The Impact of Cannabis Use Disorder and its Treatment on Opioid-related Health Consequences: A Longitudinal Study of VA Patients - PROJECT SUMMARY/ABSTRACT Over 600,000 people have died from opioid-related overdoses in the United States (U.S.) since 1999, and rates of opioid-related hospitalizations, overdose, and opioid use disorder (OUD) remain high despite policy reforms aimed at reducing their public health burden. Alongside the ongoing opioid crisis, cannabis use has increased significantly, with 40 million adults using cannabis in 2022, 33% of whom will develop cannabis use disorder (CUD). Despite the negative health consequences of CUD, access to its treatment (i.e., non-pharmacologic interventions) remains limited. The ongoing opioid crisis coupled with a dramatic increase in cannabis use in recent decades has prompted research into whether cannabis use contributes to or mitigates opioid-related health risks. Although cannabis use may influence opioid use through various mechanisms, research examining the impact of CUD on opioid-related outcomes remains limited. No longitudinal studies have examined associations between CUD and OUD, opioid-related hospitalizations, and fatal or non-fatal overdoses, and whether receipt of CUD treatment reduces these risks. CUD substantially impacts patients who receive care in the Veterans Health Administration (VHA), one of the largest healthcare systems in the U.S. In the VHA, CUD prevalence has nearly quadrupled since 2005, and opioid-related hospitalizations and overdoses have increased. Our preliminary 2005-2022 data from ∼4.5 million VHA patients show increases in co-occurring CUD and OUD with an adjusted past-year prevalence of OUD that is markedly higher in patients with CUD (11.36%- 13.19%) than those without (0.72%-1.08%). From 2005-2020, the adjusted annual opioid-related mortality rate per 100,000 persons was also substantially higher in patients with CUD (42.0-180.53) than without CUD (18.9- 33.2 deaths), with a between-group disparity that widened over time. Given these initial results and growing concerns about the health risks of CUD, we propose a cohort study that leverages the size and scope of the VHA electronic health record (EHR) to 1) examine CUD as a risk factor of subsequent opioid-related health outcomes; 2) identify potential barriers and facilitators of non-pharmacologic interventions among patients with CUD and whether receipt of CUD treatment is associated with reduced risk of subsequent opioid-related outcomes, and 3) determine individual and state-level modifiers of these associations. These research aims are complemented by an outstanding interdisciplinary research team with extensive prior collaborations yielding high-impact research, and expertise in veteran health, SUDs and health services. By identifying CUD as a potential risk factor of opioid-related harms and establishing if engagement in CUD treatment may mitigate these risks, this research has important clinical and public health implications for the ongoing opioid crisis in the U.S. and will provide necessary information to clinicians, healthcare administrators, and policymakers on the opioid- related public health consequences of CUD and its treatment.
