Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Epidemiology studies can have substudies that parallel and complement other levels of clinical trials. These types of human studies can be done at a wide range of complexity, design, control, and regulation. Exploratory studies within an epidemiology study represent the equivalent of pilot studies. Examples of association studies and prognosis studies are discussed extensively in this article
