TABLE 4.

PJI rate according to different antibiotic prophylaxis and different subgroups of patients

Patient subgroup (no. of patients) and PJI subgroup	No. (%) of patients with PJI		P valuea
	C group (n = 995)	CT group (n = 791)
BMI of <30 kg/m2 (n = 960)b
PJI	13 (2.6)	8 (1.8)	0.383
PJI due to GPc	9 (1.8)	6 (1.3)	0.558
BMI of ≥30 kg/m2 (n = 822)b
PJI	22 (4.5)	2 (0.6)	0.001
PJI due to GP	20 (4.1)	1 (0.3)	0.001
Duration of surgery of <105 min (n = 1,330)
PJI	21 (3.0)	8 (1.3)	0.037
PJI due to GP	20 (2.8)	5 (0.8)	0.007
Duration of surgery of ≥105 min (n = 456)
PJI	14 (4.9)	2 (1.2)	0.037
PJI due to GP	9 (3.1)	2 (1.2)	0.223

^aBoldface values indicate statistically significant differences.

^bIn 4 cases the BMI was not available.

^cGP, Gram-positive microorganism.