Methods for Comparing the Results of Different Studies

The reader of oral and maxillofacial implant literature is challenged to be cognizant of the quality of clinical research data. The large variety of possible study designs utilized by clinical researchers requires the reader to have a fundamental awareness of the advantages, disadvantages, and limitations of commonly utilized study designs. This article aims to provide the reader with information to make an informed decision regarding the quality of a clinical research paper, so that he or she can judge whether the information presented in any given manuscript was obtained in a manner that truly minimizes bias, in the form of systematic or random errors, and whether it warrants serious consideration for clinical decision making. Special consideration is given to scientific literature pertaining to the use of oral and maxillofacial implants. In addition, the reader is presented with a method for placing any single manuscript within a "hierarchy of evidence" enabling an "estimate of confidence" in a particular therapy. By utilizing such methods to appraise the quality of research data, clinicians and patients will be better informed when making treatment-planning decisions.