So condescending for being so wrong. You claim to be a CPA, so you should know that projections are based on past known data and are meant to be as accurate as possible, accounting for things such as expected growth rate. So it's reasonable to assume that if 1.4 million were projected, something in the neighborhood of 1.4 million went. In fact, that organization later went on to say that 1.3 million Americans went abroad for medical care in 2016. And yes, that's an estimated figure, but you know as well as I do that actual accurate figures on this sort of thing are not going to be available and that reasonable estimates and approximations are used in all things business. If you want to be unreasonable and accept neither a projection or an estimate, you can choose to, but we both know that makes you unreasonable, since I'm sure you've certified audited financials that make use of reasonable estimates.
If you read that article, the first listed, and therefore likely the most commonly given, reason is reduced cost. Even the sentence you quoted says "In addition to traveling in order to save money...", meaning that the article is recognizing your reason as secondary to cost savings. In fact, every article I encounter on the subject lists cost as the first or primary reason for medical tourism, with seeking treatments that are illegal here typically listed as a secondary or tertiary reason.
Okay, so let's take the lower number for the US. Using your numbers above and the numbers from the articles, we have 0.38% of the US population traveling for health care in 2016 vs. 0.18% of the Canadian population. In other words, US medical tourism more than doubles Canadian medical tourism by percentage of population. Again, the numbers don't add up in favor of your argument.
It's not that hard to convert raw numbers to percentages. I even did it for you above. I don't understand why you are trying so very hard to not see the obvious conclusion the numbers are giving you, that's typically the opposite of how accountants work. In any case, here's a graphic showing Canada as the top medical tourism destination in the world: