Logistic regression

Observed deaths, or actual number of in-hospital deaths that occurred in a hospital or region

Inclusions:
Same as for the denominator
Exclusions:
Same as for the denominator

Expected deaths, or number of deaths that would have occurred in a hospital or region had the mortality of these patients been the same as the mortality of similar patients across the country, based on the reference year (i.e. FY 2012-2013). Regional and facility HSMR results are based on where patients were treated, not where they lived.

Inclusions:

1. Discharge between April 1 of a given year and March 31 of the following year.
2. Admission to an acute care institution.
3. Discharge with diagnosis group of interest (that is, one of the diagnosis groups that account for approximately 80% of in-hospital deaths).
4. Age at admission between 29 days and 120 years.
5. Sex recorded as male or female. 
6. Length of stay up to 365 consecutive days.
7. Admission category is elective or emergent/urgent.
8. Ontario resident.

Exclusions:

1. Cadavers or stillborns.
2. Sign-outs (that is, discharged against medical advice).
3. Patients who did not return from a pass.
4. Neonates (age of admission less than or equal to 28 days).
5. Brain death as most responsible diagnosis code.
6. Records with most responsible diagnosis (MRDx) of palliative care (ICD-10-CA: Z51.5).