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

• If the SSI SIR > 1, then the facility has a higher rate of infection than the national benchmark
• If the SSI SIR < 1, then the facility has a lower rate of infection than the national benchmark
• If the SSI SIR = 1, then the facility has the same rate of infection as the national benchmark
• NOTE: If the Predicted number of infections is less than 1, then there is not enough data to calculate a SIR.