SIR - This is a ratio of the Observed number of infections to the Predicted number of infections.

1. If the SIR > 1, then the facility has a higher rate of infection than the national benchmark
2. If the SIR < 1, then the facility has a lower rate of infection than the national benchmark
3. If the SIR = 1, then the facility has the same rate of infection as the national benchmark
4. NOTE: If the Predicted number of infections is less than 1, then there is not enough data to calculate a SIR. For more information about the SIR, go to Understanding the Data.