TABLE 4.

Multivariable Comparison of Outcomes Against Hospital Type^a

Outcome	Top-ranked hospitals vs ineligible hospitals			Non–top-ranked hospitals vs ineligible hospitals
	β coefficient	OR	95% CI	β coefficient	OR	95% CI
30-d postoperative adverse events	0.03	1.03	0.79-1.34	0.05	1.05	0.86-1.28
Mortality	0.02	1.02	0.52-2.00	–0.34	0.71	0.42-1.22
Pulmonary embolism	–0.04	0.96	0.62-1.48	–0.02	0.98	0.68-1.40
Deep vein thrombosis	–0.11	0.90	0.67-1.20	0.01	1.01	0.79-1.30
Wound infection	0.22	1.24	0.85- 1.83	0.17	1.19	0.87-1.63
Hemorrhage	0.64	1.90	1.29-2.79	0.39	1.47	1.08-2.02
Sepsis	–0.23	0.80	0.43-1.48	–0.03	0.97	0.60-1.57
Myocardial infarction	–0.11	0.90	0.49-1.65	0.09	1.10	0.67-1.78
30-d readmission	–0.05	0.95	0.78-1.17	–0.01	0.98	0.86-1.14
Length of stay	–0.05	/	–0.13 to 0.03	–0.01	/	–0.06 to 0.05
In-hospital cost	–0.63b	/	–1.10 to –0.16	–0.66b	/	–1.11 to –0.21

^aMultivariable logistic (30-day postoperative adverse event and 30-day readmission) and Poisson (length of stay and in-hospital cost) regression models controlled for patient characteristics including patient age, race, sex, zip code–level income, zip code–level percentage of high school graduation, patient comorbidities (congestive heart failure, cardiac arrhythmias, pulmonary circulation disorders, hypertension, paralysis, neurologic disorders, diabetes, renal failure, liver disease, arthritis, coagulopathy, obesity, weight loss, electrolyte disorders, blood loss, and drug abuse) and hospital characteristics including teaching status, volume of Medicare total knee arthroplasty, nurse-staffing ratio, ownership, hospital medical affiliation, and geographic location (rural or urban). CI = confidence interval; OR = odds ratio; / = odds ratios not calculated for LOS or cost.

^bP<.001.