Emergency Room (ER) visit data are part of the Ambulatory Visit Database, obtained from the National Ambulatory Care Reporting System (NACRS) developed by the Canadian Institute for Health Information (CIHI) and the Ministry of Health and Long-Term Care of Ontario (MOHLTC).
The system collects patient level data on visits to hospital ambulatory services, in this case, emergency rooms. The data represent the number of ER visits, not the number of people visiting the ER.