Dr Philip D'Arcy Hart

Philip Montagu D'Arcy Hart, physician and medical researcher: born London 25 June 1900; consultant physician, University College Hospital 1934-37; staff, MRC 1937-2006, scientific staff, Pneumoconiosis Research Unit 1937-48, director, Tuberculosis Unit 1946-65, grant holder 1965-93, attached worker 1993-2006; member, Expert Committee on Tuberculosis, World Health Organisation 1947-64; CBE 1956; married 1941 Ruth Meyer (one son); died London 30 July 2006.

Philip D'Arcy Hart's career was spent researching tuberculosis and other respiratory diseases. He was a pioneer in medical statistics (which underpins all good epidemiological research) and TB therapy, and in the early 1940s showed that miners' pneumoconiosis was an industrial disease, which enabled them to receive compensation.

In 1948, in what was probably the world's first large randomised controlled trial, he showed that streptomycin, then a new drug, cured TB. His work turned the tables in the fight against TB, bringing a dramatic reduction in the number of new cases as well as providing the evidence that enabled existing cases to be cured. In 1944, in another multi-centre controlled trial, he showed that a miracle cure of the common cold, endorsed by a leading cancer researcher and trumpeted by the Sunday Express, was worthless.

Hart was born in London in 1900 to a cultivated Jewish family. His father, Henry D'Arcy Hart, abandoned a career as a barrister to become a successful flower painter. His mother, Ethel, was the daughter of Samuel Montagu, first Baron Swaythling, founder of a merchant bank and Liberal MP for Whitechapel. She wanted her son to enter medicine because she greatly admired a surgeon who operated on him when he was young; but he soon decided he wanted to do research in preference to clinical work.

From Clifton School Philip D'Arcy Hart won scholarships to Gonville and Caius College, Cambridge, where he did his basic medical science training, and then to University College Hospital in London, where he did his clinical training. He then joined the medical unit there and worked his way up the ladder. Training as a medical specialist was less formalised in the 1920s than now, and hospitals were for the poor, while the rich had their illnesses at home. A hospital consultant was only nominally paid, if at all, but the appointment carried prestige and was a passport to a lucrative private practice. Hart recalled being taught by Dr John Rose Bradford that there was only one certain cure in medicine - vitamin C for scurvy.

Hart's interest in TB was evident from early on: he reported on tuberculin testing at the Pasteur Institute in Paris, and in 1932 authored a Medical Research Council report, The Value of Tuberculin Tests in Man. This showed that the test devised by Clemens von Pirquet was unreliable but that the Mantoux test, when positive, was always right and, when negative, right 98 per cent of the time. This proved useful for advising patients' families on domestic hygiene measures and was, reported The Times, "suitable for patients of the hospital class living in London, and possibly even for adults in country and private practice".

In the 1930s, mine workers who excavated the shafts got silicosis and were compensated, but those who worked at the coalface, who got a range of lung diseases broadly called pneumoconiosis did not. They were discontented, and the Government wanted to be seen to be doing something. At the suggestion of Sir Thomas Lewis, the celebrated UCH cardiologist and member of the Medical Research Council, Hart was put in charge of the investigation, and proved that the work, especially anthracite mining, did warrant industrial compensation, which was introduced.

Hart formed a tuberculosis research unit in 1946 at the MRC's request, and remained there until he "retired" in 1965. The unit was based in Hampstead, north London, and its first task was to assess the value of streptomycin, as penicillin was ineffective against TB. Hart and his deputy, Marc Daniels, used a system of random allocation designed by the eminent statistician Sir Austin Bradford Hill, which is now a standard procedure.

In 1948 they reported that streptomycin was the most powerful anti-TB treatment ever tested clinically. When the German authorities feared a post-war TB epidemic, Hart was sent to assess the risk and reported that it was unlikely, and events proved him right. Throughout most of these years (1947-54) Hart was also a member of the World Health Organisation's expert committee on tuberculosis.

Hart's other major task was to assess the French BCG vaccine, which had been available since 1921. With his statistician, Ian Sutherland, he carried out a controlled trial in over 50,000 teenagers in England, and showed it to be on average 80 per cent effective, though with unexplained local variations.

After Hart "retired" he remained with the Medical Research Council and started a new career as a cell biologist; he was classified as an "attached worker" and worked at their Mill Hill laboratories until he was 102; his last paper was published two years later. His research over these years focused on the interactions of tubercle bacteria with macrophage cells, and made new discoveries on the bacteria replicate inside cells. This has established a new era in microbial pathogenesis.

At 97 Hart was a keynote speaker at an American Society for Microbiology meeting at Copper Mountain, Colorado; at 98 he gave a keynote address at a British Medical Association conference to celebrate the 50th anniversary of the streptomycin trial; at 99 he was elected one of the first Honorary Fellows of the Academy of Medical Sciences.

He was a longstanding member of the Socialist Medical Association, had a more general interest in "social medicine", and in the Spanish Civil War was active in the pro-republican British-Spanish Medical Aid Committee. He recalled that his colleagues at UCH regarded him as a traitor when he left his consultant job to do research, and never invited him back to lecture. When he visited America during the McCarthy years he refused to sign a political disclaimer.

Philip D'Arcy Hart was a shy man, but a concise and witty speaker.

Caroline Richmond