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Leveraging Social Media to Develop the Cannabis Exposure Index (CEI), A Standardized Measure of Cannabis Use

Funding Source

NIDA, R01DA050032

Project Period

9/30/2020 – 7/31/2025

Principal Investigator

Alan J. Budney, PhD (Geisel School of Medicine at Dartmouth)

Other Project Staff

Deborah Hasin, PhD (Columbia University) (Multiple PI); Jacob T. Borodovsky, PhD (Geisel School of Medicine at Dartmouth) (Co-I); Mohammad Habib, BA (Geisel School of Medicine at Dartmouth) (Research Assistant)

Project Summary

Americans increasingly believe cannabis to be a harmless substance with therapeutic benefits; cannabis is increasingly legal in the U.S.; a burgeoning industry has introduced novel and high potency products; and the prevalence of use and cannabis use disorder (CUD) has increased. The scientific and public health communities have struggled to keep pace in determining the impact of this changing cannabis landscape. An important barrier to progress is the lack of an adequate measure of cannabis consumption. Unlike measures of alcohol use that can discriminate high and low risk drinking patterns, current cannabis measures are inadequate to investigate cannabis risks and benefits, the impact of policy changes, and the outcomes of clinical trials. Developing valid measures faces multiple challenges, including estimation of quantity, and data collected from sufficiently large and diverse samples to validate indicators of differential cannabis exposures. Leveraging our expertise in clinical cannabis research, CUD diagnostics, measure development, and social media survey methods, we propose to address these challenges via a rigorous mixed-methods study to develop and test a family of measures of cannabis exposure: The Cannabis Exposure Inventory (CEI; timeframe, past 30 days), a short form (CEI-S), and a daily form (CEI-D; timeframe, last 24 hours). Aim 1: Prepare initial CEI. Our expert team will assemble and program an initial version of the CEI using novel items and images to estimate use. Through cognitive interviewing and a developmental test-retest study, we will examine how users understand the questions and response categories, and iteratively adjust the CEI. Aim 2: Initial examination of CEI validity. We will administer an on-line survey with the CEI, validators (e.g., CUD severity) and covariates to 3,000 cannabis users recruited via well-tested social media survey methods and research panels. Psychometric analyses and a definitive test-retest reliability study (n=600) will assess associations between the different exposure item domains (construct validity) and identify the combination of items most associated with external validators (convergent validity) to inform further refinement of the CEI. Aim 3: Confirm CEI validity in a large sample of current users; develop the CEI-S. We will administer the CEI to 12,000 users to confirm construct and convergent validity, overall and across major subgroups (e.g., gender, age, race/ethnicity). We will derive the CEI-S for use in studies where time does not permit the full CEI. Aim 4: Prepare and validate the CEI-D. We will create the CEI-D, adjusting the CEI-S timeframe to the prior 24 hours for use as a daily measure and examine its validity. A subsample from Aim 3 (n=400) will complete the CEI-D and report on functioning and mood for 30 days on a mobile device. Consistent with FDA guidelines on demonstrating validity of outcome measures, we will test how change over time in the CEI-D tracks with change in functioning and mood. Accomplishing these aims will provide the field with a set of greatly improved measures of cannabis use that will enhance clinical and epidemiologic research, and lead to more informed communication about cannabis to clinicians, health educators and policy makers.

Public Health Relevance

The scientific community has struggled to keep pace with the impact of the changing landscape of cannabis use and policy in the U.S. An important barrier to progress is the lack of adequate measures of cannabis consumption that can be used to identify low vs. high risk use patterns. We propose to address this challenge via a rigorous cannabis measure development / validation project that will enhance the capacities of clinical, epidemiologic and policy studies and lead to more informed communication about cannabis and its risks to clinicians, health educators and policy makers.