Microbiological characteristics and risk factors for multidrug-resistant organism infections in diabetic foot ulcer

Diabetic foot ulcer (DFU) is one of the most common complications of diabetes, and causes significant morbidity, mortality and healthcare expenditure. Multidrug-resistant organism (MDRO) infection is considered a major threat to the treatment of DFUs. This study investigated the risk factors for MDRO infections in DFUs.

This was a retrospective case-control study. Patients diagnosed with DFU and MDRO infections were included in the observation group. The same number of patients hospitalised during the same period and who were diagnosed with DFU but without MDRO infection were matched and selected as the control group. Binary logistic regression analysis was performed to evaluate the risk factors for multidrug-resistant organism (MDRO) infections in DFUs by analysing the clinical data. The receiver operating characteristic (ROC) curve was used for evaluation.

The electronic medical records of 110 patients (55 in each group, with similar sex and age) were reviewed. The results of binary logistic regression analysis showed that: history of antibiotic exposure (odds ratio (OR)=11.878; 95% confidence interval (CI): 3.064, 46.046; p<0.001); history of hospitalisation within one year (OR=3.198; 95% CI: 1.156, 8.846; p=0.025); hypertension (OR=3.976; 95% CI: 1.444, 10.951; p=0.008); and osteomyelitis (OR=21.667; 95% CI: 3.427, 137.002; p=0.001) were significant risk factors for MDRO infection in patients with a DFU. The logistic regression model for MDRO infection in patients with a DFU was fitted as follows: Logit (P) = (-3.482) + (2.475) × history of antibiotic exposure + (1.163) × history of hospitalisation within 1 year + (1.380) × hypertension + (3.076) × osteomyelitis. The ROC curve evaluation model was plotted. The area under the curve was 0.861 (95% CI: 0.794, 0.927; p<0.001).

The findings of this study showed that history of antibiotic exposure, history of hospitalisation within one year, hypertension, and osteomyelitis in combination were the risk factors for MDRO infections in patients with DFUs.