Data are collected from each patient’s chart at the time of discharge from hospital and are recorded on an abstract provided by Canadian Institute for Health Information (CIHI). The abstract collects information on the patient and the nature of their stay. One abstract is completed for each separation (stillbirth, death, discharge) from the hospital.
The main diagnostic code gives the primary reason for the hospital stay or “most responsible diagnosis” (MRD). A second set of codes, external cause or “e-codes”, are used to classify the environmental events, circumstances and conditions that cause an injury (e.g. motor vehicle injury). While the e-codes are the principal means for classifying injury deaths, they are not used as a MRD for hospitalizations so they need to be examined separately.
The data source contains discharge records, not admissions. The data are reported for completed cases only. Hospitals do not report on cases that are still being treated. The data represent the number of discharges, not the number of people.
Since a person may not be hospitalized, or may be hospitalized several times for the same disease or injury event, or discharged from more than one hospital (when transferred) for the same injury event, hospitalization data provide only a crude measure of the prevalence of a cause.
Data are influenced by factors that are unrelated to health status such as availability and accessibility of care, and administrative policies and procedures. This may influence comparisons between areas and over time.