Trends in Detection Rates of Risky Marijuana Use in Colorado Health Care Settings

Abstract

ABSTRACT. Background: Over the past several years, many states, including Colorado, have approved medical marijuana legislation. There is concern that increased access to and visibility of medical marijuana may lead to harmful use. Methods: This study examined changes in patients’ marijuana use in 12 health care settings through a statewide screening, brief intervention, and referral to treatment (SBIRT) initiative. Results: Beginning in 2009, the odds of screening positive for risk-prone marijuana use significantly increased, coinciding with dramatic increases in use of Colorado's medical marijuana program. Young males were most likely to screen positive. Among users, there was a small, statistically significant increase in severity of use over time. Conclusions: Findings suggest that health care providers may be serving increasing numbers of patients using marijuana for medical or recreational perposes.

Keywords:

• Health care
• illicit substances
• marijuana use
• SBIRT

Acknowledgments

SBIRT Colorado is a statewide initiative of the Office of the Governor, funded by Substance Abuse and Mental Health Services Administration (5U79TIO18302-02), administered by the Colorado Department of Human Services, Office of Behavioral Health, and managed by Peer Assistance Services, Inc. (www.improvinghealthcolorado.org). The authors would like to thank Dr. Fred Pampel for his consultation on the statistical analyses.

Notes

To avoid having the vast majority of nonusers overwhelm the results on level of usage, we use regression only for those reporting some marijuana use. We also used zero-inflated negative binomial regression as a way to include the full sample while separating nonusage from severity of usage. Both methods give essentially the same results. However, because negative binomial regression is designed for count outcomes rather than for a scale, we report the regression results.