Table 3.

Univariate analysis of intra/postoperative risk factors

Characteristics	With AKI (n=34)	AKI prevalence	p-value	Odds ratio (95% CI)
Procedure	Hip (20/187)	10.7%	0.10*	1.8 (0.9–3.7)
	Knee (14/226)	6.2%
Intraoperative fluids	<1l (20/211)	9.5%	0.54*
	1–2l (9/145)	6.2%
	>2l (5/57)	8.8%
Intraoperative NSAIDs	No (33/370)	8.9%	0.24**
	Yes (1/43)	2.3%
Antibiotics	Teicoplanin/gentamicin or other (19/202)	9.4%	0.40*
	Cefuroxime (15/211)	7.1%
Tranexamic acid	No (3/28)	10.7%	0.62*
	Yes (31/385)	8.1%
Transfusion	No (32/387)	8.3%	0.92*
	Yes (2/26)	7.7%
Postoperative fluids	No / <1l (22/339)	6.5%	0.006*	2.8 (1.3–5.9)
	>1l (12/74)	16.2%
Postoperative NSAIDs	No / stopped preoperatively (23/263)	8.7%	0.54**
	Yes (continued preoperative NSAID) (6/82)	7.3%
	Yes (commenced new NSAID) (3/56)	5.4%
	Yes (continued preoperative NSAID + commenced new NSAID) (2/12)	16.7%

AKI = acute kidney injury; CI = confidence interval; NSAID = non-steroidal anti-inflammatory drug

*chi-squared test; **Fisher’s exact test