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4A Chronic disease hospitalization

Description | Specific Indicators | Ontario Public Health Standards (OPHS)Corresponding National Indicator(s) from Statistics Canada and CIHI | Data Sources |  Alternative Data Sources | ICD Codes | Analysis Check List | Method of Calculation |  Basic Categories | Indicator Comments | Definitions |Cross-References to Other Indicators | Cited References | Other References | Changes Made 


  • The total hospitalization rate for a selected chronic disease is the total number of inpatient discharges for the selected disease per total population (usually expressed per 100,000) over a specified period of time.
  • Age-specific hospitalization rate is the number of inpatient discharges for the selected disease per 100,000 population in that age group over a specified period of time.
  • Age-standardized hospitalization rate (SRATE) for a selected chronic disease is the number of inpatient discharges from the selected disease that would occur if the population had the same age distribution as the 1991 Canadian population (per 100,000) over a specified period of time.
  • Standardized morbidity ratio (SMR) for a selected chronic disease is the ratio of observed inpatient discharge by specific disease to the number expected if the population had the same age-specific hospitalization rates as Ontario over a specified period of time.
Specific Indicators
  • Total hospitalization rate/ Age-specific hospitalization rates/ SRATE /SMR for:

o Cardiovascular disease
o Ischemic heart disease
o Cerebrovascular disease
o Stroke
o Hypertensive disease
o Respiratory disease
o Chronic obstructive pulmonary disease (COPD)
o Lower respiratory tract diseases
o Asthma
o Diabetes

Ontario Public Health Standards (OPHS)

The Ontario Public Health Standards (OPHS) establish requirements for the fundamental public health programs and services carried out by boards of health, which include assessment and surveillance, health promotion and policy development, disease and injury prevention, and health protection. The OPHS consist of one Foundational Standard and 13 Program Standards that articulate broad societal goals that result from the activities undertaken by boards of health and many others, including community partners, non-governmental organizations, and governmental bodies. These results have been expressed in terms of two levels of outcomes: societal outcomes and board of health outcomes. Societal outcomes entail changes in health status, organizations, systems, norms, policies, environments, and practices and result from the work of many sectors of society, including boards of health, for the improvement of the overall health of the population. Board of health outcomes are the results of endeavours by boards of health and often focus on changes in awareness, knowledge, attitudes, skills, practices, environments, and policies. Boards of health are accountable for these outcomes. The standards also outline the requirements that boards of health must implement to achieve the stated results.

Link to OPHS

Protocol Requirements Related to this Indicator

  • The board of health shall collect or access the following types of population health data and information: Morbidity, including...prevalence of chronic diseases (Population Health Assessment and Surveillance Protocol, 1b)

Goal Related to this Indicator

  • To reduce the burden of preventable chronic diseases of public health importance (Chronic disease prevention).*

* Chronic diseases of public health importance include cardiovascular diseases, cancer, respiratory diseases, and type 2 diabetes

Corresponding National Indicators

  • None

Data Sources

Numerator: Hospitalization
Original source: Canadian Institute for Health Information (CIHI) Discharge Abstract Database (DAD)
Distributed by: Ontario Ministry of Health and Long-Term Care: IntelliHEALTH ONTARIO
Suggested citation (see Data Citation Notes): Inpatient Discharges [years], Ontario Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: [date].

Denominator: Population Estimates
Original source: Statistics Canada
Distributed by: Ontario Ministry of Health and Long-Term Care: IntelliHEALTH ONTARIO
Suggested citation (see Data Citation Notes): Population Estimates [years]*, Ontario Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, Date Extracted: [date].
* Note: Use the total years of the estimates, including the most recent year, even if not all were used in the analysis. The years used in the analysis should be included in the report itself.
ICD Codes

  • Cardiovascular disease: Diseases of the circulatory system (ICD-9: 390-459); (ICD-10-CA: I00-I99) 
  • Ischemic heart disease (ICD-9: 410-414); Ischemic heart diseases (ICD-10-CA: I20-I25)
  • Cerebrovascular disease (ICD-9: 430-434,436-438); (ICD-10-CA: I60-I69)
  • Stroke (ICD-9: 430, 431, 434, 436); (ICD-10 I60, I61, I63, I64)
  • Hypertensive disease (ICD-9: 401-405); (ICD-10: I10-I15)
  • Respiratory disease: Diseases of the respiratory system (ICD-9:460-519); (ICD-10-CA: J00-J99)
  • Chronic Obstructive Pulmonary Disease (ICD-9: 490-492, 496); (ICD-10-CA: J40-J44)
  • Chronic lower respiratory tract disease
    • ICD-9 490, 496
      • Bronchitis (490, 491)/empysema (492)/asthma (493)/bronchiectasis (494)/chronic airways obstruction, not elsewhere classified (496)
      • (excluded 495, extrinsic allergic alveolitis)
    • ICD-10-CA J40-J47
      • Bronchitis, chronic and unspecified (J40-J42)/emphysema (J43)/other chronic obstructive pulmonary disease (J44)/asthma (J45)/bronchiectasis (J47)
  • Asthma (ICD: 493); (ICD-10-CA: J45)
  • Diabetes (ICD-9: 250); (ICD-10-CA: E10-E14)

