According to the study, South Africa and Zimbabwe have the greatest economic losses in doctors due to emigration, while Australia, Canada, the UK and the US benefit the most from the recruitment of physicians educated in other countries.
The authors, led by Edward Mills, Chair of Global Health at the University of Ottawa, are now calling for destination countries to invest in training and health systems in the source countries.
The migration of health workers from poor countries contributes to weak health systems in low-income countries and is considered a primary threat to achieving the health-related Millennium Development Goals, says the study.
In 2010, the World Health Assembly adopted the first "Code of Practice on the International Recruitment of Health Personnel" that recognises problems associated with doctor migration and calls on wealthy countries to provide financial assistance to source countries affected by health worker losses.
The Code of Practice is particularly important for sub-Saharan Africa as there is a critical shortage of doctors in the region and it has a high prevalence of diseases such as HIV/AIDS.
Mills and colleagues estimated the monetary cost of educating a doctor through primary, secondary and medical school in nine sub-Saharan countries with significant HIV-prevalence. These included Ethiopia, Kenya, Malawi, Nigeria, South Africa, Tanzania, Uganda, Zambia and Zimbabwe.
The research team added the figures together to estimate how much the origin countries paid to train doctors and how much the destination countries saved in employing them.
The authors used publicly available data to access the information including published reports on primary and secondary school spending from UNESCO.
The results show that governments spend between $21,000 (Uganda) to $59,000 (South Africa) to train doctors. The countries included in the study paid around $2 billion US dollars (USD) to train their doctors only to see them migrate to richer countries, say the authors. They add that the benefit to the UK was around $2.7 billion USD and for the United States around $846 million USD.
In an accompanying editorial, Professor James Buchan from Queen Margaret University in Edinburgh, says the study raises important issues about freedom of movement. He questions whether doctors and other health workers should have cost constraints placed on their mobility when other professionals such as engineers escape such restrictions.
Buchan says that while the WHO Code may help name and shame aggressive recruiters, the post recession labour market and changing health systems will also have an impact on doctors leaving developing countries. He says several destination countries are adjusting their projected need for new staff and "the UK, for one, has drastically reduced its level of active international recruitment for most types of health professionals."