Assessment of the effectiveness of weight-adjusted antibiotic administration, for reduced duration, in surgical prophylaxis of primary hip and knee arthroplasty

Table 2 Demographic information for patients treated with the old regime and new regime of perioperative antibiotic prophylaxis (complete data)

	Old regime, n (%)	New regime, n (%)
	n = 310	n = 458
Age (mean ± SD)	67.5 ± 10.9 yr	67.0 ± 10.5 yr
Gender (male)	132 (42.6)	165 (36.0)
Weight (kg; mean ± SD)	84.82 ± 20.9	87.73 ± 22.3
Weight > 120 kg	19 (6.1)	44 (9.6)
Operation performed
Total hip arthroplasty	124 (40.0)	198 (43.2)
Total knee arthroplasty	186 (60.0)	260 (56.8)
Comorbidities
ASA grade
1	5 (1.6)	12 (2.6)
2	154 (49.7)	212 (46.3)
3	148 47.7)	227 (50.0)
4	3 (1.0)	7 (1.5)
Diabetes mellitus
Yes	49 (15.8)	48 (10.5)
No	261 (84.2)	410 (89.5)
Anticoagulation on admission
Yes	27 (8.7)	29 (6.3)
No	283 (91.3)	429 (93.7)
Antibiotic prophylaxis
Cefazolin	342 (50.7)	449 (98.0)
Clindamycin	11 (1.6)	8 (1.7)
Vancomycin	1 (0.1)	1 (0.3)
Dose appropriate for weight?
Yes	340 (50.3)	458 (100)
No	13 (2.0)	0 (0.0)

ASA: American society of anaesthesiology.