Table 3.

Associations between child characteristics and antibiotic use in 8-month old children, Malmö, Sweden.

Characteristics	Use of antibiotics n (%)	Crude OR 95% CI	Adjusted OR 95% CI Model 1a)	Adjusted OR 95% CI Model 2b)	Adjusted OR 95% CI Model 3c)	Adjusted OR 95% CI Model 4d)
Gender
Girl	645 (19.2)	1.00	1.00	1.00	1.00	1.00
Boy	862 (25.0)	1.40 (1.25–1.57)	1.39 (1.24–1.57)	1.42 (1.26–1.60)	1.44 (1.28–1.62)	1.35 (1.18–1.55)
Low birth weight (< 2500 g)
No	1453 (22.0)	1.00	1.00	1.00	1.00	1.00
Yes	85 (28.7)	1.43 (1.10–1.85)	1.48 (1.14–1.93)	1.50 (1.15–1.96)	1.49 (1.13–1.96)	1.87 (1.36–2.58)
Nr in the family of brothers and sisters
Firstborn	592 (16.9)	1.00	1.00	1.00	1.00	1.00
Secondborn and more	831 (27.5)	1.86 (1.65–2.09)	1.88 (1.67–2.12)	1.89 (1.67–2.14)	1.86 (1.64–2.11)	1.39 (1.20–1.60)
Breastfeeding
0 months	71 (32.1)	1.71 (1.26–2.31)	1.75 (1.28–2.38)	1.75 (1.28–2.40)	1.64 (1.19–2.26)	1.92 (1.31–2.80)
0.1–3 months	211 (24.8)	1.19 (0.98–1.43)	1.18 (0.97–1.43)	1.11 (0.91–1.36)	1.03 (0.84–1.27)	0.97 (0.77–1.24)
3.1–6 months	430 (21.7)	1.00	1.00	1.00	1.00	1.00
6.1–8 months	72 (23.2)	1.09 (0.82–1.45)	1.11 (0.83–1.48)	1.01 (0.75–1.37)	0.99 (0.73–1.34)	0.92 (0.65–1.32)
Still breastfeeding at the age of 8 months
Yes	712 (21.2)	1.00	1.00	1.00	1.00	1.00
No	718 (23.2)	1.12 (0.99–1.26)	1.11 (0.99–1.25)	1.14 (1.01–1.29)	1.10 (0.97–1.25)	1.09 (0.94–1.26)
Allergies
No	587 (20.0)	1.00	1.00	1.00	1.00	1.00
Yes	59 (29.2)	1.65 (1.20–2.27)	1.66 (1.20–2.28)	1.56 (1.12–2.19)	1.62 (1.16–2.28)	1.40 (0.93–2.10)

^a) Adjusted for year and gender

^b) Adjusted for year, gender and parents' country of birth

^c) Adjusted for year, gender, parents' country of birth and maternal educational level

^d) Adjusted for year, gender, parents' country of birth, maternal educational level and recurrent infections