Monthly changes in WAZ (upper panels) and MUAC (lower panels) by postnatal (left panels) and prenatal (right panels) intervention arms with the dashed lines representing the control group (IFA) and solid lines representing the intervention group (IFA + BEP).
REGRESSION
Line graphs represent locally weighted scatterplot smoothing of observed values. Group differences were estimated using mixed-effects models with random intercepts for infant and random slopes for intervention time, with fixed effects including time (for WAZ), time spline variables with 6 knots (for MUAC), intervention group, and time × group interaction adjusted for allocation to the other intervention, clustering indicators (health center and randomization block), and a priori determined prognostic factors (maternal height, BMI, MUAC, hemoglobin, age and gestational age at inclusion, and parity). For the spline model of MUAC, group difference was tested by likelihood ratio test comparing a model with and without time × group interaction terms. BEP, balanced energy–protein supplement; BMI, body mass index; CI, confidence interval; ES, regression coefficient; IFA, iron–folic acid; MUAC, mid-upper arm circumference; WAZ, weight-for-age Z-score.