Factor structure of the modified timeline followback: A measure of alcohol-related consequences

Objective: Knowledge of the types of consequences as sessed by a given measure of alcohol-related consequences is important, as it may affect how the scores from that measure relate to individual differences and how the measure is used in treatment. This study was designed to examine the factor structure of the modified Timeline Followback (TLFB). Method: Undergraduate students (n = 573; 68.9% female) who drank alcohol at least once in the past 30 days completed an online version of the modified TLFB, a measure of alcohol use and alcohol-related consequences. Results: A confirmatory factor analysis supported the previously proposed four-factor structure of the consequences assessed by the modified TLFB (i.e., personal, social, role functioning, and physical consequences). Internal consistency of the four categories, as assessed by deleted-item odds ratios, was good. Additionally, correlations between subscale scores and measures of alcohol use provided evidence of convergent validity, and intraclass correlations between two administration formats (online vs. in-person) indicated preliminary concurrent validity of the four factors. Conclusions: Overall, this study found support for the factor structure that was previously proposed by Norberg et al. Both the results of the confirmatory factor analysis and the deleted-item odds ratios indicate that most items fit the model well. Four items, however, could not be included in the model as a result of either low endorsement or poor fit, suggesting that further research on these items is needed.