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3 All-Cause Hospitalization

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


  • The crude hospitalization rate is the total number of hospital separations (discharges, transfers and deaths) during a given year (fiscal or calendar) per total population (per 100,000).
  • Age-specific hospitalization rate for a selected cause is the number of hospitalizations in a given age group from a selected cause per 100,000 population in that age group over a specified period of time.
  • Age-standardized hospitalization rate (SRATE): the number of hospital separations for a given population that would occur if the population had the same age distribution as the 1991 Canadian population (per 100,000).
  • Standardized morbidity ratio (SMR): the ratio of observed hospital separations to the number expected if the population had the same age-specific hospitalization rates as Ontario.

Note: This indicator excludes external causes of hospitalization and mental disorders. See ICD Codes section for more details.

Specific Indicators

  • Crude Hospitalization Rate
  • Age-Specific Hospitalization Rate
  • Age-Standardized Hospitalization Rate (SRATE)
  • Standardized Morbidity Ratio (SMR)

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 endeavors 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.

Protocol Requirements Related to this Indicator

The board of health shall collect or access the following types of population health data and information:

  • iii) Morbidity, including incidence of reportable diseases, surveillance of other infectious diseases of public health importance, incidence of injury as assessed by in-patient hospitalizations and emergency department visits, and 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 Indicators from Statistics Canada and CIHI

  • None

Data Sources 

Numerator: Hospitalization
Original source: Discharge Abstract Database (DAD), Canadian Institute for Health Information (CIHI)
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].

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: For population estimates, cite 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   


Chapter Title

ICD Codes


Infectious and Parasitic Diseases 






Endocrine, Nutritional, and Metabolic Diseases and Immunity Disorders



Diseases of Blood and Blood Forming Organs



Mental Disorders



Diseases of the Nervous System and Sense Organs



Diseases of the Circulatory System Cardiovascular Disease



Diseases of the Respiratory System 



Diseases of the Digestive System



Disease of the Genitourinary System



Complications of Pregnancy, Childbirth, and the Puerperium



Diseases of the Skin and Subcutaneous Tissue



Diseases of the Musculoskeletal System and Connective Tissue 



Congenital Anomalies 



Certain Conditions Originating in the Perinatal Period 



Symptoms, Signs, and Ill-Defined Conditions



Injury and Poisoning



External Causes of Injury and Poisoning 



Certain infectious and parasitic diseases 






Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism



Endocrine, nutritional and metabolic diseases



Mental and behavioural disorders



Diseases of the nervous system



Diseases of the eye and adnexa 



Diseases of the ear and mastoid process 



Diseases of the circulatory system 


Diseases of the respiratory system 



Diseases of the digestive system



Diseases of the skin and subcutaneous tissue



Diseases of the musculoskeletal system and connective tissue



Diseases of the genitourinary system 



Pregnancy, childbirth and the puerperium 



Certain conditions originating in the perinatal period



Congenital malformations, deformations, and chromosomal abnormalities 



Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified



Injury, poisoning and certain other consequences of external causes



External causes of morbidity and mortality 



Factors influencing health status & contacts with health services



Provisional codes for research & temporary assignment

U Codes

1 Mental Disorders (ICD9, ICD10 Chapter V) are excluded from this indicator because of changes in reporting mental disorders that started on April 1, 2006 (2006 fiscal year). As of that date, patients with mental disorders who occupy designated psychiatric beds in acute care hospitals have been reported through the Ontario Mental Health Reporting System (OHMRS) rather than through the DAD. These patients represent > 90% of inpatient stays for mental disorders. Furthermore the DSM-IV diagnosis codes, rather than ICD10 codes are used in OHMRS, and the reporting is based on admission rather than discharge. So combining these sources for reporting is not possible. The exclusion of discharges with a mental disorder diagnosis should be clearly noted in a highly visible area of any report.

2External Causes of morbidity and mortality (ICD9 Chapter XIX, ICD10 Chapter XX) - are never reported as the most responsible diagnosis for an inpatient discharge; instead the resulting injury or condition (e.g. head injury) or other disease is reported as the most responsible diagnosis. Because of this, external causes are excluded from the all-cause hospitalization indicator (see injury section for more information on reporting these data).

3 Chapters XXI and Chapter XXIII are excluded as they do not represent diseases or conditions.

International Shortlist for Hospital Morbidity Tabulation (130 groups)1 

The International Shortlist for Hospital Morbidity Tabulation (ISHMT) is a set of groupings developed by the Hospital Data Project (HDP) of the European Union Health Monitoring Programme for statistical comparison of hospital activity analysis.  It was adopted in 2005 by Eurostat, the OECD (Organisation for Economic Co-operation and Development) and the WHO-FIC (Family of International Classifications) Network. It provides groupings below the level of ICD10 Chapter, e.g. diabetes is in a separate group from other endocrine, nutritional and metabolic diseases.

