Asthma Mapper

Please upgrade your browser.

We built Asthma Mapper using the latest technologies. This makes Asthma Mapper faster, more secure, and easier to use.  Unfortunately, your browser doesn't support these technologies.  Please download one of these great browsers, and you'll be on your way.

Internet Explorer
Version 10+
Google Chrome
Version 40+
Mozilla Firefox
Version 34+
KFLA Public Health Informatics KFLA Public Health

Asthma Mapper
A tool to help manage asthma

Asthma Activity Trends in Ontario

Weekly Asthma Activity Level Indicator is determined by data reported to the Acute Care Enhanced Surveillance (ACES) System, supported by the Ministry of Health and Long Term Care based at KFL&A Public Health.

The Asthma Mapper website is currently undergoing a review. Weekly activity level's will therefore be unavailable until further notice.

Acute Care Sector Projections

Are based on:

  • emergency department visit volume for asthma, and
  • for a list of health unit and hospital partners, please view the ACES Hospital List (PDF).

Are influenced by:

  • circulating levels of respiratory viruses including rhinovirus and influenza,
  • environmental factors including heat, air quality, and weather events such as storms, and
  • exposure to triggers such as plant pollens, pet dander or tobacco smoke.

Map of Asthma Activity in Local Health Integration Networks

This map is not compliant with the Accessibility for Ontarians Act (AODA) because the technology does not exist to make the map compliant.  Please contact KFL&A Public Health Knowledge Management at 613-549-1232 for an alternate format.
  • +
    Hospitals on ACES
    Hospitals not on ACES
  • -
    LHIN (Local Health Integration Networks) Boundaries
  • Map marker ball right chartreuse icon legend image
    AQHI (Air Quality Health Index) Sensors
  • Lenged image for Alerts
    Southern Ontario Weather Alerts

Asthma Mapper Overview

The Asthma Mapper is a digital tool that uses real-time trends in asthma-related visits to the emergency rooms of participating Ontario hospitals.  Asthma Mapper is an interactive tool: users can "toggle" on and off additional layers of information about potential irritants (i.e. air quality or weather conditions), or can look at historic trends in asthma activity.  There are also a series of asthma-related resources available through Asthma Mapper, including links to evidence-based educational and management tools.

Asthma Mapper can act as an early warning system to help users better determine when an asthma management plan may need adjustment to help better control symptoms.  The tool can be useful for persons with asthma, their family or caregivers, and healthcare professionals.

The colours in Asthma Mapper represent weekly asthma attack levels, based on asthma-related presentations to participating hospitals within each Local Health Integration Network (LHIN) in Ontario.  The system describes activity levels according to a green, yellow, and red colour scheme.  

  • Click individual LHINs on the map to see total real-time asthma emergency department visits in each jurisdiction.  
  • Click on the resources tab for trusted asthma related education and information.  
  • For more information regarding the real-time data capture system used, see the ACES system briefing note.

**Note: Asthma Mapper is not a substitute for assessment by a medical professional for anyone experiencing respiratory distress.**

Individual Analysis on Asthma Related Illness in Ontario for this Week

Colour Risk Level Notes
Green Low Good opportunity to keep an up to date asthma management plan.
Yellow Moderate Individuals should take more notice when following their asthma management plan.
Red High Individuals should be vigilant when following their asthma management plan.

Asthmatics should also continue to manage their asthma by:

If your asthma begins to worsen, follow your asthma management plan as written by your doctor.  

In case of an emergency, dial 911 for immediate assistance.

Parents with children who suffer from asthma are also encouraged to communicate with schools and child care facilities to ensure that they understand the newly passed Ryan's Law and that their children are receiving appropriate asthma treatment.

For more information, visit the Ontario Lung Association webpage or call The Lung Association's Asthma Action Helpline: 1-888-344-LUNG (5864) for assistance.