    Note: J46 (status asthmaticus) has been excluded from the ICD-10-CA manual.  Status asthmaticus is included in ICD-10_CA as a detailed code under J45 (i.e. J45.91, Asthma, unspecified, with stated status asthamatics).  Hospitalization data uses ICD-10-CA codes and therefore excludes J46. However, J46 is included in mortality data, as mortality data uses ICD-10 codes.

Analysis Check List
  • Consider aggregation of data values and/or cell suppression when dealing with small numbers to avoid risk of confidentiality breach. A new resource is currently under development to provide more detailed information on this issue.
  • For in-patient discharges in intelliHEALTH: use Inpatient Discharge Main Table data source from the ‘05 Inpatient Discharges' folder and # Dschg as Measure
  • For in-patient separations in PHPDB (through Intellihealth):
    • Use Inpatient Discharge Main Table data source from the ‘05 Inpatient Discharges' folder.
    • Filter for Admit Entry Type not equal to ‘N' and ‘S' - to exclude healthy newborns and stillbirths from your counts, as ICES and CIHI do for their publications.
    • Filter for Hospital Type = AT (Acute Treatment) or AP (Acute Psychiatric) - to include only acute care hospitals.
    • Select # Dschgs measure.
  • In your report, select the appropriate geography of patient (public health unit, LHIN) and use the pre-defined filter to select your area before you run your report. Hospital information (hospital name, PHU or LHIN) can also be selected in your report.
  • ICD-10-CA has a greater level of specificity and different code titles than ICD-9. CIHI does not endorse forward conversions because of differences in the classification systems. Refer to Resources: ICD-10-CA for more information.
  • Note: inpatient data are reported by fiscal year (April 1 - March 31). Any changes in the source data occur on a fiscal year basis (e.g., ICD10 reporting began on April 1, 2002) and will affect reporting by calendar year.

Method of Calculation

Total Hospitalization Rate:

total number of inpatient discharges by ICD code

    x 100,000

total population


Age Specific Hospitalization Rate:

annual number of inpatient discharges by ICD code in an age group

    x 100,000

total population in that age group


SRATE (See Resources: Standardization of Rates):

Sum of (age-specific hospitalization rate x 1991 Canadian population in that age group)

    x 100,000

Sum of 1991 Canadian population 


SIR (See Resources: Standardization of Rates):

Sum of hospitalizations by ICD code in the population


Sum of (Ontario age-specific rate x population in that age group)

Basic Categories

  • Age groups for age-specific rates: <1, 1-19, 20-44, 45-64, 65-74, 75+, total. (Age Group (CD) in IntelliHEALTH)
  • Sex: male, female.
  • Geographic areas: public health unit, census division, census sub-division, LHIN.

