TY - JOUR
T1 - Directed acyclic graphs
T2 - a tool for causal studies in paediatrics
AU - Williams, Thomas C.
AU - Bach, Cathrine C.
AU - Matthiesen, Niels B.
AU - Henriksen, Tine B.
AU - Gagliardi, Luigi
PY - 2018/10
Y1 - 2018/10
N2 - Many paediatric clinical research studies, whether observational or interventional, have as an eventual aim the identification or quantification of causal relationships. One might ask: does screen time influence childhood obesity? Could overuse of paracetamol in infancy cause wheeze? How does breastfeeding affect later cognitive outcomes? In this review, we present causal directed acyclic graphs (DAGs) to a paediatric audience. DAGs are a graphical tool which provide a way to visually represent and better understand the key concepts of exposure, outcome, causation, confounding, and bias. We use clinical examples, including those outlined above, framed in the language of DAGs, to demonstrate their potential applications. We show how DAGs can be most useful in identifying confounding and sources of bias, demonstrating inappropriate statistical adjustments for presumed biases, and understanding threats to validity in randomised controlled trials. We believe that a familiarity with DAGs, and the concepts underlying them, will be of benefit both to the researchers planning studies, and practising clinicians interpreting them.
AB - Many paediatric clinical research studies, whether observational or interventional, have as an eventual aim the identification or quantification of causal relationships. One might ask: does screen time influence childhood obesity? Could overuse of paracetamol in infancy cause wheeze? How does breastfeeding affect later cognitive outcomes? In this review, we present causal directed acyclic graphs (DAGs) to a paediatric audience. DAGs are a graphical tool which provide a way to visually represent and better understand the key concepts of exposure, outcome, causation, confounding, and bias. We use clinical examples, including those outlined above, framed in the language of DAGs, to demonstrate their potential applications. We show how DAGs can be most useful in identifying confounding and sources of bias, demonstrating inappropriate statistical adjustments for presumed biases, and understanding threats to validity in randomised controlled trials. We believe that a familiarity with DAGs, and the concepts underlying them, will be of benefit both to the researchers planning studies, and practising clinicians interpreting them.
UR - http://www.scopus.com/inward/record.url?scp=85049529863&partnerID=8YFLogxK
U2 - 10.1038/s41390-018-0071-3
DO - 10.1038/s41390-018-0071-3
M3 - Review
C2 - 29967527
AN - SCOPUS:85049529863
SN - 0031-3998
VL - 84
SP - 487
EP - 493
JO - Pediatric Research
JF - Pediatric Research
IS - 4
ER -