Lower neutrophil-to-lymphocyte ratio predicts high risk of multidrug-resistant Pseudomonas aeruginosa infection in patients with hospital-acquired pneumonia

Figures & data

Figure 1 Flow diagram of study inclusion.

Figure 2 Receiver operating characteristic curve for neutrophil-to-lymphocyte ratio.

Abbreviation: AUC, area under curve.

Table 1 Comparison between MDR-PA and non-MDR-PA HAP

Characteristics	MDR-PA (N=69, 43.9%)	Non-MDR-PA (N=88, 56.1%)	OR	95% CI	P-value
Age, year	57.20±17.63	57.90±18.70	–	–	0.815
Sex/male	46 (66.7%)	66 (75.0%)	–	–	0.253
Duration of hospitalization before infection (day)	14.83±19.57	11.25±13.02	–	–	0.180
Prior endotracheal intubation	53 (76.8%)	52 (59.1%)	0.436	0.216–0.880	0.021
Prior mechanical ventilation	36 (52.2%)	32 (36.4%)	0.524	0.276–0.995	0.048
Prior ICU stay	42 (60.9%)	33 (37.5%)	0.386	0.202–0.737	0.004
IAT	53 (76.8%)	18 (20.5%)	0.078	0.036–0.166	0.000
Prior cephalosporin therapy	36 (52.2%)	40 (45.5%)	–	–	0.403
Admission >2 departments	59 (85.5%)	36 (40.9%)	0.117	0.053–0.259	0.000
WBC (×10^9 cells/L)	10.26±5.87	12.45±12.91	–	–	0.227
Neu (×10^9 cells/L)	7.91±5.03	8.75±4.42	–	–	0.126
LYM (×10^9 cells/L)	1.87±0.83	1.30±1.57	–	–	0.162
Mono (×10^9 cells/L)	0.73±0.73	0.68±0.47	–	–	0.082
NLR	7.06±5.72	10.21±8.32	0.933	0.885–0.985	0.012
HGB (g/L)	98.77±21.08	106.5±21.23	0.983	0.967–0.998	0.026
Effect of antibiotic treatment	19 (27.5%)	54 (61.4%)	4.180	2.116–8.254	0.000
30-day mortality	12 (17.3%)	2 (2.3%)	–	–	0.805

Notes: Data were presented by median (interquartile range), numbers (percentage), or mean ± standard deviation (x±s) (continuous data). Continuous variables were compared using Student’s t-test or Mann–Whitney U-test and categorical variables using Pearson’s chi-square or Fisher’s exact probability test. P-value <0.05 is considered significant.

Abbreviations: HAP, hospital-acquired pneumonia; HGB, hemoglobin; IAT, inappropriate antibiotic therapy; ICU, intensive care unit; LYM, lymphocyte; MDR-PA, multidrug resistant Pseudomonas aeruginosa; Mono, monocyte; Neu, neutrophil; NLR, neutrophil-to-lymphocyte count ratio; WBC, white blood cell.

Table 2 Multivariate analysis of risk factors associated with MDR-PA HAP

Characteristics	MDR-PA (N=69, 43.9%)	Non-MDR-PA (N=88, 56.1%)	OR	95% CI	P-value
Prior endotracheal intubation (day)	53 (76.8%)	52 (59.1%)	–	–	0.617
Prior mechanical ventilation (day)	36 (52.2%)	32 (36.4%)	–	–	0.900
Prior ICU stay (day)	42 (60.9%)	33 (37.5%)	–	–	0.806
IAT	53 (76.8%)	18 (20.5%)	0.103	0.044–0.244	0.000
Admission >2 departments	59 (85.5%)	36 (40.9%)	0.186	0.072–0.476	0.000
NLR	7.06±5.72	10.21±8.32	0.911	0.843–0.985	0.020
HGB (g/L)	98.77±21.08	106.5±21.23	–	–	0.164

Notes: Data were presented by median (interquartile range), numbers (percentage), or mean ± standard deviation (x±s) (continuous). Continuous variables were compared using Student’s t-test or Mann–Whitney U-test and categorical variables using Pearson’s chi-square or Fisher’s exact probability test. P-value <0.05 is considered significant.

Abbreviations: HAP, hospital-acquired pneumonia; HGB, hemoglobin; IAT, inappropriate antibiotic therapy; ICU, intensive care unit; MDR-PA, multidrug resistant Pseudomonas aeruginosa; NLR, neutrophil-to-lymphocyte count ratio.

Table 3 The prognosis associated with MDR-PA HAP

Characteristics	MDR-PA (N=69, 43.9%)	Non-MDR-PA (N=88, 56.1%)	OR	95% CI	P-value
Effect of antibiotic treatment	19 (27.5%)	54 (61.4%)	4.263	2.142–8.483	0.000
30-day mortality	2 (2.9%)	2 (2.3%)	–	–	0.653

Notes: Data were presented by numbers (percentage). Categorical variables were compared using Pearson’s chi-square or Fisher’s exact probability test. P-value <0.05 is considered significant.

Abbreviations: HAP, hospital-acquired pneumonia; MDR-PA, multidrug resistant Pseudomonas aeruginosa.

Figure 3 Kaplan–Meier survival curves according to MDR-PA infection.

Abbreviation: MDR-PA, multidrug resistant Pseudomonas aeruginosa.

Table 4 Comparison based on in vitro susceptibility tests

Characteristics	MDR-PA (N=42)	Non-MDR-PA (N=82)	OR	95% CI	P-value
Effect of antibiotic treatment	13 (31.0%)	51 (62.2%)	3.670	1.698–8.198	0.001
Aminoglycosides	14 (33.3%)	75 (91.5%)	–	–	<0.001
Carbapenems	29 (69.0%)	70 (85.3%)	–	–	0.032
Cephalosporins	26 (61.9%)	65 (79.3%)	–	–	0.038
Gyrase inhibitors	23 (54.8%)	68 (83.0%)	–	–	<0.001
Penicillin + β-lactamase inhibitors	33 (78.6%)	69 (84.1%)	–	–	0.442
Epoxide	13 (31.0%)	60 (73.2%)	–	–	<0.001
Polymyxin	42 (100%)	81 (98.8%)	–	–	>0.999
30-day mortality	2 (4.8%)	2 (2.4%)	–	–	0.488

Notes: Data were presented by numbers (percentage). Categorical variables were compared using Pearson’s chi-square or Fisher’s exact probability test. P-value <0.05 is considered significant.

Abbreviation: MDR-PA, multidrug resistant Pseudomonas aeruginosa.