Number needed to treat/harm — Flashcards

Flashcard 1: attributable risk/absolute risk reduction (epidemiology)

Answer: the difference in risk between exposed and unexposed groups (attributable risk used for risk-enhancing factors ARR used for risk-reducing interventions)

Flashcard 2: number needed to harm (NNH) (epidemiology)

Answer: The number of patients who must be exposed in order to cause 1 event.

Extra: NNH = 1/attributable risk

Flashcard 3: number needed to treat (NNT) (epidemiology)

Answer: The number of patients who must be treated in order to prevent 1 event.

Extra: NNT = 1/absolute risk reduction