ICD10 Block Codes (236 groups)2

The ICD10 Blocks are a set of ICD10 groupings provided by the Canadian Institute for Health Information (CIHI). They provide categories below the level of the ISHMT.  For example the blocks separate influenza & pneumonia from other lower respiratory diseases.

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 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.
    • Filter for ICD10 Chapter not equal to 5 (V Mental and Behavioural Disorders) and ICD9 Chapter not equal to 5 (V Mental Disorders) - to exclude stays with a mental disorder as the most responsible diagnosis.
    • 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.
  • Note: inpatient data are reported by fiscal year (April 1 - March31). 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 

Crude Hospitalization Rate:
total number of hospitalizations

total population
 X 100,000

Age-specific Hospitalization Rate:
total number of hospitalizations in an age group

total population in that age group
 X 100,000

SRATE (See Resources: Standardization of Rates):
Sum of (age-specific hospitalization rate X 1991 Canadian population in that age group)
Sum of 1991 Canadian population
 X 100,000

SMR (See Resources: Standardization of Rates):
Sum of hospitalizations in the population for that age group
Sum of (Ontario age-specific rate X population in that age group)

Basic Categories

  • Age groups - suggested age groupings are the chronic disease age groups (Age Group (CD) in Intellihealth -<1-19 yr, 20-44, 45-64, 65-74, 75+) or the infant + 5-yr age groups (Age Group (inf,5yr) in Inteallihealth - <1, 1-4, then 5 yr groups to 90+).
  • Sex: male, female and total.
  • ICD Chapters for overview; International Shortlist for Hospital Morbidity Tabulation for more detailed groupings (130 groups, e.g. diabetes rather than all endocrine & metabolic disorders); ICD10 Blocks for a larger number of groups (236 groups, e.g. influenza & pneumonia separated from other acute lower respiratory). There are pre-defined filters for all three groupings (Chapter, ISHMT, ICD10 Block) in Intellihealth for reporting only select groups.
  • Geographic areas of patient residence: Local Health Integration Network (LHIN), public health unit, county, municipality, forward sortation area (1996 onward) and postal code (1996 onward).

Indicator Comments

  • 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.
  • Reflects the middle range of the disease severity continuum.
  • Causes are based on the most responsible diagnosis (diagnosis associated with the longest duration of treatment) during a given hospital stay.


  • 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. 

Cross-References to Other Indicators

Cited Reference(s)

  1. Hospital Data Project (HDP) of the European Union Health Monitoring Programme. International Shortlist for Hospital Morbidity Tabulation (ISHMT). Eurostat/OECD/WHO, version 2006. Available online at: 
  2. ICD10-CA Codes Table, Ministry of Health and Long-Term Care, IntelliHEALTH ONTARIO, March 2009 (note: available to licensed users only).

Other Reference(s)

  • Canadian Institute for Health Information. DAD Abstracting Manual (for use with ICD-10-CA/CCI) 2009-2010. Ottawa, ON: Canadian Institute for Health Information, 2009.
  • Appendix: A Summary of Studies on the Quality of Health Care Administrative Databases in Canada. In: Goel V, Williams JI, Anderson GM, Blackstien-Hirsch P, Fooks C, Naylor CD [Eds.],  Patterns of Health Care in Ontario. The ICES Practice Atlas, 2nd edition. Ottawa: Canadian Medical Association, 1996. pp. 339-45.
  • Canadian Institute for Health Information. Data Quality of the Discharge Abstract Database Following the First-Year Implementation of ICD-10-CA/CCI Final Report. Ottawa, ON: Canadian Institute for Health Information, 2004. Available at:
  • Canadian Institute for Health Information. Discharge Abstract Database Data Quality Re-abstraction Study: Combined Findings for Fiscal Years 1999/2000 and 2000/2001. Ottawa, ON: Canadian Institute for Health Information, 2002. Available at:
  • Juurlink D, Preyra C, Croxford R, Chong A, Austin P, Tu J, Laupacis A. Canadian Institute for Health Information Discharge Abstract Database: a validation study. Toronto: Institute for Clinical Evaluative Sciences; 2006. Available at:

Changes Made



Type of Review (Formal Review or Ad Hoc?)

Changes made by


June 19, 2009

Formal review

Leading Causes subgroup of Core Indicators

  • Removed day procedures - these are ambulatory visits, not hospitalizations
  • Added new ICD10 groupings below the level of ICD10 Chapter
  • Added recommendations re: reporting mental disorders and external causes
  • Indicator was updated in alignment with the new Guide for Creating and Editing Core Indicator pages
  • Reference to HELPS database was removed

July 2, 2013Ad hocNatalie Greenidge on behalf of the CIWG 
  • Updated indicator comments related to standardization of rates
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