Indicator Comments

  • Cardiovascular disease is a term that refers to more than one disease of the circulatory system including the heart and blood vessels, whether the blood vessels are affecting the lungs, the brain, kidneys or other parts of the body. The Public Health Agency of Canada identifies six types of cardiovascular disease: ischemic heart disease, cerebrovascular disease (stroke), peripheral vascular disease, heart failure, rheumatic heart disease, and congenital heart disease.1
  • Cardiovascular disease (CVD) is the leading cause of hospitalization in Canada, particularly in older age groups.2
  • Although stroke and cerebrovascular disease are often used interchangeably, stroke is more specific. Cerebrovascular disease includes more unspecified and ill-defined ICD codes as well as late effects of cerebrovascular disease. Users should choose one or the other and clearly document the codes they have used.
  • the APHEO definition of stroke excludes ICD-10-CA code I62 (i.e., "other non-traumatic intracranial maemorrhage") and is therefore different from the Canadian Institute for Health Information (CIHI) definition of stroke.  Although patients with "other traumatic intracranial haemorrhage"may present with stroke-like symptoms, the etiology is different than stroke and definitive diagnosis depends on technology which may be less available in smaller regions and hospitals.  CIHI includes I62 in their calculations, recognizing that this approach will result in some false positives, but rates based on total counts will be more comparable between regions across Canada.
  • The ICD-10-CA codes included in the APHEO 'hypertensive diseases' specific indicator correspond to those used by both CIHI and Public Health Agency of Canada (PHAC).
  • The respiratory disease category includes mostly chronic but some acute diseases as well. Influenza and pneumonia are included but lung cancer is not. Over 10% of deaths in Canada in 2004/05 were due to respiratory diseases, primarily COPD, influenza and pneumonia, and asthma.3
  • Although Chronic Obstructive Lung Disease (COLD) and Chronic Obstructive Pulmonary Disease (COPD) are often used interchangeably, COLD includes asthma, bronchiectasis, and extrinsic allergic alveolitis, whereas COPD does not. COPD consists only of bronchitis, emphysema, and chronic airways obstruction not elsewhere classified. Since some data systems use the COLD grouping of 490-496 but refer to it as COPD, users should check documentation closely. COPD is used by Health Canada and is recommended in this indicator. The chapter on respiratory disease in Public Health and Preventive Medicine, 11th Edition, John Last (Ed.) notes that the term COLD was introduced in the 1960s.4 It states "comparisons between different countries using different diagnostic criteria may be more valid when the separate categories are combined. But for most purposes, every effort should be made to use precise, clearly defined diagnostic criteria".
  • 'Chronic lower respiratory disease' specific indicator, which includes 'other chronic obstructive pulmonary diseases' (J44) and bronchiectasis (J47) has replaced the 'bronchitis/emphysems/asthma' specific indicator.  Bronchiectasis is characterized by permanent dilatation of the bronchi and bronchioles and secretion retention, and often accompanied by shortness of breath, recurrent lung infection, and reduced general health status.5  Bronchiectasis may be a comorbid condition in a substantial proportion of those with COPD and may become a more signifcant problem as COPD prevalence rises.6,7 Prevalence of bronchiectatasis has been found to be higher in indigenous communities globally, 8,9,10 possibly related to higher prevalence of lower respiratory tract infections related to living conditions in these communities.11 
  • Hospitalization data include multiple admissions for a single individual. Multiple admissions likely occur more frequently for chronic diseases.
  • Hospitalization data are influenced by the availability of services and the practice patterns of providers.
  • Hospitalization data provide only a crude measure of the prevalence of a disease or injury.
  • It is not possible to distinguish between type 1 and type 2 diabetes from administrative data. Previously, researchers made the distinction using age 30 as a cut point, but the increasing prevalence of early onset type 2 DM makes this assignment less reliable. Although separating the types of diabetes was thought to be important in the past, recent evidence regarding the benefits of aggressive management of type 2 DM may mean that the distinction is less critical from a planning and policy perspective.12
  • To best understand mortality or disease trends in a population, it is important to determine crude rates, age-specific rates and age-standardized rates (SRATES) and/or ratios (SMRs, SIRs). Although the crude death (or disease) rate depicts the "true" picture of death/disease in a community, it is greatly influenced by the age structure of the population: an older population would likely have a higher crude death rate. Age-specific rates can best describe the "true" death/disease pattern within particular age groups of a community, and allow for comparison of age groups across populations that have different age structures.
  • Since many age-specific rates are cumbersome to present, age standardized rates have the advantage of providing a single summary number that allows different populations to be compared; however, they present an "artificial" picture of the death /disease pattern in a community. For more information about standardization, refer to the Resources section: Standardization of Rates.


  • Separation – a separation from a health care facility occurs anytime a patient (or resident) leaves because of death, discharge or transfer. The number of separations is the most commonly used measure of the utilization of hospital services. Separations, rather than admissions, are used because hospital abstracts for inpatient care are based on information gathered at the time of discharge. The words 'separation', 'discharge', and 'stay' are used interchangeably.
  • Cardiovascular Diseases - All diseases of the circulatory system including congenital and acquired diseases such as acute myocardial infarction (heart attack), ischemic heart disease, valvular heart disease, peripheral vascular disease, arrhythmias, high blood pressure, and stroke.13
  • Chronic Obstructive Pulmonary Disease (COPD) - A chronic disease with shortness of breath, cough and sputum production, also referred to as chronic bronchitis and emphysema.3

