Strengths and limitations
This analysis is based on self-reported, not observed, early infant feeding practices, hence there is the potential for information bias. However, the high number of women reporting prelacteal feeds in the intervention group (12%, 15% and 25% in Burkina Faso, Uganda and South Africa, respectively) might indicate that these questions were well understood and responded to. The PROMISE-EBF trial did not capture birth weight, however, we asked for birth weight at the 3-week interview. Using 3-week anthropometric information as a proxy for birth weight is a limitation because, our outcome of interest, early infant feeding, happened in real time before the measurements. This study does not allow us to investigate any relationship between early severe events such as neonatal death or hospitalisation due to a) sample size limitations; and b) limitation in study design resulting in healthy live children being enrolled in the follow-up where the early infant feeding questions were asked.