The gold standard (occasionally, erroneously, called the golden standard) is the term used in medicine for the test (imaging, blood test, biopsy, etc.) that is felt to be the best for diagnosis of a particular condition. The gold standard for any specific disease is not set in stone and can change over time. It is against the gold standard that any new diagnostic test is compared.
The term is also employed more widely in medicine to refer to the best procedure, treatment, research methodology etc. For example, randomized controlled trials are the gold standard for evaluating the efficacy of new drugs 3.
History and etymology
The gold standard in economics refers to the historical system by which countries' currencies were valued to a stated physical amount of gold 1,3.
The first use of gold standard in the medical literature is thought to be a review article in the Lancet in 1975 3.