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Exhibits 65 to 67

Exhibit 65. Results of logistic regression using the derivation dataset for only total knee surgery

VariableEstimatetValueProbability
Intercept-6.27-3.130.0025
Charlson score*0.322.030.0423
General anesthesia-0.48-1.220.2231
Male0.902.200.0280
History of MRSA1.492.690.0071
Postop admission2.974.830.0000
Postop hematocrit0.060.860.3922
Preop hematocrit0.090.570.5742
Preop hemoglob-0.50-1.090.2835
Surgery duration0.001.250.2104

*Additional Intermountain risk factor.

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Exhibit 66. Results of logistic regression using the validation dataset for only total knee surgery

VariableEstimatetValueProbability
Intercept-3.76-2.230.0256
Charlson score*-0.51-1.750.0793
General anesthesia0.531.330.1819
Male0.601.700.0896
History of MRSA2.124.450.0000
Postop admission1.744.660.0000
Postop hematocrit-0.01-0.100.9173
Preop hematocrit0.060.540.5918
Preop hemoglob-0.37-1.110.2670
Surgery duration0.011.640.1007

*Additional Intermountain risk factor.

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Exhibit 67. Results of logistic regression using the combined dataset for only total knee surgery

VariableEstimatetValueProbability
Intercept-4.57-3.790.0002
Charlson score*0.030.190.8475
General anesthesia0.110.430.6692
Male0.732.750.0059
History of MRSA1.765.010.0000
Postop admission2.156.990.0000
Postop hematocrit0.020.460.6493
Preop hematocrit0.040.370.7176
Preop hemoglob-0.33-1.080.2875
Surgery duration0.001.780.0759

*Additional Intermountain risk factor.

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Current as of December 2012
Internet Citation: Exhibits 65 to 67. December 2012. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/findings/final-reports/ssi/ssiexh65-67.html