Chronic dialysis patients with infectious spondylodiscitis have poorer outcomes than non-dialysis populations

Figures & data

Figure 1 The flowchart of study patient enrollment.

Table 1 Demographics of chronic dialysis vs non-dialysis group

Patient characteristics	Chronic dialysis (N=105) (%)	Non-dialysis (N=197) (%)	p-value
Age (years), mean ± SD	66.7±10.8	63.2±9.4	0.977
Male gender	51 (48.6)	96 (48.7)	0.979
Diabetes mellitus	51 (48.6)	89 (45.2)	0.573
Hypertension	67 (63.8)	55 (27.9)	<0.001
Coronary artery disease	23 (21.9)	11 (5.6)	<0.001
Congestive heart failure	17 (16.2)	15 (7.6)	0.021
Cerebrovascular accident	12 (11.4)	14 (7.1)	0.202
Cirrhosis	10 (9.5)	20 (10.2)	0.862
Active malignancy	6 (5.7)	14 (7.1)	0.643
Immunosuppression	3 (2.9)	14 (7.1)	0.127
Degenerative spinal disease	89 (84.8)	186 (94.4)	0.005
Vertebral trauma	3 (2.9)	15 (7.6)	0.094

Table 2 Clinical characteristics of infectious spondylodiscitis in chronic dialysis vs non-dialysis group

Clinical features	Chronic dialysis (N=105) (%)	Non-dialysis (N=197) (%)	p-value
Disease manifestations
Fever	36 (34.3)	92 (46.7)	0.038
Back pain	80 (76.2)	164 (83.2)	0.138
Shock	24 (22.9)	33 (16.8)	0.197
Concurrent infective endocarditis	2 (1.9)	4 (2.0)	0.941
Possible primary focus
Spine surgery	9 (8.6)	26 (13.2)	<0.001
Soft tissue infection	5 (4.8)	13 (6.6)
Vascular access	32 (30.5)	0 (0)
Pneumonia	0 (0)	5 (2.5)
Urinary tract infection	2 (1.9)	17 (8.6)
Peritonitis	0 (0)	1 (0.5)
Unknown	57 (54.3)	135 (68.5)
Positive tissue culture	39 (37.1)	84 (42.6)	0.238
Positive blood culture	60 (57.1)	85 (43.1)	0.387
Laboratory data
Hemoglobin (g/dL)	9.4±1.6	10.7±2.1	<0.001
Albumin (g/dL)	3.0±0.5	2.9±0.7	0.384
Blood urea nitrogen (mg/dL)	48.7±23.6	26.3±21.9	<0.001
Creatinine (mg/dL)	6.2±2.3	1.3±1.2	<0.001
Alkaline phosphatase (U/L)	164.5±143.50	142.6±93.2	0.182
CRP (baseline) (mg/L)	123.7±91.5	122.9±113.9	0.951
CRP (1 week after treatment) (mg/L)	85.1±71.8	68.4±61.8	0.046
WBC (baseline) (1,000/μL)	11.8±5.8	11.8±6.6	0.997
WBC (1 week after treatment) (1,000/uL)	10.1±4.4	10.1±12.7	0.140
ESR (mm/hr)	86.6±33.6	70.0±31.7	0.001
Features of the involved vertebral lesions
Cervical spine	11 (10.5)	21 (10.7)	0.961
Thoracic spine	14 (13.3)	39 (19.8)	0.160
Lumbar spine	89 (84.8)	150 (76.1)	0.079
Sacral spine	10 (9.5)	27 (13.7)	0.291
Skipping lesions	5 (4.8)	5 (2.5)	0.304
Abscess formation	51 (48.6)	120 (60.9)	0.039
Invasive interventions
CT-guided drainage	14 (13.3)	19 (9.6)	0.328
Surgery	56 (53.3)	124 (62.9)	0.105

Abbreviations: CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; WBC, white blood cells.

Table 3 Microbiologic data of the chronic dialysis vs non-dialysis group

Microorganism species	Chronic dialysis (N=105) (%)	Non-dialysis (N=197) (%)	p-value
Gram-positive cocci	62 (59.1)	84 (42.6)	0.0064
Methicillin-susceptible Staphylococcus aureus	9 (8.6)	38 (19.2)
Methicillin-resistant S. aureus	30 (28.6)	22 (11.2)
Coagulase-negative staphylococci	14 (13.3)	8 (4.1)
Streptococcus spp.	2 (1.9)	12 (6.1)
Enterococcus	7 (6.6)	4 (2.0)
Gram-negative bacilli	1 (0.95)	29 (14.7)	0.0001
Escherichia coli	0 (0)	14 (7.1)
Klebsiella pneumoniae	1 (0.95)	8 (4.1)
Pseudomonas aeruginosa	0 (0)	4 (2.0)
Salmonella enterica	0 (0)	3 (1.5)
Fungus	1 (0.95)	4 (2.0)	0.4939
Candida parapsilosis	1 (0.95)	1 (0.5)
Candida glabrata	0 (0)	1 (0.5)
Candida albicans	0 (0)	1 (0.5)
Yeast-like	0 (0)	1 (0.5)
Mycobacterium	2 (1.9)	6 (3.1)	0.5395
Mycobacterium tuberculosis	1 (0.95)	4 (2.0)
Mycobacterium chelonae	1 (0.95)	1 (0.5)
Mycobacterium abscessus	0 (0)	1 (0.5)
Polymicrobial isolates	4 (3.8)	7 (3.6)	0.9300
Others	1 (0.95)	5 (2.5)
Unknown	34 (32.4)	62 (31.5)	0.8731

Figure 2 Kaplan–Meier survival curves of 1-year survival between chronic dialysis and non-dialysis patients with infectious spondylodiscitis.

Table 4 Outcomes of the chronic dialysis vs non-dialysis group

Outcomes	Chronic dialysis (N=105) (%)	Non-dialysis (N=197) (%)	p-value
Length of hospital stay (days), mean ± SD	62.78±39.30	51.65±30.43	0.012
In-hospital survival	86 (81.9)	179 (90.9)	0.024
1-year survival	80 (76.2)	176 (89.3)	0.002
1-year recurrence	17 (16.2)	39 (19.8)	0.722