Risk factors for multidrug-resistant and extensively drug-resistant Acinetobacter baumannii infection of patients admitted in ICU: a systematic review and meta-analysis

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii infections pose challenges for clinical treatment and cause high mortality, particularly in intensive care units (ICUs). Identifying the risk factors for MDR and XDR infection is crucial, and existing findings remain controversial. We aim to systematically summarize and analyze the risk factors for MDR/XDR A. baumannii-infected patients admitted to ICUs. We searched PubMed, Embase, Web of Science, and the Cochrane Library for eligible original studies published in English before October 2023. We conducted meta-analysis where appropriate, with mean differences (MD) and odds ratios (ORs) calculated for continuous and nominal scaled data. The quality of the included studies was assessed using the Newcastle Ottawa scale (NOS). Ten studies reporting 1199 ICU patients (604 from general ICUs, 435 from neonatal ICUs, and 160 from pediatric ICUs) from eight countries were included in our analysis. The risk factors associated with MDR A. baumannii infection among patients admitted to general ICUs included a high APACHE Ⅱ score (MD = 7.52; 95% CI 3.24-11.80; P = 0.0006), invasive procedures (OR = 3.47; 95% CI 1.70-7.10; P = 0.0006), longer ICU stay (MD = 3.40; 95% CI: 2.94-3.86; P < 0.00001), and the use of antibiotics (OR = 2.69; 95% CI 1.22-5.94; P = 0.01). Moreover, in our sub-group analysis, longer neonatal ICU stay (MD = 16.88; 95% CI 9.79-23.97; P < 0.00001) was found to be associated with XDR A. baumannii infection. These findings indicate that close attention should be paid to patients with longer ICU stays, undergoing invasive procedures, using antibiotics, and with high APACHE Ⅱ scores to reduce the risk of MDR and XDR A. baumannii infections.