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Chronic Disease Surveillance Division - CCDPC - PHACCanadian Council of Cancer RegistriesHealth Statistics Division - Statistics Canada
Cancer Surveillance On-Line
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How to Use Canadian Cancer Surveillance On-Line

Instructions

Within each section, you will see a number of menu choices to narrow down your selection. Whenever you see a down arrow or slider bar, more choices are available. One or possibly more choices can be selected. The options you are allowed to select vary according to the page you are on. On certain pages you can select multiple sites, age groups or provinces. Only one multiple selection is allowed per chart. Certain sections contain buttons for 95% confidence intervals and for changing the scale from linear to logarithmic. Please see the Glossary for definitions of these terms. From the Glossary page, please use your browser's [BACK] button to return to your previous selection page. Also note the check box for black and white printing. What this does is to make sure that the charts are clear when printing. When your selections are complete, click on the [View Chart] button.

When you see your chart, you have the option of downloading the data to your personal computer. If your choices were not exactly as you wanted, please hit the back button on your browser to modify your choices. Please note on certain graphs that there may be some blank bars or lines. This is because the number of cases is too small to draw any conclusions. Not all cancer sites will be shown on certain pie charts in order to improve the appearance of the chart. At all times the glossary will be available to aid in your selection.

Methods

Incidence rates were calculated using the age distribution of the 1991 Canadian population. Comparative Incidence Figures are calculated by the ratio of the provincial or Census Division (CD) cancer incidence rate to the Canadian rate. The rates are then grouped into 5 categories, two below the Canadian average, two above and one middle category for those CDs with similar rates.

The standardized incidence ratio (SIR) is the number of new cases of a cancer that were diagnosed divided by the number that were expected, based on the age and sex composition of the population. For the information presented here, the expected numbers of new cases of cancer are based on the Canadian age-specific rate. Cases with unknown age are not included in the rates and the number of cases. For cancer incidence, there were less than 50 cases with unknown age in 1993.

Confidence intervals for the SIR were calculated using the method of Ury and Wiggins (1985). Confidence intervals for the incidence rates and corresponding CIF were calculated as described by Swift (1995).

Click here for a more thorough discussion of the statistical methods.

Standardization

As indicated above data and graphs have been age-standardized to the 1991 Canadian population. It would therefore be inappropriate to compare information with similar data standardized to another standard population because differences may be solely related to changes in the underlying population distribution. Only 5-year age groups can be directly compared.

Data Sources and Version

The source of the incidence data is the Canadian Council of Cancer Registries. Subsequent manipulation of data was performed by the Chronic Disease Surveillance Division, CCDPC, Public Health Agency of Canada. Population estimates were provided by Statistics Canada. Data quality information was provided by the provincial and territorial cancer registries and the Health Statistics Division of Statistics Canada.

Cancer incidence data for the Canada/provincial/territorial charts and maps is based on the July 2008 Canadian Cancer Registry (CCR) data release by Statistics Canada using International Agency for Research on Cancer rules for multiple primaries.

Mortality data for the Northwest Territories and Nunavut separately are not available before 1991.

Annual mortality data were provided to the Public Health Agency of Canada by Statistics Canada. The cooperation of the registrars of vital statistics in the provinces and territories of Canada who make mortality data available to Statistics Canada under federal-provincial agreements is gratefully acknowledged.

Limitations

There is a lag time of approximately two to three years in the data due mainly to collection and refinement issues associated with the provinces and territories, Statistics Canada and the Public Health Agency of Canada.

Provincial totals obtained from summing the CD values can differ slightly from the values obtained directly from the provincial files. The provincial level files contain numbers taken directly from the Canadian Cancer Registry (CCR) and are the proper totals. At the CD level, files sometimes had to be obtained directly from the Registries because of a high percentage of missing residence codes on CCR. The overall percentage of missing residence codes in all provinces is less than 4%.

Information on cancer in the young will differ somewhat from Health Canada's publication and internet document entitled This Battle Which I Must Fight: Cancer in Canada's Children and Teenagers. This document contains the most accurate data up to 1991 since individual cases were specifically reviewed for accuracy. However, not all the corrections arising from this review have been implemented on the CCR at the present time.

At present rates for Quebec Census Division 81, Communauté-Urbaine-de-l'Outaouais, include patients treated exclusively in Ontario only for the period 1992 to 1995 and therefore are expected to be about 10% lower than the actual values.

CD boundaries in the NWT and Nunavut follow 2001 boundaries since this corresponds to the new NWT and Nunavut boundaries and CD population data published by Statistics Canada. The only difference is Holman Hamlet, NWT in 1996 CD 08 is included in CD 07. Murray Township, in Ontario 1996 CD 14, was amalgamated into Quinte West in CD 12 as of 1998, so it is included with CD 12 for these results.

Disease Groupings

Disease groupings for mortality follow the International Classification of Diseases (ICD) coding system created by the World Health Organization (WHO), 9th or 10th revision. Disease groupings for cancer incidence follow the International Classification of Diseases for Oncology (ICDO) 3rd edition. Codes for malignant cancers are behaviour code /3. Rates presented here for all cancers exclude basal and squamous skin cancers, as is frequently the case with cancer surveillance data, since non-melanoma skin cancer is difficult to register completely. As of the August 2006 data release, rates presented include in situ bladder cancers.

Interpretation

The data provided here are for public use but care must be taken in interpreting any results. If someone has specified a younger group or a smaller province/area for a rare cancer, the year to year percent variation will be greater than for all age groups combined or all provinces combined, etc. due to the smaller number of cases. Any sudden changes from year to year could be due to random fluctuations and not a real trend in the data. As with other epidemiological information, mapped data may indicate an association but should not be interpreted as proof of a causal association. The data presented on this website provide no indication of the time sequence between cause and effect. Also, variations in cancer incidence may be a result of differences in cancer screening and registration practices, in addition to lifestyle or environmental factors. If you have any questions, or for assistance in interpreting the data, please contact the CCDPC.

When comparing the provinces with the largest populations to Canadian rates, there is a difficulty with the statistical comparisons, since these areas contribute a large proportion of the Canadian rates. As a result, the rates are not independent, and the tests of significance are conservative. That is, a larger difference than the nominal value is required to achieve statistical significance.

Cells with a count of less than 5 have been suppressed.

The symbol (r.d.) denotes data that has been suppressed to avoid residual disclosure.

For more information on Canadian Cancer Surveillance On-Line or other aspects of the Centre for Chronic Disease Prevention and Control, please click on the Contact button below. For Statistics Canada or the Public Health Agency of Canada main page, click on the logos on the main page.

Portions of the Canadian Cancer Incidence Atlas were modified for the site-specific descriptions provided in other sections of this website.

References

Swift MB. Simple confidence intervals for standardized rates based on the approximate bootstrap method. Stat Med 1995; 14:1875-88.

Ury HK, Wiggins AD. Another shortcut method for calculating the confidence interval of a poisson variable (or a standardized mortality ratio). Am J Epidemiol 1985; 122:197-98.


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Last Updated: 2006-12-18