Methods
REGRESSION
We used data from randomized–controlled trials (RCTs) of 21 555 neonates in Burkina Faso conducted in 2019–2020. Newborns of mothers aged 13–19 years (adolescents) and 20–40 years (adults) were enrolled in the study 8–27 days after birth and followed for 6 months. Measurements of child’s anthropometric measures were collected at baseline and 6 months. We used multivariable linear regression to compare child anthropometric measures at birth and 6 months, and logistic regression models to obtain the odds ratio (OR) of all-cause mortality. Using multidimensional deterministic analysis, we assessed scenarios in which the difference in selection probability of adolescent and adult mothers with infant mortality at 6 months increased from 0% to 5%, 10%, 15% and 20% if babies born to adolescent mothers more often died during the first week or were of lower weight and hence were not eligible to be included in the original RCT. Using probabilistic bias analysis, we assessed the role of unmeasured confounding by socio-economic status (SES).