Hospital Standardized Mortality Ratio

The hospital standardized mortality ratio (HSMR) is an important measurement tool for hospitals and health regions that compares a hospital's death rate with the overall overage rate. When tracked over time the HSMR indicates how successful hospitals or health regions have been in reducing inpatient deaths and improving care. HSMR helps consumers indirectly by providing hospital with a starting point to access mortality rates and identify areas for performance improvement.

CIHI has made HSMR results public only for "eligible" hospitals - those with more than 2,500 HSMR cases. It has not released results for hospitals, like ours, with less than 2,500 HSMR cases in any of the reporting years because low numbers make the results less stable and, therefore, less reliable.

Ontario's hospitals are among the most accountable anywhere, and our hospital takes a great deal of pride in how open and transparent we are to the people we serve. The purpose of HSMR is to show statistically stable and reliable information.

We encourage the public to refer to the LHIN-Level result, which can give you an indication of performance on this particular indicator in this region.

HSMR results for the LHIN may be accessed by clicking here.

What is HSMR?

The hospital standardized mortality ratio (HSMR) is a measure of patient safety that compares a hospital's mortality rate with a national standard. It is used by many hospitals worldwide to assess and analyze mortality rates and has been proven useful in identifying areas that can be changed to improve patient safety and the quality of care.

HSMR gives hospital administrators and health providers a snapshot of a hospital’s performance at a given time and must be viewed in context with other indicators to help track progress over time.

Measuring compliance rates

HSMR is a ratio of "observed" to "expected" deaths, multiplied by 100. A ratio greater than 100 means more deaths occurred than expected, while a ratio less than 100 suggests fewer deaths occurred than expected.

Observed Deaths x 100
Expected Deaths

  • HSMR is based on diagnosis groups that account for 80% of deaths
  • HSMR is adjusted for factors affecting mortality (e.g. age, sex, length of stay)


HSMR rate at TADH for 2017/18: 100