Resources for Causal Reasoning in Health Services Research

Glossary of Terms

Excess proportion

Definition

Excess proportion

a proportion of cases that would not have occurred had the population not been exposed, relative to cases when the entire population was exposed (i.e. counterfactual risk when exposed is compared with counterfactual risk when unexposed)

Identifiability of causal effects

Definition

Identifiability of causal effects

the causal effect of intervention is identifiable if all backdoor paths between intervention and outcome variables can be blocked in the causal diagram; stratifying on the sufficient set removes all confounding bias in estimates of the causal effect of on

Instrumental variable

Definition

Instrumental variable

a variable relative to the total effect of exposure on outcome if there is a set of measurements, unaffected by the exposure, such the instrument is conditionally independent of the outcome given the set and the instrument is not independent of the exposure conditional on the set

Conditional probability

Definition

Conditional probability

the quotient of the joint probability of two events in the same space and the marginal probability of one of the events

Links to other Sites

• d-separation applet
• Causality
• Causal Inference Book
• Causal Inference