NNT in screening programs — Flashcards

Flashcard 1: Lead-time bias can be reduced by measuring _____

Answer: "back-end" survival

Flashcard 2: _____ risk reduction is the proportion of risk reduction attributable to an intervention compared to a control

Answer: Relative

Flashcard 3: Specificity values approaching 100% is desirable for ruling _____ disease (in or out)

Answer: IN

Flashcard 4: The number needed to harm (NNH) is equal to _____

Answer: 1/AR

Flashcard 5: What type of bias is caused by increased detection of diseases (e.g. cancer) with a more benign course? _____

Answer: Length-time bias

Flashcard 6: Cumulative incidence = (# of new cases over a specific period) / (number of people at risk at the _____ of the period)

Answer: beginning

Flashcard 7: What type of bias is caused by early detection being confused with increased survival? _____

Answer: Lead-time bias

Flashcard 8: The number needed to treat (NNT) is equal to _____

Answer: 1/ARR

Flashcard 9: 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 10: 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