What does "General Practice" mean here? General practice medicine?

In the UK a General Practice is where you would meet your local doctor, or GP. It's general, because they have to keep your eye out for everything. When you go to hospital you encounter specialists.

It means the same thing in the U.S. but the term 'General Practice' has been largely replaced by 'Family Practice'. I suspect that lets general practicioners assume a specialty - as if they could then specialize in everything.

In this usage, though, I think it likely that "The National General Practice Study of Epilepsy" has some special meaning. In accounting, GAAP means Generally Accepted Accounting Practices, but it's much more specific than just saying they've written down a lot of stuff that lots of people sometimes do.