Assessing Past-Month Substance Use in Emerging Adults: Consistency Between Timeline Followback and Monthly Surveys...

Area of Science:

• Adolescent development
• Substance use research
• Psychometric evaluation

Background:

• Accurate measurement of adolescent substance use is crucial for understanding developmental risks.
• The consistency of common self-report methods for substance use among adolescents and young adults requires further investigation.

Purpose of the Study:

• To compare the consistency of past 30-day substance use self-report data (alcohol, cannabis, nicotine) between timeline follow-back interviews and monthly retrospective surveys.
• To assess the concurrent validity of these self-report modalities with measures of substance use consequences, craving, and use disorder symptoms.

Main Methods:

• Ninety-four participants (19-21 years old, 62% female) from a longitudinal study were assessed.
• Substance use was measured using in-person timeline follow-back interviews and mobile monthly retrospective surveys.
• Reliability and concurrent validity between modalities were analyzed for alcohol, cannabis, and nicotine use.

Main Results:

• Alcohol (ICC=0.91) and cannabis (ICC=0.88) use showed excellent and good agreement between survey modalities, respectively.
• Nicotine use exhibited poor agreement (ICC=0.30) between the in-person and mobile survey methods.
• Concurrent validity differed for cannabis symptoms and problem outcomes between modalities, but was comparable for alcohol and nicotine.

Conclusions:

• Self-report consistency for adolescent substance use varies by substance, with significant differences observed for nicotine and cannabis.
• While alcohol use reporting was consistent, nuances in measurement considerations are important for cannabis and nicotine in longitudinal studies.
• Findings inform strategies for maintaining reporting accuracy while reducing participant burden in studies of young people.