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Evaluate Your Drug Consumption

User Information


TLFB Drug, Cigarette, and Marijuana

Author/Developer :

Sobell, L. C., Sobell, M. B., Buchan, G., Cleland, P. A., Fedoroff, I., & Leo, G. I. (1996 November). The reliability of the Timeline Followback method applied to drug, cigarette, and cannabis use. Presented at the 30th Annual Meeting of the Association for Advancement of Behavior Therapy. New York, NY.

Sobell, Linda C. & Sobell, Mark B.
Center for Psychological Studies
Nova Southeastern University
3301 College Ave.
Ft. Lauderdale,
FL. 33314

Publication dates:


Description / Type of Assessment:

The TLFB is a method to assess recent cigarette, marijuana, and other drug use. The TLFB can be administered by an interviewer, self-administered, or administered by computer It involves asking clients to retrospectively estimate their drug, marijuana or cigarette use 7 days to 2 years prior to the interview date. For cigarettes and marijuana, individuals are asked to estimate the number of cigarettes or joints smoked per day. For all other drug use, only frequency of use is captured (i.e., used or did not use). At this time, quantity estimates of other drug use are not meaningful.

Primary use / Purpose:

Assessment (pre- and post-intervention) of cigarette, marijuana, and other drug use.

Domains measured / Life Areas / Problems Assessed:

Quantitative estimations of cigarette, marijuana, and other drug use.


Males and females ages 14 years and older in the general population and clinical samples

Administration / Completion Time:

10-30 minutes to complete, depending on the time period

Scoring Procedures:

The TLFB provides a variety of variables and different ways of reporting individual use levels.

Scoring Time:

Not applicable.


Minimum training is necessary.

Relevant Studies
Dr Linda C. Sobell, Dr Mark B. Sobell. No single review of the Timeline Followback Method (TLFB) for assessing marijuana, cigarette and other drug use has appeared to date. Individual studies documenting this method include: Brown, R. A., Burgess, E. S., Sales, S. D., Evans, D. M., & Miller, I. W. (1998). Reliability and validity of a smoking Timeline Follow-Back interview. Psychology of Addictive Behaviors, 12, 101-112; Ehrman, R. N. & Robbins, S. J. (1994). Reliability and validity of 6-month timeline reports of cocaine and heroin use in a methadone population. Journal of Consulting and Clinical Psychology, 62, 843-850; Gariti, P. W., Alterman, A. I., Ehrman, R. N., & Pettinati, H. M. (1998). Reliability and validity of the aggregate method of determining number of cigarettes smoked per day. American Journal of Addictions, 7, 283-287; Hersh, D., Mulgrew, C. L., VanKirk, J., & Kranzler, H. R. (1999). The validity of self-reported cocaine use in two groups of cocaine abusers. Journal of Consulting and Clinical Psychology, 67, 37-42; Midanik, L. T., Hines, A. M., Barrett, D. C. et al. (1998). Self-reports of alcohol use, drug use and sexual behavior: Expanding the timeline follow-back technique. Journal of Studies on Alcohol, 59, 681-689; Sobell, L. C., Sobell, M. B., Buchan, G. et al. (1996 November). The reliability of the Timeline Followback method applied to drug, cigarette, and cannabis use. Poster presented at the 30th Annual Meeting of the Association for Advancement of Behavior Therapy, New York, NY; Walton, M. A., Castro, F. G., & Barrington, E. H. (1994). The role of attributions in abstinence, lapse, and relapse following substance abuse treatment. Addictive Behaviors, 19, 319-330.

Data derived from a timeline method for assessing recent reports of marijuana, cigarette, and other drug use have been found to have high test-retest reliability. It has been evaluated with males and female drug abusers 14 years of afe and older. Originally developed for assessing alcohol use, the TLFB was extended to individuals who use other drugs, cigarettes, and marijuana. For marijuana, cigarettes, and other drugs, it has been psychometrically evaluated by the authors and several other investigators in several recent publications. (See references above)

Evidence for the method's validity derives mainly from clinical populations. TLFB self-reports of drug, marijuana, and cigarette use have typically been validated using, (1) measures of drug-related problems, (3) collateral informants' reports of the subjects' cigarette use; (3) urine tests; and (6) nicotine assays.

(1) Biochemical studies have found that reports of drug and nicotine use and biochemical tests of drug use (urine tests and hair assays) and nicotine levels (saliva cotinine) are related to drug and nicotine use, respectively, as reported on the TLFB.

(2) Correlations between TLFB drug use data and scores on the Leeds Dependence Questionnaire (LDQ) provide evidence for the validity of the TLFB method.

(3) Positive correlations have also been found in clinical studies that compared client and collateral reports of the clients' cigarette use

Page last updated: Wednesday, 14 July 2004