Sufficient-Component Cause Model: Causal Heuristic

A heuristic is a learning tool used to simplify concepts. In epidemiology, the sufficient-component cause model described by Ken Rothman is an example of a heuristic which shows the multicausal nature of disease. Under this model, a disease can be caused by any completed "pie," which is itself comprised of component causes of the disease under investigation. Causes which are present in every "pie" are called "necessary" causes, causes which are the only component of a "pie" are called "sufficient" causes, and causes which are neither necessary nor sufficient are called "component" causes.

In the above diagram, cause A is a sufficient cause, while the remaining causes are neither necessary nor sufficient component causes.