Context: There are relatively few studies that address concurrent marijuana and prescription opioid use in populations over 50. The existing research primarily focuses on alternate substance use among adults engaging in marijuana use, and many studies focus on pain as the primary variable of interest. To our knowledge, less is known about demographic, socioeconomic, and psychiatric factors which increase likelihood of marijuana use in older patients who use prescription opioids.

Objective: To understand factors associated with concurrent prescription opioid and marijuana use among participants over 50

Design: Secondary survey data analysis using multinomial regression

Dataset: National Survey on Drug Use and Health Data (NSDUH)

Participants: Participants in the NSDUH (N=2797) data who are over 50 and who have been using prescription opioids for at least 1 year

Outcome measures: Frequency of marijuana use (no use, casual, moderate, and consistent)

Results: Older adults who are female (RRR=0.43, 95%CI=0.29, 0.62), married (RRR=0.53, 95%CI=0.36, 078), make more than $20K (RRR=0.59, 95%CI=0.37, 0.96), find it difficult to get marijuana (RRR=0.14, 95%CI=0.062, 0.30), and live in a state with with a medical marijuana law (RRR=0.57, 95%CI= 0.38, 0.85) are at lower risk for consistent use. Older adults were at higher risk when they had co-occurring substance use issues, including alcohol dependence (RRR=1.92, 95%CI 1.27, 2.90) and tobacco dependence (RRR=2.38, 95%CI= 2.35, 4.86). Moderate and casual users had similar differences when it came to co-existing substance use issues and access to marijuana but were generally younger. Moderate users tended to have lower levels of depression (RRR=0.33, 95% CI=0.17, 0.67).

Conclusions: Co-occurring substance use is associated with higher risk of casual, moderate and consistent marijuana use compared to no marijuana use among older adults who have been using prescription opioids for the past year. Primary Care Providers should consider patients who use marijuana and opioids concurrently to be at higher risk for other substance use disorders and should monitor them carefully. Although the NSDUH data provided strong generalizability, there were no measures of chronic pain and pain severity. Future studies should consider the interaction between pain, pain severity, and other factors which increase risk for concurrent use of marijuana and prescription opioids.