Objective: The goals of this review article are to review the importance and value of standardized definitions in clinical research, as well as to propose the necessary tools and infrastructure needed to advance nosology and medial taxonomy to improve the quality of clinical trials in the field of critical care.
Data sources: We searched MEDLINE for relevant articles, reviewed those selected and their reference lists, and consulted personal files for relevant information.
Data synthesis: When the pathobiology of diseases is well understood, standard disease definitions can be extremely specific and precise; however, when the pathobiology of the disease is less well understood or more complex, biological markers may not be diagnostically useful or even available. In these cases, syndromic definitions effectively classify and group illnesses with similar symptoms and clinical signs. There is no clear gold standard for the diagnosis of many clinical entities in the intensive care unit, including notably both acute respiratory distress syndrome and sepsis. There are several types of consensus methods that can be used to explicate the judgmental approach that is often needed in these cases, including interactive or consensus groups, the nominal group technique, and the Delphi technique. Ideally, the definition development process will create clear and unambiguous language in which each definition accurately reflects the current understanding of the disease state.
Conclusions: The development, implementation, evaluation, revision, and reevaluation of standardized definitions are keys for advancing the quality of clinical trials in the critical care arena.