Indicator Metadata

NameHospital Deaths (HSMR)
Short/Other Names

Hospital Standardized Mortality Ratio (HSMR)

Description

The ratio of the actual number of in-hospital deaths in a region or hospital to the number that would have been expected, based on the types of patients a region or hospital treats.

For further details, please see the General Methodology Notes.

InterpretationLower is better. The HSMR is most useful to follow a hospital’s performance over time.
HSP Framework Dimension

Health System Outputs: Appropriate and effective

Areas of Need

Getting Better

Geographic Coverage

All provinces

Reporting Level/Disaggregation

National, Province/Territory, Region, Facility

Indicator Results

Accessing Indicator Results on Your Health System: In Depth

Identifying Information
NameHospital Deaths (HSMR)
Short/Other Names

Hospital Standardized Mortality Ratio (HSMR)

Indicator Description and Calculation
Description

The ratio of the actual number of in-hospital deaths in a region or hospital to the number that would have been expected, based on the types of patients a region or hospital treats.

For further details, please see the General Methodology Notes.

Calculation: Description

The ratio of the actual number of in-hospital deaths to the expected number of in-hospital deaths, for conditions accounting for about 80% of inpatient mortality

Unit of Analysis: Hospitalization

Calculation: Geographic Assignment

Place of service

Calculation: Type of Measurement

Ratio

Calculation: Adjustment Applied

The following covariates are used in risk adjustment:
For each HSMR diagnosis group, the HSMR logistic regression models are fitted with age, sex, length-of-stay (LOS) group, admission category (urgent and elective), comorbidity (Charlson Index Score) group and transfers as independent variables.

Calculation: Method of Adjustment

Logistic regression

Denominator

Description:
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 (2012–2013)
Inclusions:
1. Discharge between April 1 of a given year and March 31 of the following year

2. Admission to an acute care institution (Facility Type Code = 1)

3. Discharge with diagnosis group of interest (i.e., one of the diagnosis groups that account for about 80% of in-hospital deaths, after excluding patients receiving palliative care)

4. Age at admission between 29 days and 120 years

5. Sex recorded as male or female

6. Length of stay of up to 365 consecutive days

7. Admission category recorded as urgent/emergent or elective (Admission Category Code = U or L)
Exclusions:
1. Cadavers or stillborns (Discharge Disposition Code = 08 or 09)

2. Self sign-outs or did not return from a pass (Discharge Disposition Code = 06 or 12)

3. Records with most responsible diagnosis (MRDx) of palliative care (ICD-10-CA: Z51.5). For Quebec data: records where Z51.5 coded as MRDx, or cancer (C00–C97) coded as MRDx and Z51.5 coded in any secondary diagnosis field

4. Medical assistance in dying (MAID) cases for fiscal years 2016–2017 to 2017–2018:

  • Discharge disposition = 07 (in-hospital death) AND one of the following:
    – Prefix = J in any field; OR
    – 3 CCI codes: 1.ZZ.35.HA-P7, 1.ZZ.35.HA-P1, 1.ZZ.35.HA-N3 (all present on the same abstract)
Numerator

Description:
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

Background, Interpretation and Benchmarks
Rationale

The HSMR is a performance indicator that allows hospitals to measure and monitor their progress in quality of care.

Ever since the HSMR measure was first developed and disseminated by CIHI, many hospitals and health providers across Canada have been using it as part of their ongoing efforts to improve care.

The HSMR can be used to track the overall change in mortality resulting from a broad range of factors, including changes in the quality and safety of care delivered.

Interpretation

Lower is better. The HSMR is most useful to follow a hospital’s performance over time.

HSP Framework Dimension

Health System Outputs: Appropriate and effective

Areas of Need

Getting Better

Targets/Benchmarks

Not applicable

References

Alexandrescu R, Jen MH, Bottle A, Jarman B, Aylin P. Logistic versus hierarchical modeling: an analysis of a statewide inpatient sample. J Am Coll Surg 2011;213(3):392-401.

Bottle A, Jarman B, Aylin P. Hospital standardized mortality ratios: sensitivity analyses on the impact of coding. Health Serv Res 2011;46(6pt1):1741-1761.

Bottle A, Jarman B, Aylin P. Strengths and weaknesses of hospital standardised mortality ratios. BMJ 2011;342:c7116.

Breslow NE, Day NE. Statistical Methods in Cancer Research: Volume II: The Design and Analysis of Cohort Studies. Lyon: International Agency for Research on Cancer; 1987.

Jarman B, Gault S, Alves B et al. Explaining differences in English hospital death rates using routinely collected data. BMJ 1999;318(7197):1515-1520.

Jarman B, Bottle A, Aylin P, Browne M. Monitoring changes in hospital standardised mortality ratios. BMJ 2005;330(7487):329.

Quan H, Li B, Couris CM et al. Updating and validating the Charlson comorbidity index and score for risk adjustment in hospital discharge abstracts using data from 6 countries. Am J Epidemiol 2011;173(6):676-682.

Availability of Data Sources and Results
Data Sources

DAD, HMDB

Available Data Years

Type of Year:
Fiscal
First Available Year:
2012
Last Available Year:
2016

Geographic Coverage

All provinces

Reporting Level/Disaggregation

National, Province/Territory, Region, Facility

Result Updates
Update Frequency

Twice a year

Indicator Results

Web Tool:
Your Health System: In Depth
URL:
Accessing Indicator Results on Your Health System: In Depth

Updates

Changes to the HSMR methodology, implemented in February 2015, include the following:

1. HSMR results are calculated with an updated baseline using 2012–2013 data. The previous baseline was calculated using 2009–2010 data.

2. The statistical test of significance is based on comparing results with the national average (as opposed to 100).

Quality Statement
Caveats and Limitations

Medical assistance in dying (MAID) was decriminalized in Canada with the enactment of Bill C-14 in June 2016. MAID cases are excluded from HSMR calculations for all DAD-submitting provinces and territories. It is not possible to exclude MAID cases from Quebec results due to differences in data collection. The impact of the differences of MAID exclusion is not fully known but is estimated to have a small effect on interprovincial comparability.

Trending Issues

Not applicable

Comments

The average experience of Canadian hospitals is set at 100 and is based on data collected in 2012–2013. HSMR results are compared against the current national average. An HSMR above the national average indicates that the hospital’s mortality rate is higher than the average HSMR. An HSMR below the national average indicates that the hospital’s mortality rate is lower than the average HSMR.

Further information is available in the Technical Notes and other HSMR resources: https://www.cihi.ca/en/health-system-performance/quality-of-care-and-outcomes/hsmr

Indicator results are also available in