Many patients admitted to Stanford Hospital & Clinics are very
sick with complicated medical conditions that decrease their chances
for survival. The "mortality ratio" compares patients'
actual mortality rates to their expected mortality rates—which take
into account the severity of a patient's illness. A lower score
mortality ratio means that more patients survived than were expected
due to the severity of their illnesses.
Our mortality ratio is excellent, particularly given the number of
severely ill, high-risk patients at Stanford Hospital &
Clinics. Stanford Hospital & Clinics' mortality ratio between
October 2007– September 2008 was 0.83 (red bar).
Our mortality ratio is below the benchmark of 0.93 (yellow bar).
This graph shows mortality ratios for the past two years. Stanford
Hospital and Clinics (red bar) has consistently performed at or lower
than the benchmark (yellow bar) and significantly better than
the standard (blue bar) where observed mortality equals the expected rate.
Explaining mortality ratio
Mortality ratios are quality data that compare patients' actual vs.
expected mortality rates, based on patients' illnesses.
Mortality ratio = Observed mortality / Expected mortality
Observed mortality is the number of patient deaths that occur
in the hospital.
Expected mortality is the predicted number of deaths in the
hospital based on the hospital's patients' levels of illness. Patients
who are very sick (higher severity of illness) have a higher expected
mortality rate. However, the expected mortality rate does not reflect
a hospital's quality of care. If two hospitals had patients with
exactly the same severity of illnesses, the hospitals' expected
mortality rates would be the same.
The standard ratio of 1.0 indicates that the observed
mortality rate equaled the expected mortality rate based on patients'
level of illness.