Why is an alcohol survey so concerned about sexual habits and living arrangements?
I tend to believe that these studies are corrupting in and of themselves. When my wife was a student in college, she went to the Student Health Center due to an illness. The Health Center had her fill out a very detailed survey about all kinds of sexual activity. She said she was embarrassed by the questions but had to complete the survey before being treated.
Alcohol consumption and sexual activity are directly proportional among college students. If they're not using condoms, it's probably because they're too inebriated to be able to get the package opened.