Many times, we aspire for codes to be evidence-based, but how do we know what the best available evidence is? Using an analysis of entries in The Center for Health Design's (free) Knowledge Repository (an online database of healthcare-related built environment research), this session will identify some of the research trends and findings from the past 5-10 years. Using these trends, the speaker will review the evolution of several research topics, summarizing some of the implications about what we do and don't know about the relationship between design and outcomes. Attendees will learn more about the opportunities and limitations of using research in developing both codes and good design.