such as obesity. Evidence-based policy and practice imply that interventions aimed at reducing obesity or its risk in the general population are supported by the best available research evidence on their efficacy and population impact. Decision makers also frequently seek additional information that has direct utility within their local context. Such information may be related to costs, implementation, scalability, sustainability, and factors that could facilitate or impede the success of an obesity prevention intervention. Locating useful evidence requires a clear concept of the types of information that may be useful for a particular purpose, as well as an awareness of where that information can be found.
This chapter addresses fundamental issues related to the types of evidence useful for answering a range of user questions and how that evidence can be located and gathered (Figure 5-1). Criteria for screening evidence are also addressed as background for the discussion of evidence evaluation in Chapter 6. The chapter begins by presenting an evidence typology to demonstrate how particular questions can be addressed with various methods. It then reviews potentially useful sources of evidence. The chapter concludes with a discussion of considerations in gathering the evidence.