Describes those individuals with asthma who had at least one Ontario Health Insurance Program (OHIP) claim, emergency department (‎ED) visit or hospitalization for ‎ asthma in a fiscal year‎. ‎These individuals are a subset of the asthma prevalence cohort.‎

Asthma-related conditions include acute respiratory infections, other diseases of the upper respiratory tract, pneumonia and influenza, COPD and allied conditions, other diseases of lung or respiratory system, atopic dermatitis and related conditions, and symptoms involving respiratory system and other chest symptoms. In adults, asthma-related conditions also include gastro-esophageal reflux disorder, heartburn and allergic contact dermatitis. Please contact us for detailed ICD codes used in evaluating asthma-related conditions.

A five-level instrument used to guide the triage process in Canadian emergency departments.

  • Level 1 (resuscitative): Conditions that are threats to life or limb (or imminent risk of deterioration) requiring aggressive interventions. Time to MD: immediate. Time to nurse: immediate.
  • Level 2 (emergent): Conditions that are a potential threat of life, limb or function, requiring rapid medical intervention or delegate acts. Time to MD: 15 minutes. Time to nurse: immediate.
  • Level 3 (urgent): Conditions that could potentially progress to a serious problem requiring emergency intervention. May be associated with significant discomfort or affecting ability to function at work or activities of daily living. Time to MD:
  • Level 4 (less urgent): Conditions related to patient age, distress, or potential for deterioration or complications that would benefit from intervention or reassurance within one to two hours. Time to MD:
  • Level 5 (non-urgent): Conditions that may be acute but non-urgent as well as conditions which may be part of a chronic problem with or without evidence of deterioration. The investigation or interventions for some of these illnesses or injuries could be delayed or even referred to other area of hospital or heath care system. Time to MD: 120 minutes. Time to nurse: 120 minutes.1

1CTAS: Canadian Triage and Acuity Scale Implementation Guidelines, CJEM Oct 1999 Special Supplement.

The Ontario Marginalization Index (ON-Marg) is a census and geographically based index derived to show differences in marginalization between areas and to understand inequalities in various measures of health and social well-being in populations or geographical areas. This index includes four dimensions, including material deprivation (no high school graduation, lone parent families, government transfers, unemployment, low income, homes needing major repairs), dependency (seniors, ratio of population ages 0 to 14 and 65+ to population ages 15 to 64, labour force participation), residential instability (living alone, youth, persons per dwelling, apartments, married, owner-occupied house, residential mobility in past five years) and ethnic concentration (recent immigrants and visible minorities). The index applies to small, relatively stable population between 2,500 and 8,000 living with similar economic and social conditions. In these analyses we used the deprivation domain as a proxy measure of socio-economic status, expressed in quintiles, with Q1 being the least and Q5 the most deprived populations.2

2Matheson FI, Moineddin R, Dunn JR, Creatore MI, Gozdyra P, Glazier RH: Urban neighborhoods, chronic stress, gender and depression. Soc Sci Med 2006, 63(10):2604-2616.

Our asthma statistics separate ED wait time into three categories:

  • Triage 1 (time from triage to physician assessment): This measures the time a patient waits in the ED before initial assessment by a physician occurs. This interval of time starts once the patient has registered in the ED (or has been triaged, whichever came first) and stops once they are initially assessed by a physician.
  • Triage 2 (time from physician assessment to disposition): This measures the time (in minutes) between the patient’s initial assessment by a physician and their eventual disposition, which could be hospital admission, admission to the intensive care unit, death, or discharge. This interval of time starts once the patient has been initially assessed by a physician, and stops when a decision is reached regarding their eventual disposition.
  • Total (time from triage to disposition): This measures the time that a patient waits in the ED before their eventual disposition. This interval of time starts once the patient has registered in the ED (or has been triaged, whichever came first) and stops once a decision is reached regarding their eventual disposition.

These statistics also refer to four hospital types:

  • Paediatric hospitals are those for patients ≤18 years of age.
  • Small hospitals are single community providers with <2,700 inpatient acute, CCC and day surgery weighted cases.
  • Teaching hospitals have membership in the Council of Academic Hospitals of Ontario (CAHO).
  • Community hospitals encompass those hospitals not defined as small or teaching.

Incidence is the number of new cases of a given condition over a specific time period, divided by the number of people at risk over that same time period.

Socioeconomic status was inferred from neighbourhood income derived from postal codes and census data and is expressed in quintiles.3

3Wilkins R. PCCF+ Version 4D User’s Guide (Geocodes/PCCF). Automated Geographic Coding Based on the Statistics Canada Postal Code Conversion Files, Including Postal Codes to December 2003. Ottawa: Statistics Canada, 2004.

The prevalence is the number of people with the condition. The formula for the prevalence rate is:

  • Prevalence Rate = (Number of people with the condition) / Population

Rural communities are defined as those with fewer than 10,000 people.