Table 3.

Multivariate analysis of significant factors in background characteristics for risk of sudden infant syndrome

Variables	Univariate		Multivariate
			Background+		All factors++
	Odds ratio (95% CI)	p	Odds ratio (95% CI)	p	Odds ratio (95% CI)	p
Bottle feeding of the birth	4.89 [1.59; 15.05]	0.006	2.74 [0.45; 16.75]	0.274	2.43 [0.17; 33.74]	0.509
Unplanned pregnancy	8.75 [3.21; 23.85]	<0.001	6.98 [2.19; 22.24]	0.001	5.22 [1.49; 18.18]	0.009
Late (month 4–9) or no prenatal care	4.25 [1.91; 9.41]	<0.001	3.65 [1.24; 10.71]	0.019	2.49 [0.73; 8.51]	0.147
≥2 previous live births	2.73 [1.19; 6.24]	0.017	2.01 [0.69; 5.86]	0.199	3.90 [1.00; 15.10]	0.048
Maternal age ≤20 or ≥35 y	3.78 [1.69; 8.41]	0.001	1.98 [0.67; 5.89]	0.216	1.18 [0.34; 4.04]	0.792
Maternal education ≤12 y	5.93 [2.62; 13.40]	<0.001	4.11 [1.48; 11.41]	0.007	4.48 [1.34; 14.94]	0.015
Single mother	3.04 [1.09; 8.54]	0.034	1.86 [0.36; 9.61]	0.457	1.87 [0.22; 16.06]	0.566
No waged income	3.15 [1.24; 8.02]	0.016	1.01 [0.26; 3.86]	0.993	1.04 [0.21; 5.10]	0.965
Exposure to smoking during pregnancy (one or both of parents smoked)	3.94 [1.62; 9.61]	0.003	2.76 [0.87; 8.71]	0.083	1.87 [0.51; 6.94]	0.348

⁺ Controlled for all background factors listed in table.

⁺⁺ Controlled for all factors that remained significant in the univariate analysis, including background factors.