I've just recently looked at Australia, New Zealand, the U.S., and Greenland, because they have disaggregated data on aboriginals. In aboriginal communities in each of these countries, the rates are higher by factors ranging from 1.5 in the U.S., to ours, which is the highest.
In all of the countries but the U.S., the rates are going up in indigenous peoples, not as dramatically as in Canada, except in Greenland.
Greenland had the same Inuit experience in the 1950s. Their rates went way down because of an excellent program. It bottomed out in 1987 and their rates are now higher than the Inuit of Canada.
It is related to program delivery in a sustained, committed, well-funded, participatory fashion, engaging communities and making sure the capacity exists in those communities with the kind of health professionals who know the circumstances of those communities.
I might add why it works in the U.S., just to say that they have program indicators, and every state reports every year on their performance.