Technical Note

30 Day Stroke In-hospital Mortality

Unit of Analysis:

  • The unit of analysis is an "Episode of care". An episode of care refers to all contiguous in-patient acute care hospitalizations. For episodes with transfers within or between facilities, transactions were linked regardless of diagnoses. To construct an episode of care a transfer is assumed to have occurred if admission to an acute care institution occurs on the same day as or prior to discharge from another in-patient hospitalization.

Denominator (Index Episode)

Inclusion Criteria:

    1. Stroke1 (ICD-10-CA: I60-I64; ICD-9CM: 430-432; 433-434 with fifth digit of 1; 436) is coded as MRDx but not also as a diagnosis type (2); or
    2. Where another diagnosis is coded as MRDx and also a diagnosis type (2), and a diagnosis of Stroke is coded as a type (1), or ; or
    3. Where rehabilitation (ICD-10: Z50.1, Z50.4-Z50.9; ICD-9CM: V57) is coded as MRDx and Stroke as a type (1), or .
  1. Admission between April 1 and March 1 of the following year (period of case selection ends March 1 to allow for 30 days of follow-up)
  2. Age at admission between 20 and 105 years
  3. Gender recorded as male or female
  4. Admission to an acute care institution
  5. Admission category recorded as urgent/emergent
  6. Canadian resident

Exclusion Criteria:

  1. Records with an invalid Health Card Number
  2. Records with an invalid date of birth
  3. Records with an invalid admission date or time
  4. Records with an invalid discharge date or time
  5. Records with a stroke admission within one year prior to the admission date of the index episode
  6. Records where the stroke coded as most responsible is also coded as a post-admission diagnosis (diagnosis type (2))


The numerator is a subset of the denominator meeting the following condition:
All cause in-hospital death within 30 days of admission for stroke.

1 Cerebral infarctions due to thrombosis/embolism of precerebral arteries (ICD-10-CA: I63.0, I63.1, I63.2; ICD-9CM: 433 with fifth digit of 1) cannot be uniquely identified in ICD-9, therefore current definition is not recommended for ICD-9 coding system.