Clinical response and hospital costs associated with the empirical use of vancomycin and linezolid for hospital-acquired pneumonia in a Chinese tertiary care hospital: a retrospective cohort study

Figures & data

Figure 1 Flow chart to identify eligible hospitalized patients receiving empirical treatment with vancomycin or linezolid for hospital-acquired pneumonia.

Table 1 Summary of patient baseline characteristics associated with empirical use of vancomycin and linezolid for treating difficult hospital-acquired pneumonia

Treatment Sample size Variables	Vancomycin			Linezolid			P-value
	621			60
	N	Mean/%	SD	N	Mean/%	SD
Age (years)	621	56.4	12.7	60	60.2	17.3	0.035
Male	437	70.4		44	73.3		0.767
Basic medical insurance for urban residents	192	30.9		13	21.7		0.144
Out-of-pocket	422	68.0		43	71.7		0.664
Main comorbidities
Hypertension	161	25.9		12	20.0		0.355
Heart failure	145	23.4		6	10.0		0.015
Diabetes	36	5.8		3	5.0		1.000
Atrial fibrillation	36	5.8		1	1.7		0.240
Coronary heart disease	25	4.0		1	1.7		0.720
Hospital admission diagnosis
Coronary heart disease	146	23.5		8	13.3		0.077
Multiple valve diseases	124	20.0		2	3.3		0.001
Aortic aneurysm and dissection	86	13.9		11	18.3		0.335
Acute and subacute endocarditis	77	12.4		4	6.7		0.293
Lung or digestive system cancer	57	9.2		24	40.0		<0.001
Rheumatic mitral valve diseases	56	9.0		2	3.3		0.152
Non-rheumatic aortic valve disorders	44	7.1		2	3.3		0.417
Cardiomyopathy	13	2.1		2	3.3		0.634
Myocardial infarction	12	1.9		2	3.3		0.354
Bronchoalveolitis	6	1.0		3	5.0		0.037
Main intervention for hospital admission diagnosis
Heart surgery	524	84.4		22	36.7		<0.001
Liver surgery	18	2.9		7	11.7		0.004
Stomach surgery	16	2.6		10	16.7		<0.001
Symptom control	22	3.5		9	15.0		0.001
Breath status
Spontaneous breath	376	60.6		38	63.3		0.782
Mechanical ventilation	18	30.4		16	26.7		0.659
Tracheotomy	13	2.1		2	3.3		0.634
Type of ward
General ward	545	87.8		50	83.3		0.311
ICU	76	12.2		10	16.7		0.311
Image method for HAP diagnosis
Chest X-ray	521	83.9		49	81.7		0.715
CT	100	16.1		11	18.3		0.714
HAP-related information
Hospital stay length prior to HAP diagnosis (days)	621	10.2	14.6	60	15.6	9.3	0.005
Hospital stay length >48 hours prior to HAP diagnosis	596	96.0		56	93.3		0.312
Body temperature	131	37.2	0.8	20	37.2	1.0	0.903
White blood cell count	543	10.9	5.7	57	12.3	5.5	0.081
Previous use of mechanical ventilation	132	21.3		28	46.7		<0.001
Antibiotics resistance test	3	0.5		2	3.3		0.064
Positive antibiotics resistance test	3	0.5		2	3.3		0.064
Previous antibiotics treatment
Cephalosporins	272	43.8		14	23.3		0.002
Anti-pseudomonal β-lactams	5	0.8		4	6.7		0.005
Other β-lactams	267	43.0		30	50.0		0.340
Penicillins	27	4.4		3	5.0		0.741
Quinolones	36	5.8		7	11.7		0.090
Aminoglycosides	2	0.3		0	0.0		1.000
Macrolides	6	1.0		1	1.7		0.477
Treatment information
Treatment duration (days)	621	7.9	8.8	60	9.3	12.6	0.287
Treatment dosage (mg/day)	621	1,497.7	592.9	60	1,110.5	347.9
Concomitant antibiotic treatment
Cephalosporins	222	35.8		11	18.3		0.007
Anti-pseudomonal β-lactams	6	0.9		4	6.7		0.005
Other β-lactams	117	18.8		5	8.3		0.051
Quinolones	54	8.7		7	11.7		0.474
Penicillins	9	1.5		1	1.7		0.605
Macrolides	5	0.8		1	1.7		0.426
Aminoglycosides	1	0.2		0	0.0		1.000
Others	87	14.0		14	23.3		0.058

Abbreviations: CT, computed tomography; HAP, hospital-acquired pneumonia; ICU, intensive care unit; SD, standard deviation.

Figure 2 The changes in P-values associated with unbalanced patient baseline characteristics between the empirical use of vancomycin and linezolid after propensity score matching.

Note: The P-values in bold are significant.
Abbreviations: HAP, hospital-acquired pneumonia; vs, versus.

Figure 3 Risk differences in treatment failure at the end of treatment, pneumonia-related mortality and all-cause mortality at hospital discharge between vancomycin and linezolid after adjusting unbalanced patient baseline characteristics between the propensity score matched treatment groups. (A) Treatment failure at the end of treatment. (B) Pneumonia-related mortality at hospital discharge. (C) All-cause mortality at hospital discharge.

Note: The P-value in bold is significant.
Abbreviations: CI, confidence interval; HAP, hospital-acquired pneumonia; OR, odds ratio; vs, versus.

Table 2 Head-to-head comparisons on clinical outcomes between empirical use of vancomycin and linezolid for difficult hospital-acquired pneumonia in propensity score matched patients

Treatment Sample size Clinical outcomes	Vancomycin		Linezolid		P-value
	60		60
	n	%	n	%
At the end of treatment
Clinical cure	18	30.0	19	31.7	0.847
Clinical improvement	4	6.7	6	10.0	0.480
Treatment failure	33	55.0	27	45.0	0.289
Pneumonia-related complications
Respiratory failure	1	1.7	3	5.0	0.317
Infection shock	0	0.0	1	1.7	1.000
Pneumonia-related mortality	0	0.0	1	1.7	1.000
All-cause death	0	0.0	1	1.7	1.000
At hospital discharge
Pneumonia-related mortality	1	1.7	6	10.0	0.059
All-cause mortality	2	3.3	11	18.3	0.013

Note: The P-value in bold is significant.

Table 3 Head-to-head comparisons on the allocation of hospital costs associated with empirical use of vancomycin and linezolid for difficult hospital-acquired pneumonia in propensity score matched patients

Treatment Sample size Allocation of hospital costs	Vancomycin			Linezolid			Median difference	P-value
	60			60
	Mean	SD	Median	Mean	SD	Median
Drug acquisition for studied antibiotic	4,062	3,276	2,880	9,062	6,922	8,194	−5,314	<0.001
Other medications	96,888	141,202	55,594	90,807	80,412	69,061	−13,467	0.626
Medical examinations	4,594	5,420	3,059	5,460	4,926	3,807	−748	0.042
Medical supplies	24,862	19,375	20,598	31,940	27,604	25,532	−4,934	0.125
Other unclassified care	44,195	46,351	27,686	56,112	45,437	44,826	−17,141	0.006
Total hospital costs	174,601	196,307	113,160	193,380	141,979	133,825	−20,665	0.076

Note: Data in RMB (1 RMB =0.16 USD).

Abbreviation: SD, standard deviation.