Derivation and Validation of a Predictive Scoring Model of Infections Due to Acinetobacter baumannii in Patients with Hospital Acquired Pneumonia by Gram-Negative Bacilli

Figures & data

Table 1 Patient Characteristics and Univariate Analysis Between ABA-HAP and Non-ABA-HAP Group

Clinical Variables	ABA-HAP Group (n=81)	Non-ABA-HAP Group (n=314)	P value (or Adjusted P value)
Age			0.088
≥ 18 years old	10	42
≥ 45 years old	32	159
> 65 years old	39	113
Gender (male)	56	234	0.328
Seasonal distribution (from November to April)	26	102	0.947
Smoking history			0.747
None	45	155
< 30 pack-years	7	70
≥ 30 pack-years	23	66
≥ 60 pack-years	6	23
Drinking history			0.569
None	71	245
Occasional	4	30
Often	6	39
Transferred from other hospitals	36	47	0.000
Days from the specimens collection date to the date admitted to hospital			0.040
< 7 days	27	149
≥ 7 days	32	96
≥ 14 days	22	69
Days from the specimens collection date to admission to ICU			0.000
Not stay in the ICU	16	131
< 7 days	24	102
≥ 7 days	32	58
≥ 14 days	9	23
Days from the specimens collection date to endotracheal intubation			0.000
No	16	121
≥ 1 days	31	123
≥ 7 days	23	48
≥ 14 days	11	22
Days from the specimens collection date to invasive ventilation			0.001
No	23	134
≥ 1 days	32	133
≥ 7 days	20	36
≥ 14 days	6	11
Days from the specimens collection date to general anesthesia surgery			0.513
No	52	173
≥ 1 days	6	77
≥ 7 days	17	41
≥ 14 days	6	23
General anesthesia surgery	29	141	0.084
Thoracic surgery	8	36	0.630
Brain surgery (including local anesthesia)	21	95	0.446
Hospitalization within the last 6 months	28	108	0.873
ICU admission within the last 3 months	8	9	0.010
Gastric tube intubation	68	207	0.002
Indwelling urinary catheter	71	208	0.000
Deep vein catheterization	41	110	0.010
Blood purification	9	10	0.007
Thoracic drainage	18	59	0.487
Gastroscopy	4	9	0.314
Bronchoscopy	60	166	0.001
Cranial drainage	13	86	0.036
Lumbar puncture	9	27	0.484
Bone marrow puncture	0	11	0.184
A history of cardiopulmonary resuscitation	3	2	0.061
Risk for aspiration	71	181	0.000
Immunocompromised	56	129	0.000
Shock	17	60	0.703
Respiratory failure	45	121	0.006
Dosage of budesonide inhalation (× 4 mL)			0.043
No	39	189
≥ 1×4 mL	18	56
≥ 7×4 mL	11	38
≥ 14×4 mL	13	31
Diabetes	12	40	0.622
COPD	20	64	0.398
Pulmonary bulla	9	28	0.542
Bronchiectasis	2	14	0.622
Pulmonary tuberculosis	1	9	0.662
Lung cancer	7	38	0.382
Coronary heart disease	15	36	0.091
Atrial fibrillation	10	19	0.053
Esophagus cancer	5	26	0.529
Intracranial tumour	2	16	0.477
Cerebral infarction	9	49	0.308
Cerebral hemorrhage	23	90	0.962
Craniocerebral trauma	6	42	0.143
Pulmonary interstitial fibrosis	11	20	0.031
Pleural effusion	34	68	0.000
Heart failure	14	13	0.000
Pericardial effusion	9	17	0.065
Hematological malignancy	0	17	0.029
Encephalitis	5	2	0.005
Hypertension			0.051
None	45	210
Grade 1 ~ 2	8	27
Grade 3	28	77
Prostate hyperplasia	4	22	0.503
Peritonitis	3	2	0.100
Hepatitis B	2	11	0.908
Myasthenia gravis	2	3	0.597
Renal cyst	7	23	0.690
Fractures of the pelvis or femur	3	9	0.977
Postsplenectomy	2	7	1.000
Hepatic cyst	13	24	0.021
Dosage of antacid (40 mg of omeprazole or other equivalent antacid)			0.058
None	17	85
≥ 1×40 mg	42	171
≥ 14×40 mg	18	32
≥ 28×40 mg	4	19
Leukocyte count			0.008
< 4 × 10^9/L	0	25
Normal	27	123
> 10 × 10^9/L	54	164
Decreased lymphocyte count	32	82	0.018
Increased monocyte count	69	216	0.003
Increased neutrophils count	62	176	0.001
Increased platelet count	13	38	0.345
Hemoglobin count (g/L)			0.647
Normal	30	126
≥ 90 g/L	31	114
≥ 60 g/L	19	71
< 60 g/L	1	3
Plasma albumin (g/L)			0.042
Normal	24	137
≥ 30 g/L	34	96
≥ 25 g/L	18	66
< 25 g/L	5	10
Plasma globulin			0.284
Decreased	14	41
Normal	54	207
Increased	13	61
Increased blood urea nitrogen	34	89	0.023
Procalcitonin			0.212
Normal	41	143
Increased	26	63
C-reaction protein			0.902
Normal	7	18
Increased	44	120
Fibrinogen degradation products (FDP)			0.000
Increased	72	194
Normal	7	79
D-dimer (mg/L)			0.008
Normal	4	34
≤ 10 mg/L	53	196
≤ 20 mg/L	17	22
> 20 mg/L	5	21

