Validation of a multisubstance online Timeline Followback assessment

Abstract

Objectives: The Timeline Followback (TLFB) was originally developed to assess alcohol consumption patterns (American Journal of Public Health, 86, 1996, 966) and has been increasingly modified for Web-based use. Additionally, new modes of substance use administration have emerged, creating a need for an adaptable TLFB tool than can capture data such as cannabis product potency or prescription drug use. Our goal was to validate an online TLFB that reliably assesses a wide range of substances in greater detail. Methods: Using a within-subjects counterbalanced design, daily substance use data were collected from 50 college students over a 14-day retrospective period using both the traditional in-person TLFB and online TLFB (O-TLFB). Results: All substance use variables, including detailed measures of cannabis metrics, correlated significantly (r's ranged from.653 to.944, p