February 2020

In This Issue: Advancements in VA Primary Care
» Table of Contents

Cannabis Use and Health among VHA Primary Care Patients

Feature Article

Takeaway: This project is the first to characterize and understand patterns of cannabis use among VA primary care patients – and how cannabis use relates to health, functioning, and the use of healthcare services. Further, this project will help inform the discussion regarding for whom and under what conditions cannabis use might be associated with fewer or greater negative outcomes.

Cannabis use has been linked to adverse physical, mental health, and social outcomes. Such consequences may be even more pronounced among certain population subgroups, including those with psychiatric illnesses, which are overrepresented in the VA patient population. Despite potential harms, some patients who use cannabis report that it is beneficial for the management of chronic pain, PTSD, and other illnesses. Although more than one million Veterans regularly use cannabis (i.e., have used cannabis within the past month), only limited research has investigated cannabis use among patients in the VA healthcare system. Additional research is needed to characterize and understand patterns of cannabis use and how they relate to health, functioning, and service utilization among VA primary care patients. 

This ongoing HSR&D study (May 2017 – April 2021) will:

• Characterize cannabis use among a representative sample of VA primary care patients;
• Examine the extent to which cannabis use is associated with psychoactive medication use (e.g., opiates and other psychotropics), substance use, substance use disorder symptoms, mental health symptoms (e.g., PTSD), pain, functioning, and treatment utilization among patients with regular cannabis use and those with no past-year use;
• Identify cannabis use and cannabis use disorder symptom trajectories at 6 and 12 months following an initial primary care visit; and
• Longitudinally estimate associations between cannabis trajectory groups and substance use, substance use disorder symptoms, mental health symptoms (e.g., PTSD), pain, functioning, and treatment utilization.

This study will screen Veterans receiving primary care at three VA medical centers in Michigan. Through in-depth screening, investigators will identify a cohort of patients with regular cannabis use, defined as having at least monthly use during the past year. The cohort with regular cannabis use will complete an in-depth baseline interview as well as 6- and 12-month follow-up assessments to identify cannabis use and cannabis use disorder symptom trajectories, and examine related health, functioning, and service utilization outcomes.

Preliminary Findings

Data collection is ongoing. It is expected that this study will characterize patients who do and do not use cannabis, as well as identify key patient subgroups that have higher cannabis-related health risks and might benefit from additional intervention and treatment efforts to address this excess risk.

Impact

This project is the first to characterize and understand patterns of cannabis use among VA primary care patients and how cannabis use relates to health, functioning, and service use. The focus on trajectories of cannabis use and related problems is important; in characterizing and examining factors associated with these trajectories, the project will help inform the discussion regarding for whom and under what conditions cannabis use might be associated with fewer or greater negative outcomes.

Principal Investigator: Kipling Bohnert, PhD, is part of HSR&D’s Center for Clinical Management Research (CCMR) in Ann Arbor, MI.

Publications

Davis A, Lin L, Ilgen M, and Bohnert K. Recent cannabis use among Veterans in the United States: Results from a national sample. Addictive Behaviors. January 2018;76:223-228.

View study abstract