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 post-census age distribution of the Canadian population, based on unrounded counts and five-year age groups. Previous versions of the data tool used the 2011 post-census age distribution. 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.

Provincial and Territorial Notes:

• Nova Scotia data among individuals aged 1–19 are excluded.
• Nunavut data are excluded before 2005–2006.
• Newfoundland and Labrador data are excluded before 2008–2009.
• Yukon data are excluded before 2010–2011.
• New Brunswick data were not available.
• 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 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.
• On February 1, 2023, British Columbia (BC) implemented a new Longitudinal Family Physician (LFP) payment model billed through BC’s Medical Services Plan (MSP) database whereby family physicians can now bill for time spent with patients. MSP records for health encounters billed under the new model include use of a placeholder diagnostic code that is not valid for Canadian Chronic Disease Surveillance System (CCDSS) case definitions. Implementation of the LFP model is not anticipated to significantly impact incidence estimates, however indirect effects of the new billing model cannot be ruled out. Data should therefore be interpreted with caution until further validation is completed.
• BC’s LFP payment model introduced a new MSP service code that was not included in the previous CCDSS version. As a result, records billed under this new code in February and March 2023 were missed. The current CCDSS version retrospectively includes these records; therefore, estimates for fiscal year 2022–2023 may be higher for some conditions compared to estimates from the previous version.

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.