There are fears that the health services in those countries will benefit most from the decision to double the number of medical student places at Irish universities.
According to a study by the New England Journal of Medicine, Ireland loses 41.2% (6,423) of its graduates to the US, Britain, Australia or Canada.
The New England investigation coincides with a recently published Career Tracking Study commissioned by the Medical Education Task Force Group, which showed that only 65% of the polled medical graduates said they would train as a doctor again and just 50% would make all the same career choices.
The study was published in conjunction with the Buttimer report on postgraduate medical education and explored issues surrounding the career choices and retention of two groups of Irish medical graduates.
On foot of that report, Tánaiste and Health Minister Mary Harney announced last month a major package of medical education reforms, including the doubling of medical places at Irish universities - up from 305 to 725 over the next four years.
The €200 million package includes the introduction of a new graduate entry programme from 2007 and the development of the curriculum and clinical training to improve the quality of medical education.
The reforms will be implemented with immediate effect, with e4m released to allow for an additional 70 EU medical places in the autumn.
According to the study, four English-speaking First World countries increasingly depend on doctors who have immigrated. Roughly a quarter of all doctors in the US, Britain, Australia, and Canada were born elsewhere; of those, anywhere from 40% (in Australia) to 75% (in Britain) come from low-income countries.
India supplies the most doctors to the four Anglophone countries listed, followed by the Philippines and Pakistan. The biggest proportional losses tend to be in Caribbean and sub-Saharan countries.