Development and initial validation of the alcohol-induced blackout measure

Abstract Background Blackouts are common among young adults and predict alcohol-related harm. However, existing measures do not capture the range of alcohol-induced memory impairment involved in blackout experiences and do not differentiate between fragmentary and en bloc blackouts. This study aimed to develop and validate a brief, reliable measure of alcohol-induced blackouts among young adults. Methods College students reporting alcohol-induced memory impairment in the past year were recruited via Qualtrics to participate in an online survey (N = 350, 56% female). A subsample (n = 109, 67% female) completed a one-month follow-up. Principal component analysis was used to determine the structure of the Alcohol-Induced Blackout Measure (ABOM), which was designed to reflect two components (fragmentary and en bloc blackouts). The reliability and validity of the total ABOM score was assessed. Results The final five items fit in a two-component scale structure; however, a single principal component accounted for 73% of variance in blackout items, all of which demonstrated high component loadings and communalities. The total blackout score demonstrated strong internal consistency, test-retest reliability, and convergent and incremental validity. ABOM scores predicted alcohol-related consequences at baseline and one-month follow-up. Conclusions The ABOM is a brief and reliable, self-report measure that quantifies the frequency of a range of blackout experiences in the past 30 days. Accounting for this range of experiences improved predictive validity over single-item blackout measures. Blackout frequency is a strong, unique predictor of alcohol-related problems.