After selecting the case-study topics, we conducted a literature review to obtain additional background information on each topic. Web of Science, an academic citation index, served as the primary tool for our searches. The database allowed us to identify articles that referenced each CER study, such as editorials and letters that might have been used to influence interpretation of the results or promote dissemination, and empirical studies that may have either reinforced or contradicted findings from the initial CER study. We also searched PubMed to identify related articles that may not have cited the CER study and thus might have been missed in the Web of Science search. In addition, throughout the course of our discussions, informants recommended additional articles to aid our understanding of each topic.