Cardiovascular Disease Data Qualifiers

Data Sources:

The morbidity and mortality data are derived from the Hospital Morbidity databases (Canadian Institute of Health Information) and Vital Stats (Statistics Canada).
Subsequent manipulation of the data was performed by the Chronic Disease Surveillance Division, Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada.

Limitations:

There is a lag time of approximately two-three years in the data, due mainly to collection and refinement issues associated with the provinces, Statistics Canada and Canadian Institute for Health Information. Hospitalizations are coded based on diagnosis, starting with the most significant condition or when there is more than one significant condition, the diagnosis most responsible for the longest length of stay in the hospital.

Disease Groupings:

All disease groupings follow the International Classification of Diseases (ICD) coding system created by the World Health Organization (WHO). Cardiovascular (Circulatory) disease are based on ICD-9 codes 390-459 inclusive. Ischemic heart disease currently utilizes the ICD-9 codes 410-414 and because of a historical limitation of our data system the code 429.2 is also included in this group. The codes 430-438 inclusive encompass cerebrovascular disease. And finally, ICD-9 code 410 represents acute myocardial infarction which was coded as a distinct category with the release of ICD-8 in 1969.

For more recent data, ICD-10–CA codes were used to classify the cardiovascular diseases. All cardiovascular diseases were coded as I00-I99. Ischemic heart disease was coded as I20-I25. Cerebrovascular disease was coded as I60-I69. Heart failure was coded as I50. Heart attack or acute myocardial infarction was coded as I21-I22.

Standardization:

Where indicated, data and graphs have been age standardized to the 1991 Canadian population. It would therefore be inappropriate to compare this information with similar data standardized to another year as differences may be solely related to changes in the underlying population distribution.