smoking, older siblings, sex, and dog‐ or cat‐keeping.

^cAfter exclusion of all children whose families reported avoiding pet ownership during their first year of life because of asthma or allergies in other family members (n = 177).

^dComparing cat/dog‐keeping during the first year of life (regardless of cat/dog‐keeping after the first year of life) with never cat/dog‐keeping from birth to 13 years of age.

^eComparing cat/dog‐keeping after the first year of life with never cat/dog keeping from birth to 13 years of age.