The ministry collects patient outcome data for ST-segment elevation myocardial infarction (STEMI) and stroke patients as a measurement for land ambulance performance. The data below shows the survival rate for these patient cohorts, who are transported by ambulance to an emergency department.  

ST-elevation myocardial infarction

ST-segment elevation myocardial infarction (STEMI) is a form of heart attack that can cause death if not treated quickly. footnote 1 A STEMI can be identified by a paramedic through evidence of myocardial damage visible on a 12-Lead ECG resulting in ST segment elevation. footnote 2

STEMI Mortality Rate for Ambulance Patients for


A stroke occurs when blood stops flowing to any part of your brain, damaging brain cells. The effects of a stroke depend on the part of the brain that was damaged, and the amount of damage done.footnote 3

Please select a year for stroke data.

Stroke Mortality Rate for

Mortality rate

The mortality rate is created by linking STEMI and stroke cohort data to Health Analytics Branch’s internal death file. The death file uses several administrative databases (Discharge Abstract Database, National Ambulatory Care Reporting System, Ontario Mental Health Reporting System, Continuing Care Reporting System, OHIP Claims, and Registered Person Database) to determine Ontario residents’ date of death.

The 30-day mortality rate includes STEMI and stroke patients who died within 30 days from the ED registration date. STEMI and stroke mortality rate for ambulance patients by region is reported on a 3-fiscal year combined basis ending March 31st of the previous year.

Risk adjustment factors

When comparing outcomes across regions or over time, it is important to account for differences in patient characteristics. Risk adjustment is a method used to control for patient characteristics that may affect health care outcomes and improves comparability after the pre-existing influence of patient population is removed. Therefore, risk adjustment allows for fair comparison of performance between the populations in different regions. The selected risk factors for STEMI and stroke were identified based on a literature review, clinical evidence and expert group consultations using the principles of appropriateness, viability (for example, enough events) and data availability.

The risk adjustments for the STEMI 30-day mortality rate control for:

  • fiscal year
  • quarter
  • age
  • sex
  • Charlson Comorbidity Index
  • previous inpatient admissions
  • shock
  • diabetes with complications
  • congestive heart failure
  • cancer
  • cerebrovascular disease
  • renal failure
  • arrival by ambulance

The risk adjustments for the stroke 30-day mortality rate control for:

  • fiscal year
  • quarter
  • age
  • sex
  • Charlson Comorbidity Index
  • stroke type
  • previous inpatient admissions
  • atrial fibrillation
  • previous stroke/TIA
  • history of coronary artery disease
  • diabetes
  • peripheral vascular disease
  • hypertension and hyperlipidemia following an Emergency Department Visit for Stroke

Confidence limit

A confidence interval (CI) reflects the uncertainty surrounding the risk-adjusted mortality ratio. The narrower a CI, the more one can be confident in the value of the risk-adjusted mortality ratio. The data presented here shows a 95% confidence interval of the risk-adjusted mortality ratio.

Reporting period

Is based on three years of pooled data. The data is updated annually to show the previous 3 fiscal years.

For more information, please contact the Health Analytics Branch by email.