Survey results from Journal of General Internal Medicine by Alleman, Luger et al.

This article agrees with the lower number of around 13,500 US travellers going abroad. This gives an approx. landscape of 45 medical tourist facilitators, each sending approximately 300 patients abroad. 65% of these facilitators were paid by the physicians, while the remaining received compensation from the foreign provider.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077479/