The university-wide Spit for Science survey was conducted early in the fall semester, with a follow-up survey approximately six months later in the spring semester (for all students who completed the initial survey, including the prevention program participants). To determine whether changes in alcohol use across time could be attributed to the prevention programs, we selected a set of control individuals from this parent Spit for Science study who did not participate in the prevention programs. Following completion of the spring follow-up, we retrospectively selected control participants who had completed both the fall and spring Spit for Science surveys, and matched them to the prevention study participants using the protocol described above (i.e. based on ethnicity, drinking behaviors, etc.). We then compared the controls’ changes in alcohol use across time to that of participants enrolled in the prevention programs.
