Background: Evidence-based knowledge is among the most important resources in health care. However, relevant knowledge is often not implemented. There are about 100 different concepts for the "knowledge-to-practice gap".
Objectives: We conducted this review to identify relevant concepts that describe and try to overcome this situation: implementation research and knowledge translation or circulation.
Materials and methods: We initially conducted a systematic search in the databases CINAHL, Embase, ERIC, Medline, PsycINFO, Scopus, Cochrane Library and Web of Science without time or language restrictions. Owing to the huge number of relevant articles and their heterogeneity, we decided to focus on the most important concepts thus perform a narrative review.
Results: Implementation research is the scientific study of methods of systematically promoting the uptake of current research findings and other evidence-based practices into routine practice, with the aim of improving the quality and effectiveness of health services. From this definition, the affinity with health services research seems to be clear. Knowledge translation has a wider spectrum and includes the synthesis of knowledge. The term "knowledge circulation" seems to fit better, because it underlines the sharing of knowledge between research and practice.
Conclusion: Implementation research and knowledge circulation are similar research approaches, which try to develop micro-, meso-, and macro-level strategies for health services to bring knowledge into practice. This results in often complex research questions, which should be processed in interdisciplinary teams.
Keywords: Health services research; Implementation research; Knowledge circulation; Knowledge translation; Review.