Table 1 Study endpoint definitions

Knowledge of infant feeding recommendations (early postnatal interviews)

This was a total score out of 3, each question coded as correct or incorrect, with a higher score indicating better knowledge:

• defining exclusive breastfeeding correctly

• identifying exclusive breastfeeding as the recommended feeding method for all infants

• identifying exclusive breastfeeding as the recommended feeding method for HIV-exposed infants

Infant feeding practices (6-week postnatal interviews)

This was classified in three unordered categories:

(i) Exclusive breastfeeding defined as:

• currently breastfeeding; and

• never administered other food or fluids to the infant

(ii) Mixed feeding defined as:

• currently breastfeeding; and

• ever administered other food or fluids to the infant

(iii) Not currently breastfeeding:

• this included women who may have initiated breastfeeding and ceased prior to the 6-week interview as well as those who had exclusively replacement fed their infant since delivery

Knowledge of HIV treatment and transmission (6-week postnatal interviews)

This was a total score out of 8 questions, each coded as correct or incorrect, with a higher score indicating better knowledge:

• HIV viral load knowledge (meaning of a suppressed viral load)

• role of a suppressed viral load in sexual transmission

• role of a suppressed viral load in MTCT through breastmilk

• when to test for HIV

• the role of ART in improving health (2 questions)

• that ART is lifelong

• the role of CD4 count measurement