Session 9: Modern Case-Control Studies

Question 1

Case-Based Sampling

Answer 1

Controls are sampled from the full underlying cohort defined at the beginning of the study before any cases arise. Case-control studies using this method are sometimes called case-cohort studies.

Question 2

Cumulative Incidence Sampling

Answer 2

The method of control sampling used in traditional case-control studies; controls are sampled at the end of the study period, after all the cases arose.

Question 3

Dynamic Population

Answer 3

A population that gains and loses members; all natural populations are dynamic.

Question 4

Fixed Cohort

Answer 4

A cohort study whose membership is fixed at the beginning of the study period, no new members are allowed to join.

Question 5

Incidence Density Sampling

Answer 5

A procedure for sampling controls, in which controls are selected among subjects free of disease at the time of occurrence of the cases.

Question 6

Non-Traditional Case-Control Studies

Answer 6

Case-control studies where controls are selected from an underlying cohort, real or imagined, before the end of the study.

Question 7

Pseudo Rate Ratio

Answer 7

An odds ratio calculated from a case-control study using incidence density sampling. In the absence of selection bias, this odds ratio equals the rate ratio in the underlying cohort regardless of the disease prevalence.

Question 8

Pseudo Risk Ratio

Answer 8

An odds ratio calculated from a case-control study using case-based sampling. In the absence of selection bias, this odds ratio equals the risk ratio in the underlying cohort regardless of the disease prevalence.

Question 9

Steady State

Answer 9

A population with constant exposure distributions.