Parameters of EMA Compliance and Self-Reported Reactivity in a Longitudinal Study of Young Adult Cannabis and Tobacco Co-Users.

Background:Co-use of cannabis and tobacco has become increasingly popular among young adults. Interactive voice response (IVR) based ecological momentary assessment (EMA) allows for measurement of behavior in or near real-time, but has limitations including non-compliance, missing data, and potential for reactivity (e.g., behavior change) from frequent assessments. Methods:This study examined tobacco and cannabis use characteristics and factors associated with IVR compliance and self-reported reactivity in 97 young adults who reported cannabis and tobacco co-use at baseline and completed daily IVR surveys of co-use behavior at three random times per day for 28 days. Results:Overall IVR compliance was 55%, with a modal compliance of 60%. Compliance rates did not differ across morning, midday, and evening surveys, but significantly declined over time. The sample was divided into high frequency responders (>70% calls completed, n=35) and low frequency responders (<70%, calls completed n=62). There were no differences between high and low frequency responders on any baseline demographic, tobacco use (nicotine dependence severity), alcohol, or cannabis use characteristics (past 30-day frequency of use). Participants were receptive to IVR-based EMA monitoring and, 16.5% reported purposely decreasing nicotine/tobacco use due to monitoring, while 19.6% reported purposely decreasing cannabis use, which predicted lower cannabis use post-EMA monitoring. Conclusions:Real-time assessment of co-use behavior among young adults does not appear to be impacted by specific demographics or substance use severity (nicotine dependence, heavy drinking). Data suggest some predictive utility of IVR-based EMA monitoring on short-term behavior change. More intensive approaches are needed to improve compliance among young adult cannabis and tobacco co-users.