Biologic testing for THC
Participants will be asked to complete at-home urine test(s) and a series of oral fluid tests.
Loading study record…
Loading study record…
The purpose of this study is to identify and evaluate oral fluid testing as a biologic measure of cannabis use days that can be assessed remotely. The researchers will conduct this fully virtual study among a community sample of 200 individuals aged 18-30 years who have used cannabis at least 1 time per week on average in the past 30 days. Participants will complete oral fluid (saliva) tests, urine tests, and Timeline Follow-back interviews (self-report) that indicate their recent cannabis use (delta-9-THC). Participants will present for 3 virtual study visits across \~3-4 weeks and be asked to complete activities in between: Study Visit 1 (Day 0; informed consent, baseline survey, TLFB interview), Study Visit 2 (\~Day 7; TLFB interview, urine testing), 6 days of at-home videorecorded oral fluid testing, Study Visit 3 (\~Day 21; TLFB interview, urine test, oral fluid test, survey, interview).
Locally preserved from ClinicalTrials.govOpen ClinicalTrials.govlast source update 2026-09-15
What this record can show
This locally preserved record separates the registered protocol from source-reported registry results. Neither is a treatment recommendation.
Registry facts
Linked local records
Local links use governed condition terms or exact source-reported intervention names. They are navigation candidates, not efficacy claims.
Interventions
Participants will be asked to complete at-home urine test(s) and a series of oral fluid tests.
Eligibility
Community sample
primary outcomes
Time frame: Across 6 days leading up to the Day-21 visit
Duration in minutes of videos of self-testing
Time frame: Day of/During the Day-21 visit
Duration in minutes of observed self-testing during study visit
Time frame: Across 6 days leading up to the Day-21 visit
Number and percent of videos of self-testing completed
Time frame: Day of/During the Day-21 visit
Number and percent of live self-testing completed
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Number and percent of each step of self-testing performed (yes/no)
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Number and percent of each step of self-testing performed correctly (yes/no)
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Number and percent of oral fluid tests with unreadable results
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Number and percent of oral fluid tests with inconclusive results
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Oral fluid test results for delta-9- tetrahydrocannabinol (delta-9-THC) on day of test (negative = non-use / positive = use)
Time frame: Day-21 visit
Measure of acceptability (usability, likability, burden), 5 items, 5-point Likert-type scale (1, Strongly Disagree to 5, Strongly Agree), with higher score indicating greater acceptability. Benchmark for scale: ≥80% of participants with mean item score ≥4 out of 5
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Agreement between oral fluid results for 3 consecutive days (any positive = use / all negative = non-use) and self-report on timeline follow-back (TLFB) calendar interview for the same 3 days plus 1 day earlier (any days of use = use / no days of use = non-use). Benchmark: ≥ moderate agreement (Cohen's kappa ≥ 0.6)
Time frame: Day-21 visit
Agreement between oral fluid test results (positive/negative) and urine test result (positive/negative). Benchmarks: strong agreement (Cohen's kappa ≥ 0.8) for use; weak agreement (Cohen's kappa \< 0.6) for non-use
secondary outcomes
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Agreement (use/non-use) between oral fluid test results and cannabis use reported on TLFB calendar interview for corresponding intervals ranging from 2 days (day of and day before testing, ≤24 hours prior) to 8 days
other outcomes
Time frame: Day-21 visit
Number of times cannabis used within each day included in the intervals being examined for agreement (Specific Aim 2A and 2B), reported on TLFB calendar interview
Time frame: Across 6 days leading up to the Day-21 visit; Day of/During the Day-21 visit
Number of hours between last use and oral fluid testing time
Publications
No exact PMID-linked public article is currently readable locally.