Screening in Primary Care Settings for Illicit Drug Use: Assessment of Screening Instruments: A Supplemental Evidence Update for the U.S. Preventive Services Task Force [Internet]

Excerpt

Two approaches have been proposed for identifying illicit drug use and drug abuse among patients seen in routine clinical encounters: toxicologic tests of blood or urine, and standardized screening questionnaires. This report focuses only on the second approach. While toxicologic testing can provide objective evidence of drug use, false-positive results due to cross-reactions, contamination, or mislabeled specimens are always possible. More importantly, these tests do not distinguish between occasional users and individuals who are dependent on or otherwise impaired by drug use.