Type of outcome | Scale | Potential outcome notation | Effect measure | Example interpretation |

Continuous | Additive | Causal mean difference | ‘An average increase in systolic blood pressure by 10 mm Hg’ | |

Multiplicative | Causal mean ratio | ‘An average increase in systolic blood pressure by a factor of 1.1’ or ‘by 10%’ | ||

Binary | Additive | Causal risk difference | ‘An average increase in the risk of stroke by 5 percentage points’ | |

Multiplicative | Causal risk ratio | ‘An average increase in the risk of stroke by a factor of 1.5’ |