Chapter 3 Directed Acyclic Diagrams (DAGs)

3.1 Overview

Purpose: For each exposure, we used the directed acyclic graph (DAG) framework to identify potential confounders from the broader set of exposures used in the analysis. We did not adjust for characteristics that were assumed to be intermediate on the causal path between any exposure and the outcome, because while controlling for mediators may help adjust for unmeasured confounders in some conditions, it can also lead to collider bias. As DAG’s were hand-drawn and are complex for the large number of exposures, we show an example DAG here and then list all potential considered for each exposure in a table below.

Interpretation: The DAG below shows the set of adjusted-for exposures and unadjusted-for exposures for the estimated association between maternal weight and child growth faltering. Grey variables are on the causal pathway and are not adjusted for, while blue variables were considered potential confounders and adjusted for. Note collinear variables like maternal BMI are shown as on the causal pathway in this DAG, which may not be biologically accurate, but they were not adjusted for so are included with the potential mediators.

Implications: Given the exposures measured in each study, we attempted to maximally adjust for confounding without adjusting for mediators on the casual pathway, which would remove part of the effect of the exposure on the outcome. Confounders were not measured in every cohort, so there could be residual confounding in cohort-specific estimates, and actual DAGs will look different across cohort-specific estimates for each study.

3.2 Simplified example DAG:

3.3 DAG used: Association between maternal weight and child growth faltering

3.4 Table of Adjustment Covariates

Exposure	Potential adjustment covariates
# of children <5 in HH	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
# of people in HH	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
# of rooms in HH	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of people in HH , # of children <5 in HH , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Any wasting <6 mo.	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of measurement , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Birth length (cm)	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Birth order	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Single parent , # of rooms in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Birthweight (kg)	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Breastfed hour after birth	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Child delivered at home	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Clean cooking fuel usage	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH, Birth order , Treats drinking water , Improved floor , Improved sanitation , Safe water source
Diarrhea <24 mo. (% days)	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of measurement , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Diarrhea <6 mo. (% days)	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of measurement , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Excl/Pred breastfed <6mo.	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of measurement , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Father’s age	Treatment arm , Mother’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Father’s education	Treatment arm , Mother’s age , Father’s age , Mother’s education , HH wealth , Mother’s height , Mother’s weight , BMI , Father’s height , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Father’s height	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Single parent , # of rooms in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Gestational age at birth	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
HH food security	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , Vaginal birth , Child delivered at home , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
HH wealth	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of people in HH , # of children <5 in HH , Birth order
Improved floor	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Birth order , Treats drinking water , Clean cooking fuel usage, Improved sanitation , Safe water source
Improved sanitation	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Safe water source
Mother’s age	Treatment arm , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Mother’s BMI	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Mother’s education	Treatment arm , Mother’s age , Father’s age , Father’s education , HH wealth , Mother’s height , Mother’s weight , BMI , Father’s height , Gestational age at birth, Birthweight (kg) , Birth length (cm) , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Mother’s height	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Father’s height , Single parent , # of rooms in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Mother’s weight	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Persistent wasting <6 mo.	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Vaginal birth , Child delivered at home , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of measurement , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Safe water source	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation
Single parent	Treatment arm , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , # of rooms in HH , # of people in HH , # of children <5 in HH , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Small for gestational age	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Treats drinking water , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source
Treats drinking water	Treatment arm , Child sex , Mother’s age , Father’s age , Mother’s education , Father’s education , HH wealth , HH food security , Mother’s height , Mother’s weight , BMI , Father’s height , Single parent , # of rooms in HH , # of people in HH , # of children <5 in HH , Month of Birth , Birth order , Clean cooking fuel usage, Improved floor , Improved sanitation , Safe water source