Population Health and Epidemiology Flashcards

A test's positive predictive value will increase if:

Answer: Disease prevalence increases

Higher prevalence increases the proportion of true positives among all positive tests, raising positive predictive value.

Which sampling method gives every member of a population an equal and independent chance of selection?

Answer: Simple random sampling

Simple random sampling ensures each individual has an equal, independent probability of being chosen.

A meta-analysis shows high heterogeneity (I² = 85%). This indicates that:

Answer: Study results vary substantially beyond chance

A high I² value reflects large variability between study results not explained by chance alone.

Which prevention strategy targets the whole population rather than high-risk individuals?

Answer: Population (mass) strategy

A population strategy aims to shift the entire risk distribution, as described by Geoffrey Rose.

Berkson's bias is a type of selection bias that classically arises in studies based on:

Answer: Hospitalised patients

Berkson's bias occurs when using hospital controls, distorting associations because hospitalisation depends on multiple conditions.

The case fatality rate of a disease is best defined as the proportion of:

Answer: Diagnosed cases who die from the disease

Case fatality rate is the proportion of people with the disease who die from it within a defined period.

Which study design follows exposed and unexposed groups forward to measure disease incidence?

Answer: Cohort study

A cohort study follows groups defined by exposure status over time to compare incidence of outcomes.