Table 3 Cox proportional hazards regression model*

Child has a birth certificate

No

67/678 (9. 9)

1

1

Yes

611/678 (90.1)

3.06 (2.45 - 3.82)

3.14 (2.41 - 4.09)

Mother HIV Status

Negative

565/678(83.3)

1

1

Positive

113/678 (16. 7)

1.19 (1.06 -1.34)

1.19 (1.03-1.37)

Marital Status

Married

145/675 (21.5)

1

Cohabiting

98/675 (14.5)

0.63 (0.46 -0.85)

Single

432/675 (64.0)

0.88 (0.74 -1.05)

Socio-economic Status

Top quintile, least poor

118/603(19. 6)

1

2^nd quintile

101/603 (16.7)

0.98 (0.81 -1.18)

3^rd quintile

104/603 (17.2)

0.82 (0.61 -1.10)

4^th quintile

154/603 (25.5)

1.15 (0.85-1.54)

Bottom quintile, poorest

126/603(20.9)

0.86 (0.63 -1.18)

Mother’s age

>35

38/677(5.6)

1

1

25–35

230/677( 34.0)

1.13(0.80 -1.59)

1.14 (0.81-1.16)

16-24

409/677(60.4)

1.29 (0.85 -1.69)

1.28 (0.94-1.74)

Total monthly family income

>R4000

15/636 (2.4)

1

1

R1200 – < R4000

193/636 (30.3)

1.49 (1.00 -2.23)

1.40 (0.89 - 2.19)

0-R1100

428/636 (67.3)

1.79 (1.24 -2.58)

1.67 (1.09 -2.55)

Educational level

Some primary

72/673 (10.7)

1

1

Some high school

402/673 (59.7)

0.96 (0.80 -1.15)

0.93 (0.75-1.15)

Completed high school

199/673 (29. 6)

0.85 (0.67 -1.08)

0.76 (0.58-1.01)

Study arm

Infant feeding arm

367/677 (54.2)

1

1

Grant arm

310/677 (45. 8)

1.06 (0.90-1.25)

1.04 (0.91 -1.19)