Adoption of the double dummy trial design to reduce observer bias in testing treatments

Careful reading of these 1970s studies, however, revealed that the Croatian study was not the earliest to report the use of the double dummy trial design. The earliest reports that we have identified so far were two published in 1964 and 1965. Percy et al.,17 at the Royal Victoria Infirmary in Newcastle-upon-Tyne, UK, compared indomethacin and phenylbutazone in the treatment of a variety of rheumatic diseases. Their description of a double dummy design is clear: As it was not possible to produce identical tablets of both drugs, an inert tablet corresponding to each active compound was made and the four resultant tablet types (active Indomethacin; dummy Indomethacin; active phenylbutazone; dummy phenylbutazone) were so dispensed that a week's supply of each drug was given together with dummy tablets identical with the other drug.