ssiexh38-40.htm

Exhibit 38. Results of logistic regression using the derivation dataset for only total hip surgery

Variable	Estimate	tValue	Probability
Intercept	-3.15016	-1.31103	0.19127
Age	-0.02436	-1.36677	0.17172
Chronic lung disease	0.717234	1.299857	0.19365
Emergency surgery	1.667783	2.711989	0.00669
No. of procedures	0.647188	2.857793	0.00442
Postop admission	1.502892	2.895868	0.00379
Postop hemoglobin	-0.26253	-1.52152	0.12890
Preop hemoglobin	0.013404	0.231	0.82005
Surgery duration	0.007371	2.714224	0.00665

Postop = postoperative; Preop = preoperative.

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Exhibit 39. Results of logistic regression using the validation dataset for only total hip surgery

Variable	Estimate	tValue	Probability
Intercept	-5.30978	-2.3102	0.02089
Age	-0.01718	-1.01601	0.30962
Chronic lung disease	1.181684	2.524745	0.01158
Emergency surgery	2.01501	3.420056	0.00063
No. of procedures	-0.58576	-0.61154	0.54084
Postop admission	1.962564	3.988843	0.00007
Postop hemoglobin	0.079368	0.560087	0.72071
Preop hemoglobin	0.019021	0.361141	0.44228
Surgery duration	0.002467	1.890769	0.05866

Postop = postoperative; Preop = preoperative.

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Exhibit 40. Results of logistic regression using the combined dataset for only total hip surgery

Variable	Estimate	tValue	Probability
Intercept	-4.28495	-2.91129	0.00361
Age	-0.02085	-1.74905	0.08028
Chronic lung disease	0.930147	2.645746	0.00815
Emergency surgery	1.730828	4.182002	0.00003
No. of procedures	0.410227	1.931115	1.931115
Postop admission	1.728514	4.971104	0.00000
Postop hemoglobin	-0.09155	-0.89798	0.36925
Preop hemoglobin	0.014634	0.464605	0.64256
Surgery duration	0.003186	2.997669	0.00272

Postop = postoperative; Preop = preoperative.

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Current as of December 2012

Internet Citation: ssiexh38-40.htm. December 2012. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/findings/final-reports/ssi/ssiexh38-40.html