Trends and Outcomes of Cannabis Use Disorder Among Adolescents Hospitalizations with Asthma

Background: Cannabis use is on the rise due to its popularity and changes in the legislation regulating its use. Recent studies have shown an association between inhalation of cannabis and worsening of asthma symptoms. There are no population-based studies available to estimate the burden and outcomes of cannabis use disorder (CUD) among asthma hospitalizations. Our objective was to examine the trends and short-term outcomes of cannabis use among adolescents with asthma-related hospitalizations in the United States (US) from 2009-2017.

Methods: This was a serial cross-sectional analysis of asthma-related hospitalizations among adolescents aged 12-18 years within the National Inpatient Sample from 2008-2017. Hospitalizations due to asthma and CUD were identified using previously validated International Classification of Diseases (ICD-9 and ICD-10) diagnostic codes. The outcomes of interest were the trends in the proportion of asthma-related hospitalizations with CUD, need for mechanical ventilation, length of stay, and mortality. Bivariate analysis and Chi-square were used to compare those with and without CUD. Multivariable survey logistic regression was used to analyze temporal trends, predictors, and outcomes of CUD among asthma hospitalizations. P-value <0.05 was considered significant.

Results: Out of a total 142,913 hospitalizations due to Asthma in adolescents, 5,723 (4%) had concurrent CUD. Proportion of patients using cannabis increased from 2.0 % in 2007 to 7.7% in 2018 (Figure 1) with an average yearly increase of 11% [adjusted odds ratio (aOR) 1.11, 95%confidence interval (CI) 1.08-1.14; P<0.001)] adjusted analysis (Table 1). Asthma hospitalizations with concurrent cannabis use were more likely to be 16-18 years of age (84.2%), male (57.7%) and of African American race (43.7%). Furthermore, cannabis use was associated with higher rates of non-invasive ventilation (5.5% vs 3.2%, P<0.01) and invasive mechanical ventilation (4.0% vs 1.8%, P<0.01). In multivariable logistic regression, age group 16-18 years (aOR 4.564; 95% CI 3.50-5.95; P< 0.0001), male gender (OR 1.998; 95% CI 1.64-2.43; P<0.0001), and the West census region (OR 1.41; 95% CI 1.07-1.85; P<0.015) were associated with higher odds of CUD. After adjusting for confounding factors, CUD had no significant impact on length of hospital stay or in-hospital mortality.

Conclusion: Cannabis use disorder among adolescents with asthma hospitalizations increased between 2008 and 2017. The association of male gender and age 16-18 years with CUD suggests that counseling against cannabis use must begin in the early adolescent period. Further surveillance and additional research are needed to determine the impact of cannabis use on the severity and control of asthma and healthcare resource use