Table 4:

Logistic regression analysis of variables associated with results of DNA PCR HIV testing at screening of HIV-exposed infants aged 4–12 weeks

	Unweighted MTCT frequency	Weighted proportion (%)	Odds ratio (95% CI)	p value	Adjusted odds ratio (95% CI)	p value
Mother’s reported timing of ART initiation
During this pregnancy	34/1081	3·4%(1·5–7·6)	2·5(0·5–11·9)	0·22	2·5(0·5–11·9)	0·22
Post partum	4/33	19·1%(4·6–53·5)	16·5(1·6–169·5)	0·0224	16·7(1·6–171·5)	0·0223
Stopped ART	2/17	10·2%(2·5–33·2)	8·0(1·3–50·3)	0·0305	8·5(1·6–45·4)	0·0171
Not on ART
HIV-positive status known during	6/49	4·1%(1·3–12·5)	3·0(0·6–13·8)	0·15	3·0(0·7–13·5)	0·13
pregnancy
HIV-positive status unknown during	24/132	21·1%(12·3–33·9)	18·7(8·3–42·1)	<0·0001	19·1(8·5–43·0)	<0·0001
pregnancy
Before this pregnancy	18/1148	1·4%(0·4–4·4)	1·00(ref)	··	1·00(ref)	··
Regional strata
Blantyre	20/551	3·3%(1·8–5·8)	1·2(0·5–2·7)	0·72	1·1(0·4–2·5)	0·90
South rural	21/635	3·5% (1·5–7·7)	1·2(0·4–3·5)	0·67	1·4(0·5–3·5)	0·47
Lilongwe	27/653	4·2%(3·3–5·3)	1·5(0·8–2·9)	0·21	1·4(0·7–2·8)	0·27
North-central rural	20/621	2·8%(1·6–5·1)	1·00(ref)	··	1·00(ref)	··

Analyses are based on 2460 mother–infant pairs; 18 had missing data for mother’s reported timing of ART initiation and 27 had missing data for known HIV-positive status during pregnancy. Mother’s reported timing of ART initiation and known HIV-positive status during pregnancy were combined into a single variable. Not on ART was split into known and unknown HIV-positive status during pregnancy. MTCT=mother-to-child transmission. ART=antiretroviral therapy.