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Validation of self-reported cannabis dose and potency: an ecological study
Peggy van der Pol1, Nienke Liebregts, Ron de Graaf
1Trimbos Institute, Netherlands Institute of Mental Health and Addiction, Utrecht, the Netherlands.
Addiction (Abingdon, England)
|May 1, 2013
Summary
Self-reported cannabis dose and potency measures show weak associations with objective data. However, estimating dose by joints per gram and using cannabis price or subjective potency offers some validity for frequent users.
Area of Science:
- Cannabis research
- Drug use epidemiology
- Substance use disorder
Background:
- Accurate quantification of cannabis use is crucial for research and clinical practice.
- Self-report measures are commonly used but their reliability and validity are often questionable.
- Understanding the discrepancies between self-reported and objective measures is vital for improving data quality.
Purpose of the Study:
- To evaluate the reliability and validity of self-reported cannabis dose and potency.
- To compare self-reported cannabis measures with objective assessments in frequent young adult users.
- To identify which self-report methods, if any, demonstrate reasonable accuracy.
Main Methods:
- A cross-sectional study involving 106 young adult frequent cannabis users.
- Comparison of self-reported cannabis amount and delta-9-tetrahydrocannabinol (THC) concentration with objective measurements.
- Assessments conducted in participants' homes or a coffee shop setting.
Main Results:
- Self-reported cannabis doses were imprecise; however, estimating dose by the number of joints made from 1 gram showed group-level accuracy.
- The prompt card method for dose estimation led to significant underestimation.
- Cannabis price and subjective potency were associated with objective THC concentration, but self-reported intoxication level was not.
Conclusions:
- Self-report measures for cannabis use exhibit limited association with objective data.
- Estimating the number of joints per gram, cannabis price, and subjective potency appear to be the most valid self-report indicators.
- Further research is needed to refine accurate methods for assessing cannabis consumption patterns.
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