Patterns of Hospital Utilization Related to Cannabis Use in the United States: 2004 to 2011

Background: Cannabis is the most widely used illicit drug in the United States. According to the National Survey on Drug Use and Health, the number of users reached 18.9 million in 2012, and 7.6 million of them consumed cannabis almost every day. This increasing prevalence, coupled with legalization initiatives in several states, has intensified the debate over the societal impact of cannabis use. The objective of this study is to examine the pattern of cannabis-related hospital utilization.

Methods: Data come from the Drug Abuse Warning Network (DAWN), which is the only nationwide data collection system to monitor drug misuse and abuse related emergency department (ED) visits. This study focused on patients aged 12 years and older, who were admitted to an ED with cannabis involvement from 2004 to 2011. The outcomes of health service utilization were categorized as ED treated and released, inpatient admission and other dispositions. The predictors included gender, age, race/ethnicity, time of visit, and type of case admission (such as suicide and adverse reaction). The trends over time for each service utilization outcome were calculated, and logistic regression was used to estimate the odds of hospitalization for cannabis users visiting the ED.

Results: From 2004 to 2011, cannabis-related ED visits increased 70% from 281,218 to 479,021, and 23.1% of the total ED patients were admitted into inpatient cares. Cannabis-only users accounted for 43% of the ED admission increase, and increased 70% inpatient admissions from 2006 to 2011. All subcategories of inpatient utilization showed the general rising trends except the detox or psychiatric care for cannabis-only users. Logistic regression results indicated that cannabis-only users aged 30 to 44 had 2.8 times the odds of hospitalization compared to users aged less than 21. Use of cannabis concurrent with other drugs also increased the likelihood of hospitalization (OR: 1.27; 95% CI: 1.14-1.42).

Conclusion: Our findings suggest that there is a significant and increasing prevalence of cannabis-related ED visits and inpatient admissions in the United States, especially for cannabis-only users. Our study has important implications for hospital providers in states experiencing increasing prevalence of cannabis use.