Table 4.

Univariate model of factors associated with treatment failure^a

Variable	Value for group		OR (95% CI)	P value
	Treatment success (n = 34)	Treatment failure (n = 9)
Median age (yr) (IQR)	74 (69–77)	63 (59–77)	1.0 (0.9–1.0)	0.2
No. (%) of female patients	19 (83)	4 (17)	0.6 (0.1–2.8)	0.5
No. (%) of patients with knee arthroplasty	14 (93)	1 (7)	0.2 (0.02–1.6)	0.1
No. (%) of patients with index arthroplasty indication
Primary	28 (80)	7(20)	1 (ref)
Aseptic revision	5 (83)	1 (17)	0.8 (0.08–8.0)	0.8
Septic revision	1 (50)	1 (50)	4 (0.2–72.2)	0.3
Median no. of days of symptoms (IQR)	7 (2–14)	4 (1–7)	1.0 (0.9–1.1)	0.3
No. (%) of patients with infection classification of:
Early (≤90 days from implantation)	32 (78)	9 (22)	1 (ref)
Delayed (>90 days from implantation)	2 (100)	0
No. (%) of patients with polymicrobial infection	12 (75)	4 (25)	1.5 (0.3–6.5)	0.6
No. (%) of patients with causative microorganism
MRSA	16 (67)	8 (33)	9.0 (1.0–80.0)	0.049
MR-CNS	8 (89)	1 (11)	0.1 (0.01–0.9)	0.03
No. (%) of patients with no. of surgical debridements
2–3	30 (91)	3 (9)	1 (ref)
1	1 (25)	3 (75)	30.0 (2.3–386.3)	0.009
≥4	3 (50)	3 (50)	10.0 (1.4–73.3)	0.02
No. (%) of patients with liner changed	15 (83)	3 (17)	1.6 (0.3–7.4)	0.6
No. (%) of patients with microbiology cultures positive upon final debridement	20 (74)	7 (26)	2.5 (0.4–13.6)	0.3
Median no. of days of parenteral vancomycin treatment (IQR)	12 (9–17)	14 (7–23)	1.0 (0.9–1.1)	0.2
No. (%) of patients with duration of antibiotic therapy (oral and parenteral)
>365 days	18 (90)	2 (10)	1 (ref)
180–365 days	13 (87)	2 (13)	1.4 (0.2–11.1)	0.8
90–180 days	2 (67)	1 (33)	4.5 (0.3–74.7)	0.3
<90 days	1 (20)	4 (80)	36 (2.6–501.3)	0.008

^aOR, odds ratio; ref, reference. Boldface type indicates significant value (P < 0.05).