Abstract
OBJECTIVES: Timeline follow-back (TLFB) is a self-report measure commonly used as a method of assessing historical drug use in both clinical and research settings. Our study considered rates of agreement between TLFB and an objective biological assay of opioid use. METHODS: We calculated the rates of agreement between negative report of opioid use for the most recent 8 days on TLFB and urine toxicology (UTOX) results in a large multisite opioid use disorder treatment trial. RESULTS: In total, 3986 assessments were provided by trial participants with both UTOX and TLFB during weeks 1 to 12, 2716 during weeks 13 to 24, and 325 at week 28. Rates of disagreement between negative TLFB and positive opioid UTOX were 2.33% of all assessments (21.68% of those with positive UTOX) over weeks 1 to 12, 2.06% of all assessment (25.00% of those with positive UTOX) over weeks 13 to 24, and 9.85% of all assessments (26.02% of those with positive UTOX) at week 28. CONCLUSIONS: Negative TLFB seems to be generally associated with negative results on urine toxicology.