Repeated Assessment of Alcohol Use and Perceived Norms Among College Students Who Drink: Comparisons to a Minimal Assessment at 12-Month Follow-Up

Objective: Clinical trials assessing efficacy of alcohol use interventions often aim to test differences between treatment and control conditions at several follow-up time points, requiring repeated assessment of outcomes (e.g., weekly number of drinks). There has been concern that repeated assessment may elicit assessment reactivity in which participants, even those who did not receive treatment, reduce their alcohol use, but findings in the literature have been mixed. The current study of assessment reactivity compared two control conditions that were part of a larger randomized controlled trial: (a) repeated assessment that completed surveys at baseline, 3-, 6-, and 12-month follow-ups, and (b) minimal assessment that only completed surveys at baseline and 12-month follow-up. Outcomes assessed at 12-month follow-up included (a) changes in alcohol use behavior and negative consequences, (b) changes in perceived descriptive and injunctive norms, and (c) participant attrition/retention. Method: Participants were undergraduate students who reported at least one heavy drinking occasion (4+/5+ drinks for women/men) in the past month (N = 456; 63.3% female; mean age = 20.11 years). Results: Multiple regression models indicated no significant differences between the repeated and minimal assessment control conditions on any indices of alcohol use (p values ranged from.42 to.97), negative consequences (p =.39), or on perceived descriptive/injunctive norms (p =.60 and.23, respectively). Attrition at 12-month follow-up was low in both groups, but significantly higher (p =.006) in the repeated assessment condition (16.49%) than the minimal assessment condition (8.55%). Conclusions: Repeated assessment did not elicit changes in alcohol use, negative consequences, or perceived norms. A minimal assessment control condition may not be necessary when assessing intervention efficacy across longitudinal follow-ups. However, when attrition at 12-month follow-up is a salient concern, a minimal assessment control may retain more participants than repeated assessment.