[1][2] He is also known as the developer of the Jadad Scale, the first validated tool to assess the methodological quality of clinical trials, which has been cited over 25,000 times in the peer-reviewed literature.

When he was a medical student at Xavierian Pontifical University in Bogotá, he conducted the first studies on the jargon, the chemical composition and the clinical implications of a drug called 'basuco', which soon became known worldwide as "crack" cocaine.

His doctoral thesis, entitled "Meta-analysis of Controlled Trials on Pain Relief",[10] was published and widely disseminated by the British National Health Service (NHS).

[11] As part of his doctoral work, he led the creation of the largest database of clinical trials in pain relief, developing new methods to optimize searches of the US National Library of Medicine, complementing them with manual screening of over 1.3 million pages of scholarly journals since 1948 to 1990.

[20] In 2000, Jadad moved to the University of Toronto as Professor in the Faculty of Medicine, and Inaugural Rose Family Chair in Supportive Care (a post he held until 2010), which enabled work on the reconceptualization of terms such as 'health' or a 'good death', as a means to guide the design, development, implementation and evaluation of innovations aimed at allowing people, even those living with complex chronic conditions or even terminal illnesses, to consider themselves to be healthy until the end.

During his tenure, he led research and innovation efforts to level the playing field for patients and caregivers through personalized hybrid (human and digital) coaching programs, and the use of social networks and computer-mediated communication; and to improve the quality of end-of-life care through peer-to-peer support networks, home-driven telehealth services, and a change in perspective about death and dying by healthcare professionals.

[31] This effort, which included contributions from experts in 52 countries, resulted in a new conceptualization of health as 'the ability to adapt and manage' the physical, mental or social challenges faced by individuals or communities throughout life.

Trust among payers, service-providing institutions, professionals and users of health services was the key to achieving these results with only 25% of the average expenditure across the OECD (US$500 per person annually.

[36] In 2019, he became a member of the Council of the Wise, a group of 43 experts in eight different areas charged by the government of Colombia to produce recommendations about the future of the country in the following 25 years.