Table 4.

Multivariable mixed effects logistic regression for the association between select risk factors and low birth weight^a/preterm^b birth for the study period 2000–07, Blantyre, Malawi

Risk factorsc	NVAZ, HPTN, PEPI (2000–07)
	Low birth weight						Preterm birth
	A*: With NVAZ			B*: Without NVAZ			C*: With NVAZ			D*: Without NVAZ
	AOR	95% CI	P value	AOR	95% CI	P value	AOR	95% CI	P value	AOR	95% CI	P value
Birth year (per 1 calendar year)	1.01	0.91, 1.12	0.86	0.96	0.86, 1.07	0.44	1.02	0.94, 1.12	0.60	1.08	0.98, 1.20	0.13
Maternal age (per 1 year)	0.97	0.95, 0.99	0.01	0.97	0.95, 1.00	0.02	0.98	0.96, 1.00	0.03	0.98	0.96, 1.00	0.10
Maternal education
None (ref)
Grade 1–8	0.98	0.71, 1.34	0.88	0.97	0.67, 1.41	0.89	1.08	0.83, 141	0.56	1.08	0.78, 1.49	0.66
Form 1 & above	1.14	0.82, 1.59	0.44	1.07	0.73, 1.57	0.73	1.09	0.83, 1.45	0.54	1.12	0.80, 1.57	0.50
Marital status
Other (ref)
Married	0.94	0.67, 1.33	0.73	0.97	0.65, 1.46	0.90	1.29	0.94, 1.77	0.12	1.48	0.99, 2.20	0.05
Infant gender
Male (ref)
Female	1.48	1.22, 1.79	<0.001	1.56	1.26, 1.95	<0.001	1.23	1.05, 1.44	0.01	1.15	0.95, 1.38	0.15

AOR=adjusted odds ratio; CI=confidence interval; ref=reference category

^a<2500 g at birth;

^b<37 weeks gestational age;

^cParity and husband’s education were not included in these models due to strong collinearity with maternal age and maternal education, respectively.

^*Model A: ICC = 0.12, Model B: ICC = 0.03, Model C: ICC = 0.09, Model D: ICC = 0.11