His work addressed the variability of sickle-cell disease with special emphasis on developing low-cost models of management suitable to countries with large numbers of patients and limited resources.
He was successful and proceeded to the entrance examinations at Cambridge where, following an interview with Sir Henry Thirkill, master of Clare College, he was offered a place to study the Natural Science Tripos in September 1957.
After completing the Medical Tripos examinations in Cambridge in June 1963, he returned to the London Hospital for house jobs with the Surgical Unit and Paediatrics (1963–64) and then to the Royal United Hospital in Bath (1964–65) where he completed a six-month assignment in General Medicine and one year in Neurology before returning to London as senior house officer to Professor John Goodwin in cardiology at the Royal Postgraduate Medical School, Hammersmith.
After Hammersmith and passing the Membership of the Royal College of Physicians of London (MRCP), he sought work abroad in sub-Saharan Africa, but in the absence of suitable posts, he was persuaded by Beryl, who had spent some of her childhood in Bermuda, to apply to the Department of Medicine at the University of the West Indies (UWI), Kingston, Jamaica, where he was appointed by Professor Eric Cruickshank.
This led to the hypothesis that either the disease in Jamaica was different or that a strong symptomatic bias had resulted because reports, principally from the US, were based on sick patients attending clinics and hospitals.
After three months, and with support from the British Medical Research Council, it was decided to leave Cambridge after one year and return to Jamaica and initiate a cohort study of sickle-cell disease from birth.
The 800 children in the Cohort have now been followed for periods up to 48 years, documenting the development of haematological change, principal clinical features and causes of death with the production of 139 papers in the medical literature.
The Unit was also fortunate in attracting many visiting workers such as Professor Alan Bird from Moorfields Eye Hospital in London, who for 20 years, led a team of ophthalmologists to document the evolution of retinal disease.
Subsequent analysis found 2,442 deliveries to mothers screened at school of which 11 babies had forms of sickle cell disease which did not deviate from expected numbers.
The expertise gained in the management of 5,500 patients with sickle cell disease as well as the 800 followed from birth in the cohort study has led to many invitations to share Jamaican experience in Brazil, Greece, Nigeria, Uganda, Angola, Cameroon, Congo Brazzaville, Bahrain, Saudi Arabia and India.