Canadian Chronic Disease Surveillance System (CCDSS)

Context-Specific Notes:

• *Many CCDSS measures, such as chronic condition incidence, were influenced by the COVID-19 pandemic. Changes in such measures may be driven by multiple factors, including (but not limited to) differences in healthcare seeking behaviour, the availability and use of healthcare services, as well as true changes in health status. As such, CCDSS measures should be used cautiously when making inferences about population health during the COVID-19 pandemic. For the purposes of interpreting the estimates in this data tool, the COVID-19 pandemic period is defined as fiscal years 2020–2021 to 2022–2023. This timeframe aligns with the World Health Organization’s declaration of COVID-19 as a public emergency of international concern from January 30, 2020, to May 5, 2023. Guidance for data users on examining the impacts of the COVID-19 pandemic on CCDSS measures during the pandemic period can be accessed below.
• IMPORTANT CHANGE: Estimates are now age-standardized using the 2021 Canadian population, based on unrounded counts and five-year age groups. Previous versions of the data tool used the 2011 Canadian population. As a result, differences may be observed when comparing estimates across versions.

General Notes:

• Data suppression: Estimates are not reported when the counts are less than 10 or the coefficient of variation is greater than 33.3%.
• Due to periodic updates of the historical surveillance data, estimates for a particular condition and year may change over time, and may not be comparable to previous versions.
• Due to delays in the availability of source data used to update health registries in certain provinces and territories, mortality estimates may vary from one update to another, and may not be directly comparable across versions.

Provincial and Territorial Notes:

• Nunavut data are excluded before 2005–2006.
• Newfoundland and Labrador data are excluded before 2008–2009.
• Yukon data are excluded.
• Due to New Brunswick’s 2020 transition to ICD-10-CA codes in physician billing claims, continuity with historical health data has been disrupted, affecting the inclusion of conditions relying on physician billing claim data in the CCDSS. Options are being explored to expedite the reintegration of New Brunswick’s data in future releases.
• The modernization of the Quebec billing system for fee-for-service medical services by the Régie de l’assurance maladie du Québec (RAMQ) in 2016 has resulted in a decrease in the entry of diagnostic codes in the fee-for-service medical services file. Data for 2016–2017 and subsequent years should therefore be interpreted with caution, as a slight underestimation is suspected.
• The introduction of the Northwest Territories Electronic Medical Record (EMR) in 2016 resulted in more complete and consistent data. Data for 2016–2017 may be slightly underestimated compared to previous years due to the system transition. 
• Northwest Territories physician billing claim data were incomplete for 2021–2022, 2022–2023 and 2023–2024 and should therefore be interpreted with caution, as a slight underestimation is suspected.

Other Notes:

• These data were made possible through collaboration between PHAC and the respective provincial and territorial governments of British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, Prince Edward Island, Newfoundland and Labrador, Northwest Territories, Yukon, and Nunavut. No endorsement by the provinces and territories is intended or should be inferred. Provincial and territorial data were contributed to the CCDSS as of April 2025.