Data source: BC Ministry of Health
April 1, 1985 onward (calendar year)
Data on discharges, transfers and deaths of in-patients and day surgery patients from acute care hospitals in BC.
All Canadian hospitals (except those in Quebec) submit their separations records directly to the Canadian Institute of Health information (CIHI) for inclusion in the Discharge Abstract Database (DAD). The database contains demographic, administrative and clinical data for hospital discharges (inpatient acute, chronic, rehabilitation) and day surgeries. A provincial data set, including various CIHI value-added elements (such as case mix groups, and resource intensity weights) is released on a monthly basis to the respective Ministries of Health. The DAD data files which Population Data BC receives include the CIHI variables. Population Data BC receives these data once per year.
- Fields available
Both Core and Non-Core fields are available for this data set.
Core vs. Non-Core Data
Core Data: Some data available through PopData and the HDP are ‘Core Data’. Core Data are data identified by the data provider as 'Safe Data' and eligible for pre-approved release, with the exception of PharmaNet data. Core Data includes commonly-requested data columns, but not necessarily all of the columns available in a data set. For example, some Core Data fields, such as geography or organisational codes, have been suppressed for increased privacy.Please note that the overall data access request is subject to meeting ALL of the Five SAFEs requirements, not just the Safe Data component. For more detail on the Five SAFEs, visit the HDP website.
Non-Core Data: Non-Core Data are data NOT identified by the data provider as 'Safe Data' and thus are NOT eligible for pre-approved release. Access to Non-Core Data follows the usual processes and will not follow expedited review procedures.
For the majority of DARs, requesting access to Core Data may make the data access approval process quicker and reduce the wait time for data access. It may also reduce the need for time-consuming data amendments related to a request for additional data fields or changes to study populations.
- Discharges, transfers and deaths of in-patients and day surgery patients (e.g. those undergoing scope procedures, cataract procedures, or other procedures requiring operating room time) from acute care hospitals.
- Data on BC residents who are admitted to a hospital in another province or territory are included in the DAD data. Also included in the data files are data on non-BC residents who are admitted to a BC hospital, however these data are usually excluded from extractions for research projects.
- The data include some records indicating the level of care is "extended". For the most part, these records refer to people who are in long-term care facilities that are attached to an acute care facility and should be excluded from analyses.
- Data on abortion procedures, including those conducted in concert with other procedures, are only available by special request. Requests must demonstrate how Therapeutic Abortion (TA) data is required to fulfill the research objectives by providing a strong rationale. The Ministry of Health will review requests and make a decision on release according to existing policy on a case-by-case basis. This is in accordance with the BC Freedom of Information and Protection of Privacy Act article 22.1.
- Visits to emergency rooms/departments are not recorded in the hospital files, though admissions to acute care via the emergency room are noted in the "entry code" field. The report by McKendry et al, 2002 provides more information on various methods for identifying emergency users.
- Outpatient services like x-rays or blood work are not included in the hospital data.
- Quality/accuracy of information/field coding source
The centralized data processing of the DAD records done by the Canadian Institute of Health information (CIHI) results in increased efficiency and standardization among the participating provinces.
- Data changes over time
- Beginning in 1996/97, the mother's personal health number (PHN) was recorded on a baby's discharge record, so it became possible to link mothers and babies in the hospital files.
- The format of the data changed significantly in 2001/02. Part of this change was due to the switch in BC from coding diagnoses in ICD9 codes to ICD10-CA codes, and from coding procedures/interventions in CCP procedure codes to CCI intervention codes. Beginning in 2001/02, some of the data fields have different names but the same meaning, and some fields may have the same name but contain subtly different data. Population Data BC has standardized the data fields and names across the years where possible.
- From 2001/02 to 2006/07, i.e. until all provinces in Canada were coding in ICD10-CA and CCI, CIHI was providing both the originally coded diagnosis codes and intervention codes (i.e. ICD10-CA and CCI for BC) and back-coded versions of these codes (i.e. ICD9/CCP codes) in the DAD files. This stopped as of 2007/08.
- Also as of April 2007, CIHI has redeveloped its acute care inpatient grouping methodology. The new CMG+ methodology is built on ICD10-CA/CCI activity and cost data and replaces the CMG/Plx methodology. CMG+ takes advantage of the increased specificity of the ICD10-CA/CCI classification standards and features several modifications and enhancements.
- Important additional information
These data files are grouped into fiscal years by separation date, not the date of admission.
- Several references are available on the CIHI web site (www.cihi.ca) on the impact of CIHI's acute-care inpatient grouping methodology switch, including "Coping with the Introduction of ICD10-CA and CCI: Impact of New Classifications Systems on the Assignment of Case Mix Groups/Day Procedure Groups using Fiscal 2001/2002 Data" and "CMG+ Tool Kit: Transitioning to the new CMG+ Grouping Methodology".
- McKendry R, Reid RJ, McGrail KM, Kerluke KJ. Emergency Rooms in British Columbia: A pilot project to Validate Current Data and Describe Users. Vancouver (BC): Centre for Health Services and Policy Research; December 2002.