Nduati 2000.

Methods	Randomized controlled trial
Participants	Pregnant women attending 4 Nairobi antenatal clinics (in the era before interventions to prevent MTCT of HIV were available locally) were offered counseling and serologic testing for HIV.  Seropositive women were invited to attend the research clinic at Kenyatta National Hospital.  Women were eligible if they resided in Nairobi and had access to municipal‐treated water.  Women were randomized to breastfeed or formula feed at about 32 weeks.    Of 2315 HIV seropositive women, 1708 (74%) returned to receive their results.  Of these, 425 (25%) were enrolled (18% of all seropositive pregnant women).  Median age of enrolled women = 23 years.  61% of women living in a 1‐room home, 74% sharing a toilet with other households, 5% owning a refrigerator.  All women had access to clean water, 76% had access to flush sanitation.  At 32 weeks gestation, 47/381 women (12%) had CD4 < 200 cells/mm3.  Median plasma viral load at this visit was 42,360 copies/mL.
Interventions	Formula feeding instead of breastfeeding. Those randomized to formula feeding were compared to those randomized to breastfeeding.
Outcomes	HIV status: The cumulative probability of HIV infection at 24 months was 36.7% (95% CI: 29.4‐44.0%) in the breastfeeding arm and 20.5% (95%CI: 14.0‐27.0%) in the formula arm (p = 0.001). Morbidity: Mbori‐Ngacha 2001 addresses morbidity: Of 401 live born, singleton or first‐born twin infants of randomized HIV‐seropositive mothers, 371 were included in the analysis of morbidity and mortality.  Incidence of diarrhea during the 2 years of follow‐up was similar in formula and breastfeeding arms (155 vs 149 per 100 person‐years, respectively).  The incidence of pneumonia was identical in the 2 groups (62/100 person years).  There were no significant differences in incidence of other recorded illnesses. Mortality The 2‐year mortality rates in both arms were similar: (breastfeeding arm:  24.4% (95%CI: 18.2‐30.7%) vs. formula feeding arm: 20.0% (95%CI: 14.4‐25.6%); p = 0.30 The rate of HIV‐free survival at 2 years was significantly lower in the breastfeeding arm than in the formula feeding arm (58.0% vs. 70.0%, respectively, p = 0.02).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	"Women were randomized to breastfeed or formula feed at about 32 weeks using computer‐generated block randomization."
Allocation concealment?	High risk	Not applicable
Blinding? All outcomes	High risk	This study was not blinded.
Incomplete outcome data addressed? All outcomes	Low risk	"We did not present secondary analyses of self‐reported feeding behavior and HIV transmission or mortality, because feeding practices may be associated with confounding variables that affect primary study outcomes."
Free of selective reporting?	Low risk	No problems apparent
Free of other bias?	Unclear risk	"Because more than one quarter of women in the formula arm admitted to noncompliance with feeding modality, our estimated breast milk transmission rate is an underestimate."