Case Control Design - Incident Density Sampling

Dynamic Primary Study Base

Lead Author(s): Jeff Martin, MD

Case-Control Incidence Density Sampling in a Dynamic Primary Study Base

In case-control incidence density sampling in a dynamic primary study base At the time each new case is reported you sample controls from current residents or members.

Diagram: Case-Control Incidence Density Sampling in a Dynamic Primary Study Base

In the diagram below, you can see incidence-density sampling in a specified population with new subjects entering.
0218_casecontrolincidence.JPG

Sampling in a dynamic cohort gives unbiased estimate of person-time in the same way as sampling in a closed cohort

Other Considerations for Case-Control Density Sampling in a Dynamic Primary Study Base

It is easy to see the analogy between a study using this design and the graphic showing incidence density sampling nested within a cohort (pictured above). Many diseases do not have registries and it may be difficult to identify all of the cases, especially if it is a common disease.

Examples of Incidence Density Sampling

These are examples of incident density in a dynamic primary study base.