Dr. Tremblay was a general practitioner at the Douglas Institute and an associate researcher at the Douglas Research Centre since 1999. He played an important role in introducing the concept of assessment of the quality of medical care using explicit and implicit criteria in Canada, in the 1980s. This concept is now used widely in North America and is recommended by the Quebec College of Physicians.
Dr. Tremblay worked closely with other former researchers, such as Drs. Thomas Brown and Maurice Dongier, and was committed to advancing research on substance abuse.