Data quality, concepts and methodology: Footnotes

View the most recent version.

Archived Content

Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please "contact us" to request a format other than those available.

Archived

This page has been archived on the Web.

Related to all tables:

Five-year survival ratios, by age and sex, Canada (excluding Quebec)

1. The Canadian Cancer Registry (CCR) is a dynamic database that can be updated with new records or changes to previous records, therefore, survival data may vary from one release to the next.
2. World Health Organization, International Classification of Diseases for Oncology, Third Edition (ICD-O-3) and Surveillance, Epidemiology, and End Results (SEER) Program primary site groups, with mesothelioma and Kaposi's sarcoma as separate groups.
3. Population-based survival estimates are based on the experience of a group of people with a heterogeneous mix of disease characteristics and as such are useful "average" outcome indicators. However, they do not necessarily reflect a specific person's chances of surviving for a given time (for example five years) after diagnosis nor do the accompanying confidence intervals represent the range of possible prognoses for individual patients.
4. Observed survival is defined as the proportion of patients alive after a given length of follow-up.
5. Relative survival is defined as the ratio of the observed survival for a group of individuals diagnosed with cancer to the survival that would have been expected for members of the general population who have the same main factors affecting survival (sex, age, place of residence) as those with cancer.
6. Expected survival proportions were derived, from sex-specific complete provincial life tables produced by Statistics Canada, using the Ederer II approach. Source: Ederer F, Heise H. The effect of eliminating deaths from cancer on general population survival rates, methodological note 11, End Results Evaluation section, National Cancer Institute; August 1959.
7. The following cases are excluded: subjects with an unknown year of birth or death; subjects under 15 or over 99 years of age at diagnosis; subjects diagnosed through autopsy only or death certificate only.
8. The 95% confidence interval (CI) illustrates the degree of variability associated with an estimate. Wide confidence intervals indicate high variability, thus, these estimates should be interpreted with due caution. When estimates are based on a small number of cases, it is more likely that observed differences are due to random, rather than systematic influences.
9. Non-standardized survival estimates provide information on the actual survival experience of the patient group. However, because survival estimates vary with age and the age distribution of cancer cases can vary over time and between geographic areas, it is usually preferable to use age-standardized estimates to compare survival across time, across provinces, or between provinces and Canada.
10. Some provincial and territorial cancer registries differ with respect to methods of data collection and registration of multiple primary cancers (more than one diagnosis of a primary cancer). There are also variations in the percentage of death certificate only (DCO) cases and the aggressiveness of follow-up, which varies by province or territory.
11. Age-specific and 'all ages' (15 to 99 years) estimates based on fewer than 10 cases were suppressed.
12. Data from Quebec have been excluded because of issues in correctly ascertaining the vital status of cases.

Age-standardized five-year survival ratios, by sex, Canada and selected provinces