Cross-References to Other Indicators

Cited References

  1. Public Health Agency of Canada. Six types of Cardiovascular Disease. Available online at: (Accessed on June 18, 2009).
  2. RE Hall, JV Tu. Hospitalization rates and length of stay for cardiovascular conditions in Canada, 1994 to 1999. Can J Cardiol 2003;19(10):1123-1131. Available in the CCORT Canadian Cardiovascular Atlas listed below.
  3. Public Health Agency of Canada. Life and Breath: Respiratory Disease in Canada. Ottawa, ON: Public Health Agency of Canada, 2007. Available at:
  4. Higgins I. Respiratory Disease. In: Last J (Ed.), Maxcy-Rosenau Public Health and Preventive Medicine. Eleventh Edition. New York: Appleton-Century-Crofts, New York, 1980.
  5. Neves PC, Guerra M, Ponce P, Mirand J, Vouga L. Non-cystic fibrosis bronchiectasis. Interactive cardiovascular and Thoracic surgery.2011 [cited 2013 Jun 28];13:619-25. Available from:
  6. Patel IS, Vlahos I, Wilkinson MA, Lloyd-Owen SJ, Donaldson GC, Wilks M, et al. Bronchiectasis, exacerbation indices, and inflammation in chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2004;170:400-7. Available from:
  7. Rademacher J, Welte T. Bronchiectasis - diagnosis and treatment. Dtsch Arztebl Int 2011; 108(48): 809-15.
  8. Subie HA, Fitzgerald DA. Non-cystic fibrosis bronchiectasis. J Paed Child Health. 2012;48:382-8.  
  9. Chang AB, Grimwood K, Mulholland EK, Torzillo PJ. Bronchiectasis in indigenous children in remote Australian communities. Med J Aust. 2002 [cited 2013 Jun 28];177:200-4. Available from:
  10. Singleton R, Morris A, Redding G, Poll J, Holck P, Martinez P, et al. Bronchiectasis in Alaska native children: causes and clinical courses. Pediatr Pulmonol. 2000;29:182-7. 
  11. Peck AJ, Holman RC, Curns AT, Lingappa JR, Cheeck JE, Singleton RJ, et al. Lower respiratory tract infections among American Indian and Alaska Native children and the general population of U.S. children. Pediatr Infect Dis J. 2005;24:342-51.
  12. Hux J, Booth G, Slaughter P, Laupacis A (Eds.) Diabetes in Ontario: An ICES Practice Atlas. Toronto, ON: Institute for Clinical Evaluative Sciences, 2003. Available at:
  13. Public Health Agency of Canada. Tracking Heart Disease and Stroke in Canada. Ottawa, ON: Public Health Agency of Canada, 2009. Available at:

Other References 

Changes Made


Type of Review - Formal Review or Ad-Hoc? 

Changes made by 


June 18, 2009Formal Core Indicators Working Group
  • Changed hospital separation to inpatient discharge.
  • Changed specific indicator name from circulatory disease to cardiovascular disease.
  • Changed name of "stroke (cerebrovascular disease)" indicator to cerebrovascular disease and changed ICD-9 codes to exclude transient cerebral ischemia (435) since ICD-10 codes already excluded this. In addition "stroke" was added as a specific indicator along with some related indicator comments explaining the difference.
  • Added respiratory disease as a specific indicator and some related indicator comments.
  • Added asthma codes which were previously missing.
  • Removed specific indicator for Chronic Obstructive Lung Disease (ICD-9: 490-494, 496); (ICD-10-CA: J40-47) as this was only relevant to the 1997 Mandatory Health Programs and Services Guidelines.
  • Added comments regarding type 1 vs type 2 diabetes and problems with deaths being coded as diabetes.
  • Information for this indicator was updated based on the most recent version of the Guide to Creating or Editing Core Indicators Pages and the most recent available data.
  • References were revised with up-to-date literature.
July 2, 2013Ad hocNatalie Greenidge on behalf of the CIWG
  • Added indicator comments related to standardization of rates
July 11, 2013Ad hoc HEAL Subgroup
  • ‘Bronchitis/asthma/emphysema' specific indicator (ICD-10-CA: J40-J42, J43, J45-J46) was replaced with "Chronic lower respiratory tract diseases" (J40-45, J47)
  • Indicator comments were added to support including bronchiectasis (i.e., J47) in the ‘lower respiratory tract diseases' specific indicator; to highlight the difference in APHEO and CIHI definitions of ‘stroke' (i.e., APHEO Core Indicator excludes ICD-10-CA code I62); and to indicate that APHEO definition of ‘hypertensive disease' is the same as that used by both CIHI and PHAC


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