<P> In medicine and statistics, gold standard test is usually diagnostic test or benchmark that is the best available under reasonable conditions . Other times, gold standard is the most accurate test possible without restrictions . </P> <P> Both meanings are different because for example, in medicine, dealing with conditions that would require an autopsy to have a perfect diagnosis, the gold standard test would be the best one that keeps the patient alive instead of the autopsy . </P> <P> "Gold standard" can refer to the criteria by which scientific evidence is evaluated . For example, in resuscitation research, the "gold standard" test of a medication or procedure is whether or not it leads to an increase in the number of neurologically intact survivors that walk out of the hospital . Other types of medical research might regard a significant decrease in 30 - day mortality as the gold standard . </P>

Which method of blood grouping is usually referred as gold standard