Follow
The best results was seen in countries that followed "ABC" approach - "B" was for "be faithful" if I remember correctly - because each of these approaches had different efficacy in different social groups and combined they worked best in all society.
There was a great book by epidemiologist Elizabeth Pisani "Wisdom of whores" which was an eye opener for me on that topic as I had quite conservative views back then.
But that's just a digression.