Users' Guides to the Medical Literature

Abstract

Most classes of drugs include multiple compounds. The opinions of clinicians, manufacturers, and purchasers may differ as to whether a particular drug is more efficacious, safer, or more cost-effective than others in its class.¹ In this article, we review the types of evidence commonly cited to support the prescribing of a particular drug rather than another of the same class and provide a hierarchy for grading studies that compare a drug with another of the same class, expanding on our discussion in part A of this Users' Guide.²