An expert opinion (EO) is a conclusion or inference drawn by a qualified person in his or her field of expertise. It is used to help fact-finders understand complex issues in a case, and it must be based on reliable methods and data commonly relied upon by professionals in the same field. Expert opinions can be useful in legal proceedings, but their reliability depends on strict standards of relevance, accuracy, and ethics set by courts. Attorneys who understand these requirements are better equipped to prepare admissible and persuasive opinions, as well as to challenge weak or misleading ones.
As with any other manuscript, expert opinion articles should be clearly labelled, to avoid confusion with other types of research papers such as narrative reviews or consensus statements. Often, they are requested by journals only if the authors are KOLs (Knowledgeable Opinion Leaders). The differences between expert opinion and consensus statements can be difficult to determine; however, both manuscripts offer a similar format, with one author presenting his or her opinions and clinical perspective on a topic.
A good expert opinion is persuasive and reflects the views of an expert in his or her field. It should be based on a thorough understanding of relevant scientific literature and arguments, and must address potential counterarguments effectively. In addition, a well-written expert opinion should include references to support and bolster the claim(s). This helps strengthen an argument by ensuring that the opinions are not simply an individual’s speculation.