Epidemiological studies

I don’t understand this Health & Medical question and need help to study.

 

Complete the required Readings before posting to this Discussion. Analyzing specific examples in the text from Chapters, 7, 8 and 9, explain how types of epidemiological studies impact knowledge of diagnosis, prognosis or clinical treatment. Be sure to use vocabulary that demonstrates your understanding of epidemiological terms.

The response must be 200 words, have 3 citations with corresponding references (and the references must be peer reviewed). No WebMD, Wiki or dictionary.com.

Clinical Epidemiology: The Essentials, 5th edition. Fletcher, Fletcher & Fletcher (if you need to find book).