[1] Subsequently, a 1992 JAMA article that Guyatt led proved instrumental in bringing the concept of evidence-based medicine to the world's attention.

Later, Guyatt received a Master of Science in Design, Management, and Evaluation (now known as Health Research Methodology) from McMaster University.

Guyatt is the co-editor of the Users' Guides to the Medical Literature, a comprehensive set of journal articles and a textbook for clinicians who wish to incorporate evidence-based medicine principles into their practices.

His contributions to quality of life research, randomized trials, meta-analysis and clinical practice guidelines have been considered groundbreaking.

From 1990 to 1997, Guyatt directed the residency program at McMaster University that trains physicians to be specialists in internal medicine.

The GRADE approach is now considered the standard in systematic review and guideline development with over 100 health care organizations worldwide having adopted the approach, including the World Health Organization, Centers for Disease Control, American College of Physicians and the Cochrane Collaboration.

With regard to his social activism, Guyatt previously published a regular health column on the editorial pages of the Winnipeg Free Press, and prior to that in The Hamilton Spectator.

In 1996, Guyatt received the McMaster University President's Award for Excellence in Teaching (Course or Resource Design).

[7] In 2010, he was one of 10 candidates short-listed (from a list of 117 nominees) for the BMJ Lifetime Achievement Award and ultimately finished second.