TABLE IV.

HRs for Different Risk Subgroups^*

Risk Group*	Training Cohort			Test Cohort
	Threshold	HR†	P Value	HR†	P Value
Periprosthetic joint infection
Low	0.0%	Reference	—	Reference	—
Intermediate	0.8%	1.8 (1.1 to 3.0)	0.01	1.6 (0.8 to 3.2)	0.1
High	1.3%	4.8 (3.2 to 7.3)	<0.001	3.5 (2.0 to 6.2)	<0.001
Dislocation
Low	0.0%	Reference	—	Reference	—
Intermediate	0.5%	1.8 (1.0 to 3.5)	0.05	2.0 (0.8 to 5.1)	0.1
High	0.8%	3.6 (2.0 to 6.5)	<0.001	3.5 (1.4 to 8.5)	0.005
Periprosthetic fracture
Low	0.0%	Reference	—	Reference	—
Intermediate	0.3%	2.5 (1.1 to 5.8)	0.03	2.3 (0.8 to 6.4)	0.1
High	0.5%	5.4 (2.7 to 10.6)	<0.001	4.4 (1.9 to 10.0)	<0.001
Death
Low	0.0%	Reference	—	Reference	—
Intermediate	0.5%	3.9 (1.5 to 10.1)	0.005	1.4 (0.4 to 5.0)	0.7
High	0.8%	21.3 (9.3 to 48.7)	<0.001	14.0 (5.6 to 35.3)	<0.001

^*For each outcome, the thresholds for low, intermediate, and high risk were defined using tertiles of the risk score distribution in the training data.

^†The values are given as the HR, with the 95% CI in parentheses.