Table 2 Independent Risk Factors for Predicting ABA-HAP

Independent Risk Factors	Adjusted Odds Ratio (95% CI)	p value	Scoring Point
Transferred from other hospitals	3.988 (1.984, 8.014)	0.000	3
Blood purification	4.655 (1.212, 17.87)	0.025	3
Risk for aspiration	5.487 (2.284, 13.179)	0.000	4
Immunocompromised	4.335 (2.275, 8.258)	0.000	3
Pulmonary interstitial fibrosis	3.6 (1.249, 10.377)	0.018	3
Pleural effusion	1.929 (1.010, 3.682)	0.046	1
Heart failure	3.952 (1.356, 11.521)	0.012	3
Encephalitis	10.253 (1.473, 71.37)	0.019	5
Increased monocyte count	3.147 (1.381, 7.175)	0.006	2
Increased neutrophils count	2.140 (1.073, 4.27)	0.031	2

Table 3 The Diagnostic Efficiency of the Predictive Scoring Model at Different Cutoff Values

Cutoff Values	Sensitivity	Specificity	Youden Index	Accuracy Rate	Positive Likelihood Ratio	Negative Likelihood Ratio
1	100.00%	2.90%	0.029	22.81%	1.0299	0.0000
2	100.00%	3.20%	0.032	23.05%	1.0331	0.0000
3	100.00%	5.70%	0.057	25.04%	1.0604	0.0000
4	100.00%	11.50%	0.115	29.65%	1.1299	0.0000
5	100.00%	18.20%	0.182	34.97%	1.2225	0.0000
6	97.50%	23.90%	0.214	38.99%	1.2812	0.1046
7	93.80%	35.00%	0.288	47.06%	1.4431	0.1771
8	91.40%	44.60%	0.36	54.20%	1.6498	0.1928
9	82.70%	69.10%	0.518	71.89%	2.6764	0.2504
10	77.80%	79.30%	0.571	78.99%	3.7585	0.2799
11	71.60%	82.80%	0.544	80.50%	4.1628	0.3430
12	55.60%	92.70%	0.483	85.09%	7.6164	0.4790
13	39.50%	96.50%	0.36	84.81%	11.2857	0.6269
14	35.80%	97.10%	0.329	84.53%	12.3448	0.6612
15	27.20%	98.70%	0.259	84.04%	20.9231	0.7376
16	16.00%	99.70%	0.157	82.54%	53.3333	0.8425
17	13.60%	99.70%	0.133	82.04%	45.3333	0.8666
18	6.20%	99.70%	0.059	80.53%	20.6667	0.9408
19	3.70%	100.00%	0.037	80.25%		0.9630
20	1.20%	100.00%	0.012	79.74%		0.9880
21	0.00%	100.00%	0	79.49%		1.0000

Figure 1 The performance of the predictive scoring model in the derivation cohort. (A) ROC curve of the derivation cohort; (B) scores distribution of the different risk groups in the derivation cohort.

Figure 2 The incidence of ABA-HAP in the low-risk, moderate-risk and high-risk groups.

Figure 3 The performance of the predictive scoring model in the validation cohort. (A) ROC curve of the validation cohort; (B) scores distribution of the different risk groups in the validation cohort.