. Author manuscript; available in PMC: 2021 Apr 27.

Published in final edited form as: J Orthop Trauma. 2020 Mar;34(3):113–120. doi: 10.1097/BOT.0000000000001715

TABLE 4.

Association Between Duration of Prophylactic Antibiotic Use and Deep SSI Stratified by Severity of Wound Contamination Based on Unadjusted, Adjusted, and Propensity Score–Stratified Models, N = 2400

Contamination	Antibiotic Use	Deep SSI (n = 163) n (%)	No Deep SSI (n = 2237) n (%)	Unadjusted		Adjusted		Propensity Score–Stratified
Contamination	Antibiotic Use	Deep SSI (n = 163) n (%)	No Deep SSI (n = 2237) n (%)	OR (95% CI)	P	OR (95% CI)	P	OR (95% CI)	P

Mild	> 72 h (n = 726)	43 (5.9)	683 (94.1)	1.20 (0.80, 1.81)	0.38	1.39 (0.92, 2.11)	0.12	1.35 (0.89, 2.05)	0.16
	≤ 72 h (n = 1123)	56 (5.0)	1067 (95.0)	1.0 (ref)		1.0 (ref)		1.0 (ref)
Moderate	> 72 h (n = 221)	17 (7.7)	204 (92.3)	0.85 (0.43, 1.70)	0.65	1.09 (0.53, 2.27)	0.81	1.17 (0.57, 2.43)	0.67
	≤ 72 h (n = 202)	18 (8.9)	184 (91.1)	1.0 (ref)		1.0 (ref)		1.0 (ref)
Severe	> 72 h (n = 61)	7 (11.5)	54 (88.5)	0.27 (0.10, 0.68)	0.006	0.20 (0.07, 0.60)	0.003	0.23 (0.08, 0.65)	0.005
	≤ 72 h (n = 67)	22 (32.8)	45 (67.2)	1.0 (ref)		1.0 (ref)		1.0 (ref)

Odds ratios (ORs), confidence intervals (CIs), and P values calculated using logistic regression. Percentages shown are row percents. Adjusted model includes Gustilo–Anderson wound type, days to definitive closure, country, and wound area. Propensity score–stratified model adjusts for propensity score stratum, days to definitive closure, and country.