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Risk Adjustment Factors Included in the SIR
MRSA Bacteremia LabID
MRSA Bacteremia LabID Event Risk Adjustment (LTACHs)
The number of predicted MRSA bacteremia Lab ID events under the 2022 baseline is calculated using a negative binomial regression model and is risk adjusted based on the following variables found to be statistically significant predictors of MRSA bacteremia incidence. Information about the statistical properties of NHSN risk adjustment models, including how the number of predicted events is calculated, is available in NHSN’s Guide to the SIR (2022 baseline).
| Parameter | Parameter Estimate | Standard Error | P-value |
| Intercept | -11.1269 | 0.3508 | <0.0001 |
| Proportion of admissions on hemodialysis1: ≥0.218 | 1.9602 | 0.3352 | <0.0001 |
| Proportion of admissions on hemodialysis1: 0.075-0.217 | 1.2618 | 0.3272 | 0.0001 |
| Proportion of admissions on hemodialysis1: 0-0.074 | REFERENT | – | – |
| Average length of stay1: ≥31.9 days | 0.5414 | 0.1993 | 0.0066 |
| Average length of stay1: 1-31.8 days | REFERENT | – | – |
| Total number of beds1: ≥69 | 0.4252 | 0.1599 | 0.0079 |
| Total number of beds1: 1–68 | REFERENT | – | – |
Footnotes:
1 Proportion of admissions on hemodialysis, total # of beds, and average length of stay are reported or calculated from values reported on the Annual LTACH Survey. Proportion of admissions on hemodialysis is calculated as: # admissions on hemodialysis / total # of annual admissions. Average length of stay is calculated as: total # of annual patient days / total # of annual admissions.
1 Proportion of admissions on hemodialysis, total # of beds, and average length of stay are reported or calculated from values reported on the Annual LTACH Survey. Proportion of admissions on hemodialysis is calculated as: # admissions on hemodialysis / total # of annual admissions. Average length of stay is calculated as: total # of annual patient days / total # of annual admissions.
