Table 3.

Cox regression analysis. Risk of revision due to deep infection for all TKA patients in four different procedure duration groups

					Cox regressionc
					Unadjusted		Adjusted
Procedure duration	No of TKA	No of revisionsa	K-M 1y %b	K-M 4y %b	HR (95% CI)	p-value	HR (95% CI)	p-value
						0.01d		0.03d
<75	5680	48	0.60	0.89	1		1
75-89	6238	54	0.58	0.85	1.1 (0.7 - 1.5)	1.0	1.0 (0.7 - 1.4)	0.9
90-109	8659	91	0.63	1.01	1.2 (0.9 – 1.7)	0.3	1.1 (0.8 – 1.6)	0.5
≥110	7685	118	0.91	1.38	1.8 (1.3 – 2.5)	0.001	1.5 (1.0 – 2.1)	0.03

^aNumber of revisions due to deep infection (n = 311)

^bKaplan-Meier estimated proportion of revisions due to deep infection at 1 and 4 years follow-up

^cUnadjusted and adjusted Hazard ratios (HR) estimated with the Cox proportional hazards model (adjusted for sex, age, diagnosis, ASA classification and perioperative complications

^dOverall test for group differences