The timeline followback reports of psychoactive substance use by drug-abusing patients: Psychometric properties

The Timeline Followback (TLFB; L. C. Sobell & M. B. Sobell, 1996) interview , which uses a calendar method developed to evaluate daily patterns and fre quency of drinking behavior over a specified time period, has well-establis hed reliability and validity for assessing alcohol consumption. Although se veral investigators have used the TLFB to evaluate drug-using behavior, few studies have examined the psychometric properties of the interview for thi s purpose. The authors conducted TLFB interviews with a sample of adult dru g-abusing patients seeking treatment for substance abuse (n = 113) at basel ine, posttreatment, and quarterly thereafter for 12 months. It was found th at the patients' reports about their drug consumption using this method gen erally had high (a) retest reliability, (b) convergent and discriminant val idity with other measures, (c) agreement with collateral informants' report s of patients' substance use, and (d) agreement with results from patients' urine assays.