Cannabis-Related Hospitalizations and Emergency Department Visits at a Glance

Release date: December 2018

Data sources

Hospitalization and ED visit data are collected by the Canadian Institute for Health Information (CIHI) on a fiscal year basis. For hospital visits, the main diagnostic code is the “most responsible diagnosis” (MRD) that is deemed to be the clinically significant reason for the visit. For ED visits, the main diagnostic code is the “main problem” (MP). Hospitalization and ED visit data provide only a crude measure of the burden of cannabis use. Data are influenced by factors that are unrelated to health status such as availability and accessibility of care, administrative policies and hospital procedures. This may influence comparisons between areas and over time.

For all indicators, data were analyzed by the residence of the patient, not where the hospitalization or ED visit occurred. Ontario residents treated outside of the province were excluded. Data were reported by calendar year, based on the year of the hospitalization or ED visit. This report includes hospitalization and ED visit indicators with relevance to public health programming.

Cannabis-related hospitalizations and ED visits were selected using ICD-10-CA codes T40 (.7) (i.e., poisoning) and F12 (.0-.9) (i.e., mental and behavioural disorders due to acute intoxication, harmful use, dependence, etc. from the use of cannabinoids) whether it was the MRD/MP or comorbidity. This excludes injuries such as from motor vehicle traffic crashes or chronic conditions such as cancer where cannabis may be a contributing factor. Hospitalizations to designated adult mental health hospital beds were not included in this analysis. ED visits where the health care provider documented uncertainty in the diagnosis (diagnosis prefix Q) and ED visits that resulted in a transfer to another ambulatory care facility were included in the counts. Hospitalization and ED visits for mental and behavioural disorders due to multiple drug use (F19) were excluded. Multiple codes can exist for each hospitalization or ED visit. As such, a unique visit number, DAD key (hospitalizations) or NACRS key (ED visits), was used to count the number of hospitalizations or visits where at least one of the above codes was captured as the MRD/MP or comorbidity. In Figure 5, there is no distinction between prescription and illegal cannabis use.