The domain of applied epidemiology has been characterized by the following five core purposes : 

1) Synthesis of results of etiologic studies as input to practice-oriented policies;

2) Description of the disease and risk-factor patterns as information to set priorities;

3) Evaluation of public health programs, laws, and policies; 

4) Measurement of patterns and outcomes of delivery of public health services and health care practice

5) Communication of epidemiologic findings effectively to health professionals, different decision-makers, and the public. 

When compared with classical epidemiology, particularly as carried out in academia, those involved in applied epidemiology face a greater sense of urgency, use data covering a range of quality, and more often learn the methods of epidemiology on the job through experiential learning.