John graduated in Medicine from the University of Adelaide in 1971. After finishing his specialist training he completed a PhD in Clinical Pharmacology at Melbourne University in 1979 and was awarded a National Heart Foundation overseas postgraduate research scholarship to study epidemiology at the London School of Hygiene & Tropical Medicine. In 1986 John was appointed to the position of Chair of the Monash University Department of Social and Preventive Medicine at the Alfred Hospital.

Over the subsequent years, the Department of Epidemiology and Preventive Medicine (as it is now known) has become one of the major clinical and public research units in the country employing over 110 doctorally qualified staff and a total staff complement of 350. Currently there are 460 postgraduate students and 135 doctoral students. The department has evolved around a core of methodological skills in epidemiology, clinical medicine, biostatistics and data-management. Much of the work of the department now centres around large scale clinical trials, clinical registries and major occupational cohorts.