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

Abstract

Background

The prognosis of ABA-HAP patients is very poor. This study aimed to develop a scoring model to predict ABA-HAP in patients with GNB-HAP.

Methods

A single center retrospective cohort study was performed among patients with HAP caused by GNB in our hospital during January 2019 to June 2019 (the derivation cohort, DC). The variables were assessed on the day when qualified respiratory specimens were obtained. A prediction score was formulated by using independent risk factors obtained from logistic regression analysis. It was prospectively validated with a subsequent cohort of GNB-HAP patients admitted to our hospital during July 2019 to Dec 2019 (the validation cohort, VC).

Results

The final logistic regression model of DC included the following variables: transferred from other hospitals (3 points); blood purification (3 points); risk for aspiration (4 points); immunocompromised (3 points); pulmonary interstitial fibrosis (3 points); pleural effusion (1 points); heart failure (3 points); encephalitis (5 points); increased monocyte count (2 points); and increased neutrophils count (2 points). The AUROC of the scoring model was 0.845 (95% CI, 0.796 ~ 0.895) in DC and 0.807 (95% CI, 0.759 ~ 0.856) in VC. The scoring model clearly differentiated the low-risk patients (the score < 8 points), moderate-risk patients (8 ≤ the score < 12 points) and high-risk patients (the score ≥ 12 points), both in DC (P < 0.001) and in VC (P < 0.001).

Conclusion

This simple scoring model could predict ABA-HAP with high predictive value and help clinicians to choose appropriate empirical antibiotic therapy.

Keywords:

• Acinetobacter baumannii
• hospital acquired pneumonia
• Gram-negative bacilli
• predictive scoring model
• empirical antibiotic therapy

Abbreviations

ABA, Acinetobacter baumannii; AUROC, the area under the receiver operating characteristic curve; DC, the derivation cohort; GNB, Gram-negative bacilli; GNB-HAP, hospital acquired pneumonia caused by Gram-negative bacilli; ICU, intensive care unit; LAMP, loop-mediated isothermal amplification; MDRAB, multidrug-resistant ABA; ROC, receiver operating characteristic; RT-PCR, real-time PCR; VC, the validation cohort; WGS, whole genome sequencing.

Data Sharing Statement

The datasets generated and analyzed during the present study are available from the corresponding author on reasonable request.

Ethics Approval

This study was approved by the Institutional Review Board of Tang Du Hospital, Fourth Military Medical University of the Chinese People’s Liberation Army (No. TDLL-KY-202101-07). This study complies with the Declaration of Helsinki.

Acknowledgments

Dr Guangyu Li has moved to Genotix Biotechnology, Inc. before the article has been published. And the current affiliation is Genotix Biotechnology, Inc. Sunnyvale, CA 94085, United States. E-mail: [email protected]. We would like to thank professor Lei Shang for providing statistical expertise with data analysis.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that there are no conflicts of interest in this work.

Additional information

Funding

There is no funding to report.