It's formed by families who are really serious about a medical career for their kids. It helps a lot.
It should be amall and low-profile--staying far away from Chinese school/church/BSO families.
This year is the 15th BD of the one I started in my town--two dozens of our kids got into med schools so far(90% success), with two of them being faculty members of Top 5 medical schools themselves.
If you are serious about your kid's medical career, maybe you should find out and join them. Or in case there isn't one, take the initiation to start one.
Good luck!
PS. It's *very* different from a common "Ivy Club" you hear/see at your Chinese school.