The purpose of this record linkage project is to better understand and quantify the association between risk factors (behavioural, socio-economic, and environmental), hospital utilization and health outcomes at the individual and population level among household dwelling Canadians.
This record linkage project brings together health survey data from the Canadian Community Health survey (CCHS) annual component for 2000 to 2011, the Canadian Community Health Survey Focus Content for Mental Health and Wellbeing (2002), Nutrition (2004) and Healthy Aging (2008), and the Discharge Abstract Database 1999/2000 through 2012/2013. Statistics Canada does not have Quebec hospitalization data as part of its data holdings, and thus Quebec data are not included in the linked datasets.
Canadian Community Health Survey
The annual component of the Canadian Community Health Survey (CCHS) collects cross-sectional information about the health, health behaviours and health care use of the non-institutionalized household population aged 12 or older.The survey excludes full-time members of the Canadian Forces and residents of reserves and some remote areas, together representing about 4% of the target population.
The CCHS focus content surveys are designed to provide cross sectional, provincial level results on specific focused health topics.Three focus content files were used in this linkage project. The CCHS Mental Health and Well-being (2002) collected information about mental disorders, mental health system use, and disability associated with mental health problems among the household population aged 15 and older. The CCHS Nutrition (2004) collected information about dietary intake, nutritional well-being and their key determinants. The CCHS Healthy Aging (2008) collected information among the household population aged 45 and over. This survey focused on the various factors that impact healthy aging such as physical activity, use of health care services, social participation, and work and retirement transitions.
The following is a list of CCHS annual files, and focus content files that were used in this linkage project and which are available to researcher in the RDC. Only those respondents who agreed to share and link their survey results were included.
- CCHS 1.1 (2000 to 2001)
- CCHS 2.1 (2003 to 2004)
- CCHS 3.1 (2005 to 2006)
- CCHS 2007
- CCHS 2008
- CCHS 2009
- CCHS 2010
- CCHS 2011
- CCHS Mental Health and Well-being (2002)
- CCHS Nutrition (2004)
- CCHS Healthy Aging (2008)
The CCHS questionnaires are available on the Statistics Canada website or through your RDC Analyst. Non-confidential information about the CCHS is available through the data liberation initiative, through your local RDC Analyst, or can be requested through Health Statistics Division client services (firstname.lastname@example.org).Once approval to access the linked files has been granted, user guides, questionnaires and other confidential documentation will be accessible to approved researchers in the RDC.
The CCHS records eligible for linkage were respondents residing outside the province of Quebec, who consented to share their survey information with provincial and federal ministries of health and to link their responses to administrative data. Approximately 84.7% of CCHS respondents residing outside the province of Quebec agreed to share and link their data; results vary across survey years.
Discharge Abstract Database (DAD)
The Discharge Abstract Database (DAD) captures administrative, clinical and demographic information on hospital discharges (including in-hospital deaths, sign-outs and transfers) from all provinces and territoriesFootnote 1, except Quebec. Over time, the DAD has also been used to capture data on day surgery procedures, long-term care, rehabilitation and other types of care. Hospitals in Manitoba started submitting their records to DAD from April 1, 2004. Throughout the fiscal years that are covered in the linkage, there were openings, closure and mergers of institutions.
In the DAD, jurisdiction-specific instructions for collection of data elements evolve over time. Collection of each data element may be mandatory, mandatory if applicable, optional or not applicable. Collection requirements can vary by jurisdiction and by data year.
Researchers will find the listings of DAD data elements under the heading “Data Elements” at the DAD Metadata website.1 Please note that not all DAD data elements are included in the RDC DAD datasets for this linkage project. A list of available DAD variables is contained in user guide for the linked dataset. The documents on the website include information on mandatory versus optional collection status for each data element by jurisdiction, which is key to understanding coverage of data elements in the DAD.
For this record linkage, DAD data from fiscal years 1999/2000 through 2012/2013 were included, representing 49,098,773 hospital transactions.
File structure, layout
All variables from the CCHS share files are available for analysis. Please see appropriate data dictionaries for relevant CCHS cycles.
The DAD is an event based file meaning that there will be more than one record for a person who was hospitalized more than once in the same fiscal year. During the linkage process, all DAD records belonging to one person were identified by combining the variables sampleid and personid for that person. This combination of variables allows the researcher to identify individuals with multiple hospitalizations. Researchers can then choose to use the DAD file as an event based file (each row of data represents a hospitalization) or a person based file (each row of data represents an individual).
In order to use the file as a person based file, the researcher must transform the data to include all hospital information for one person as one record (one row on the data file).