NEJM -- The Metrics of the Physician Brain Drain

This brain drain factor was one of the biggest concerns of physicians I spoke with when I was in West Africa last spring...Many of their classmates had left Africa to seek greener pastures abroad, contributing to the decline of healthcare in their "home countries."

NEJM -- The Metrics of the Physician Brain Drain: "ABSTRACT
Background There has been substantial immigration of physicians to developed countries, much of it coming from lower-income countries. Although the recipient nations and the immigrating physicians benefit from this migration, less developed countries lose important health capabilities as a result of the loss of physicians.
Methods Data on the countries of origin, based on countries of medical education, of international medical graduates practicing in the United States, the United Kingdom, Canada, and Australia were obtained from sources in the respective countries and analyzed separately and in aggregate. With the use of World Health Organization data, I computed an emigration factor for the countries of origin of the immigrant physicians to provide a relative measure of the number of physicians lost by emigration.
Results International medical graduates constitute between 23 and 28 percent of physicians in the United States, the United Kingdom, Canada, and Australia, and lower-income countries supply between 40 and 75 percent of these international medical graduates. India, the Philippines, and Pakistan are the leading sources of international medical graduates. The United Kingdom, Canada, and Australia draw a substantial number of physicians from South Africa, and the United States draws very heavily from the Philippines. Nine of the 20 countries with the highest emigration factors are in sub-Saharan Africa or the Caribbean.
Conclusions Reliance on international medical graduates in the United States, the United Kingdom, Canada, and Australia is reducing the supply of physicians in many lower-income countries. "...

India and the Indian subcontinent provide the largest absolute number of physicians to the recipient nations, but the relative draw on nations, as measured by the emigration factor, is actually greater for sub-Saharan Africa and is very pronounced for Caribbean countries