A physician searches for scientific information related to four areas of concern: therapy, prognosis, etiology, and diagnosis. (These are the four categories stated in the section on clinical questions of the online database NCBI PubMed. ) NCBI and PubMed.)
A medical intervention is most often therapeutic, and may or may not be drug-related, but it can also be carried out for diagnosis, screening, or teaching. The objective is to make the distinction between a useful intervention and one that is unnecessary or even dangerous.
A reviewer always seeks answers to the same basic questions in his literature review: Is it certain that more good than harm has been done? For the same efficiency, can we incur fewer costs? For the same costs, can we be more efficient?