Depending on the type of question, there are several tools that will address answer your question. Bibliographic databases, data sets, government organizations' sites, and so much more.
1. Before beginning your search, think about how much literature you expect to find on the topic. This will help as you construct your search, and prompt you to reach out to a librarian.
Pre-Digested Evidence-Based Sources (see Health Measurements & Indicators tab)
Scholarly Bibliographic Databases: it is important to consider the Public Health domain to determine the most appropriate databases
Grey Literature and Other Resources