The document defines the Standardized Mortality Ratio as the ratio of observed deaths to predicted deaths in an ICU over a specified time period. It is calculated by taking the actual number of deaths in the ICU divided by the predicted number of deaths estimated using a risk-adjustment model like APACHE, SOFA, SAPS, or PRISM and multiplying by 100. A SMR below 1 indicates fewer observed deaths than predicted, a SMR of 1 means the number was equal, and above 1 means more observed deaths than predicted. The APACHE II score introduced in 1985 is referenced as a common risk-adjustment model used to estimate predicted mortality.

1. STANDARDIZED
MORTALITY RATIO
Israt sadia
MBBS, Mphil.
Infection Control Departement
Labaid hospital

2. Standardized Mortality Ratio
• It is the ratio of the Observed or actual mortality and the
predicted mortality for a specified time period.
• It requires an estimate of predicted mortality rate using a
scoring system like APACHE, SOFA, SAPS,MPM or PRISM.
• Actual death in ICU/ Predicted deaths in ICU x100 =
• SMR < 1.0 indicates there were fewer than expected
deaths in the study population
• SMR = 1.0 indicates the number of observed deaths
equals the number of expected deaths in the study
population
• SMR >1.0 indicates there were more than expected
deaths in the study population (excess deaths)

3. APACHE score
•Acute Physiologic Assessment and Chronic
Health Evaluation II (APACHE II) score
introduced in 1985.
•https://www.mdcalc.com/apache-ii-score#evidence

6. •APACHE II Score ≥ 20 in 1 patient = 1 predicted
death