The column states that "many Canadians come to the US for treatment." But friends of mine in Canada who live in a large city and know people at all financial levels have never heard of anyone going to the US because they couldn't get medical care in Canada.We do need national health insurance like the Canadian system. The key is that in Canada, as the article states, the government sets doctors' fees. Canadian doctors, my friends tell me, are very comfortable, but they aren't filthy rich like many US doctors are. American doctors and hospitals are worried that if we had a national health care plan like Canada's, they couldn't overcharge. Marilyn M. Yelle, Garberville, Calif. Letters are welcome. Only a selection can be published, subject to condensation, and none acknowledged. Please address them to "Readers Write," One Norway St., Boston, MA 02115.