1. The Canadian Cancer Registry (CCR) is a dynamic database that can be updated with new records or changes to previous records, therefore, survival data may vary from one release to the next.
2. World Health Organization, International Classification of Diseases for Oncology, Third Edition (ICD-O-3) and Surveillance, Epidemiology, and End Results (SEER) Program primary site groups, with mesothelioma and Kaposi's sarcoma as separate groups.
3. Population-based survival estimates are based on the experience of a group of people with a heterogeneous mix of disease characteristics and as such are useful "average" outcome indicators. However, they do not necessarily reflect a specific person's chances of surviving for a given time (for example five years) after diagnosis nor do the accompanying confidence intervals represent the range of possible prognoses for individual patients.
4. Observed survival is defined as the proportion of patients alive after a given length of follow-up.
5. Relative survival is defined as the ratio of the observed survival for a group of individuals diagnosed with cancer to the survival that would have been expected for members of the general population who have the same main factors affecting survival (sex, age, place of residence) as those with cancer.
6. Expected survival proportions were derived, from sex-specific complete provincial life tables produced by Statistics Canada, using the Ederer II approach. Source: Ederer F, Heise H. The effect of eliminating deaths from cancer on general population survival rates, methodological note 11, End Results Evaluation section, National Cancer Institute; August 1959.
7. The following cases are excluded: subjects with an unknown year of birth or death; subjects under 15 or over 99 years of age at diagnosis; subjects diagnosed through autopsy only or death certificate only.
8. The 95% confidence interval (CI) illustrates the degree of variability associated with an estimate. Wide confidence intervals indicate high variability, thus, these estimates should be interpreted with due caution. When estimates are based on a small number of cases, it is more likely that observed differences are due to random, rather than systematic influences.
9. Age-standardized survival estimates are interpretable as the overall survival estimate that would have occurred, if the age distribution of the patient group under study had been the same as that of the standard population. Unless they have been age-standardized to the same population, survival estimates from other sources should not be compared with those presented here.
10. Estimates were age-standardized using the direct method. Age-specific estimates for a given cancer were weighted to the age distribution of persons diagnosed with that cancer from 2001 to 2005 (based on the July 2010 tabulation master file).
11. Some provincial and territorial cancer registries differ with respect to methods of data collection and registration of multiple primary cancers (more than one diagnosis of a primary cancer). There are also variations in the percentage of death certificate only (DCO) cases and the aggressiveness of follow-up, which varies by province or territory.
12. Age-standardized estimates were suppressed if two or more of the age-specific estimates used in their calculation were based on fewer than five cases or one of the age-specific estimates was based on fewer than five cases and the total number of cases for all age groups combined was less than 100.
13. Data from Quebec have been excluded because of issues in correctly ascertaining the vital status of cases.
14. Results for the territories are not shown because of an insufficient number of cases for analysis. Cases from these areas are, however, included in the national estimates.

Five-year survival ratios, by sex, selected provinces

1. The Canadian Cancer Registry (CCR) is a dynamic database that can be updated with new records or changes to previous records, therefore, survival data may vary from one release to the next.
2. World Health Organization, International Classification of Diseases for Oncology, Third Edition (ICD-O-3) and Surveillance, Epidemiology, and End Results (SEER) Program primary site groups, with mesothelioma and Kaposi's sarcoma as separate groups.
3. Population-based survival estimates are based on the experience of a group of people with a heterogeneous mix of disease characteristics and as such are useful "average" outcome indicators. However, they do not necessarily reflect a specific person's chances of surviving for a given time (for example five years) after diagnosis nor do the accompanying confidence intervals represent the range of possible prognoses for individual patients.
4. Observed survival is defined as the proportion of patients alive after a given length of follow-up.
5. Relative survival is defined as the ratio of the observed survival for a group of individuals diagnosed with cancer to the survival that would have been expected for members of the general population who have the same main factors affecting survival (sex, age, place of residence) as those with cancer.
6. Expected survival proportions were derived, from sex-specific complete provincial life tables produced by Statistics Canada, using the Ederer II approach. Source: Ederer F, Heise H. The effect of eliminating deaths from cancer on general population survival rates, methodological note 11, End Results Evaluation section, National Cancer Institute; August 1959.
7. The following cases are excluded: subjects with an unknown year of birth or death; subjects under 15 or over 99 years of age at diagnosis; subjects diagnosed through autopsy only or death certificate only.
8. The 95% confidence interval (CI) illustrates the degree of variability associated with an estimate. Wide confidence intervals indicate high variability, thus, these estimates should be interpreted with due caution. When estimates are based on a small number of cases, it is more likely that observed differences are due to random, rather than systematic influences.
9. Non-standardized survival estimates provide information on the actual survival experience of the patient group. However, because survival estimates vary with age and the age distribution of cancer cases can vary over time and between geographic areas, it is usually preferable to use age-standardized estimates to compare survival across time, across provinces, or between provinces and Canada.
10. Some provincial and territorial cancer registries differ with respect to methods of data collection and registration of multiple primary cancers (more than one diagnosis of a primary cancer). There are also variations in the percentage of death certificate only (DCO) cases and the aggressiveness of follow-up, which varies by province or territory.
11. Age-specific and 'all ages' (15 to 99 years) estimates based on fewer than 10 cases were suppressed.
12. Data from Quebec have been excluded because of issues in correctly ascertaining the vital status of cases.
13. Results for the territories are not shown because of an insufficient number of cases for analysis.

Previous