Background: All clinicians of today know that scientific evidence is the base on which clinical practice should rest. However, this is not always easy, in particular in those disciplines, where the evidence is scarce. Although the last decades have brought an impressive production of research that is of interest to chiropractors, there are still many areas such as diagnosis, prognosis, choice of treatment, and management that have not been subjected to extensive scrutiny.
Discussion: In this paper we argue that a simple system consisting of three questions will help clinicians deal with some of the complexities of clinical practice, in particular what to do when clear clinical evidence is lacking. Question 1 asks: are there objectively tested facts to support the concept? Question 2: are the concepts that form the basis for this clinical act or decision based on scientifically acceptable concepts? And question three; is the concept based on long-term and widely accepted experience? This method that we call the "Traffic Light System" can be applied to most clinical processes.
Summary: We explain how the Traffic Light System can be used as a simple framework to help chiropractors make clinical decisions in a simple and lucid manner. We do this by explaining the roles of biological plausibility and clinical experience and how they should be weighted in relation to scientific evidence in the clinical decision making process, and in particular how to proceed, when evidence is missing.