Population Analysis on Asthma Related Illness Expectations in Ontario for this Week

Colour On a Population Level Impact on the Acute Care Sector % of E.D. Asthma Related Visits
Green Not Significant No significant impact < 2%
Yellow Increase as part of (or decrease from) a seasonal peak in activity Increased volume to Emergency Departments may be noted Organisations/schools may see increased for staff/student absenteeism rates Potential residual effects of high admission rates post-peak. 2-2.5%
Red Peak levels of activity are anticipated Significant impacts on Emergency Departments may be noted. Potential for increased rates of admission for asthma-related illness Organisations/schools may see increased for staff/student absenteeism rates. > 2.5%
E.D. - Emergency Department

Contact the ministry for more information about prevention, preparedness and response activities by email at or phone at 1-866-212-2272.

Individual Local Health Integration Network Colour Coding Cut-Offs (Asthma ER Visits as a Percentage of all ER Visits)

Region Green (%) Yellow (%) Red (%)
Erie St. Claire < 2 2 - 2.5 > 2.5
* South West < 2 1.35 - 1.75 > 1.75
*** Waterloo Wellington n/a n/a n/a
* Hamilton Niagara < 2.1 2.1 - 2.5 > 2.5
Central West < 2.75 2.75 - 3.75 > 3.75
Mississauga Halton < 2.3 2.3 - 2.75 > 2.75
** Toronto Central < 2 2 - 2.5 > 2.5
Central < 2 2 - 2.5 > 3.75
Central East < 2.15 2.15 - 2.75 > 2.75
South East < 1.6 1.6 - 2 > 2
*** Champlain n/a n/a n/a
North Simcoe Muskoka < 1.75% 1.75 - 2.25 > 2.25
North East < 1.8 1.8 - 2.25 > 2.25
North West < 1.7 1.7 - 2 > 2
Provincial Aggregate < 2 2 - 2.5 > 2.5
* LHIN has poor hospital coverage (limited data)
** Trends somewhat variable
*** No appropriate peaking observed, LHIN has moderate hospital coverage (somewhat limited data)
Values are based on only asthma seasons, cut-off values may be modified as more data becomes available.

Note: Cut-offs were established using 3 years of retrospective data (July 2012 to July 2015).  Counts were normalized and averaged over the 3 year period.  Data included only complaints in ACES from ages 2-50 for the asthma syndrome.  Raw counts and graphical trends can be made available upon request.

Additional Information

  • The colour coding rating for the overall province is based on the overall trends in province-wide asthma related trends in acute care emergency room visits.
  • The colour coding system shown on the map of Ontario is customized to individual LHIN geographies by the ACES team after historical review of baseline data.
  • This map uses the percentage of outpatient visits to hospital emergency departments for asthma related complaints to measure the asthma activity level within a LHIN.  This data is collected in real time from participating hospitals and reviewed weekly by the ACES team.
  • Maps are updated every Monday, so there is a maximum time lag of one week depending on when the website is accessed.  
  • Asthma Mapper does not display levels of asthma activity specific to a particular population (i.e., school children) or region (i.e., a given city).  Clusters of increased asthma activity occurring in a single city or certain population may or may not cause the entire LHIN to display high activity levels.  Persons with asthma should be aware that their individual risk may therefore be different than what is shown on the map.
  • Data displayed in this map is based on data collected from local hospitals in ACES.  The data is preliminary and may change as more data is received.  Differences in the data presented here by ACES and independently by some local health agencies likely represent differing levels of data completeness.  Data presented by local health agencies likely being the more complete.
  • The Air Quality Health Index (AQHI) layers included for the map as an indicator of outdoor air quality intended to help Canadians protect their health on a daily basis from the negative effects of air pollution.  The AQHI has been developed and is monitored by Health Canada and Environment Canada.
  • ACES has been validated as a tool for asthma surveillance by exploring correlation with retrospective NACRS (National Ambulatory Care Reporting System) data.  ACES and NACRS (J-45, asthma) 7-day average emergency department visits are correlated with an r coefficient of 0.91.
  • ACES validation and real-time data used in Asthma Mapper draw asthma complaints for individuals aged 2 to 50.
  • Colour coding is not available across all LHINs due to insufficient data.  Additionally, when geo-coding individual complaints into specific LHINs, an error rate of <5% was obtained.

The analysis is done on the data provided in real-time to the ACES system from hospital partners.  The data is analyzed weekly, on Mondays, for the data available up to the week ending Saturday.  The website will be updated no later than the end of the business day that same Monday.

Asthma Resources

The epidemic curves for the provincial summary of data are here.

Epicurve Graph