Crofton's first medical posts, in 1937, were casual posts at military hospitals: the
Royal Herbert Hospital in Woolwich, and the
Queen Alexandra Military Hospital. In August 1939, while temporarily unemployed, he arranged a climbing trip in the French Alps with friends; they were in Italy when they discovered that war was about to break out, and managed to get back into France the day before the border closed, and from there on crowded trains back to England. The essence of the method was the use of multiple drugs taken simultaneously to reduce the chance for drug-resistant strains of the tubercle bacilli to develop, this combined with careful monitoring of patients to ensure that they adhered to the prescribed medication regime. His team were able to demonstrate that mortality, and the spread of the disease in the community, could be reduced almost to zero if medication was properly prescribed and properly taken. The incidence of tuberculosis in Edinburgh declined rapidly, and Crofton spent much of the rest of his career travelling around the UK and the wider world attempting to get this message across. From 1963 to 1966 Crofton was dean of medicine at the
University of Edinburgh Medical School. From 1966 to 1969 he worked with Andrew Douglas on their postgraduate textbook,
Respiratory Diseases. From 1969 to 1971, the period of student unrest all around the world, he was vice-principal of the university: during this time
Gordon Brown (future prime minister) was elected by the students as
rector. This had traditionally been a ceremonial post, but Brown decided to exercise his right as rector to chair the University Court. According to Crofton, Brown did the job very efficiently. From 1973 to 1976 Crofton was president of the
Royal College of Physicians of Edinburgh.
International organizations Crofton was chair of the
International Union Against Tuberculosis and Lung Disease (IUATLD) from 1984 to 1988. He helped write the
World Health Organization's guidelines for the treatment of tuberculosis before his death. In 1998, Crofton was a founding member of a new UK and international tuberculosis charity,
TB Alert. He served as TB Alert's honorary president from 1999 until his death in 2009. His support for the charity continues through The Sir John Crofton Fund to Fight TB and the Sir John Crofton Prize for TB Nursing. == Recognition ==