As a professor at Yale and later Stanford University, his research focused on the social, environmental, behavioral and bio-medical determinants of morbidity and mortality in adults, with special emphasis on the role of workplace’in such matters.

In his role as Alcoa’s senior medical officer, he extended his research into the psychosocial causes of disease in the workforce, exploiting existing administrative data on 250,000 former and present employees.

[7] In 2006, Cullen was awarded an NIA grant to develop a model of population determinants of chronic disease, disability and death, followed by additional funding to study how employees and their families use various social and health benefit options.

[15] In South Africa in 1997, he joined a government commission reviewing the training programs in occupational and environmental health, leading to establishment of a new curricular model based on the emerging experience in the US.

[19][20] [21] PHS allows scholars from diverse disciplines to easily and securely share, link, and analyze large disparate population-level datasets (including high risk data), facilitating a shift toward multi-disciplinary team science.