How Accurate Is Youth Self-Reporting of Substance Use?

Prevalence data regarding youth substance use have been derived primarily from self-reported survey responses. Objective biomarker data to corroborate such findings have been lacking.

To address this limitation, researchers analyzed data from 517 adolescents and young adults (aged 12–21 years) who completed an anonymous survey. They were asked questions about tobacco, e-cigarette, and marijuana use during the past week and provided a urine sample. Urinary biomarkers were measured, including cotinine to confirm nicotine use, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol to confirm tobacco use, and Δ9-tetrahydrocannabinolic acid (THCA) to confirm marijuana use.

Among participants, 2.9% reported using tobacco, 14.3% e-cigarettes, and 11.4% marijuana. Only 2% of those reporting nonuse of each substance had biomarker measurements above the specified detection levels, demonstrating a high degree of correlation between self-reported and biomarker data. However, 40% of those who reported using nicotine-free products had cotinine levels above the detection threshold, suggesting that many were unaware of the nicotine content of e-cigarettes. A high percentage (61%) of those with above-threshold cotinine levels also had above-threshold THCA levels, indicating a high degree of dual nicotine and marijuana use.