evaluations that often are purposely excluded from systematic reviews and practice guidelines, in which studies are selected on the basis of the conventional hierarchies.
In the L.E.A.D. framework (Figure 6-1), one begins with a practical question to be answered rather than a theory to be tested or a particular study design (Green and Kreuter, 2005; Sackett and Wennberg, 1997). A decision maker, say, a busy health department director or staff member, will have recognized a certain problem or opportunity and asked, “What should I do?” or “What is our status on this issue?” Either of these questions may be of interest only to this decision maker for the particular social, cultural, political, economic, and physical context in which he/she works, and the answer may have limited generalizability. This lack of generalizability may lead some in the academic community to value such evidence less than that from randomized controlled trials (RCTs). However, data that are contextually relevant to one setting are often more, not less, relevant and useful to decision makers in other settings than highly controlled trial data drawn from unrepresentative samples of unrepresentative populations, with highly trained personnel conducting the interventions under tightly supervised protocols (see Chapter 3 for further discussion).