By Keiller MacDuff of RNZ When the small South Island town of Timaru and its cluster of US doctors hit the front page of the Wall Street Journal last week, it highlighted New Zealand's dependence on overseas doctors, particularly in rural and regional parts of the country. It is not just Americans - New Zealand has one of the highest proportions of internationally trained doctors among developed countries. International Medical Graduates (IMGs) made up more than 40% of all New Zealand doctors last year, and about 70% of new registrations each year are overseas-trained doctors, according to Medical Council data. But 60% of overseas doctors leave after two years compared to 6% of New Zealand-trained graduates, and a new report suggests retention could be improved by more help with adapting to New Zealand society, culture and medical system.…