Theory meets practice: a commentary on VanderWeele’s ‘principles of confounder selection’

Excerpt

When I teach graduate students in pharmacoepidemiology they are well-trained by having taken multiple courses in epidemiologic methods and causal inference. I observe that many feel paralyzed when confronted with real data realizing that such data do not come with tags saying whether variables are common causes of the exposure and outcome or whether they are instrumental variables or colliders. How will they connect the concepts, rules, and exemptions they have learned studying causal inference to the reality of data? Tyler VanderWeele is to be applauded for having compassion with us who spend less time contemplating DAGs and still want to do non-experimental studies that lend themselves to causal conclusions. His pragmatic recommendations are actionable for a broad range of applications yet founded in principled considerations. I tried to put them to a test. …