A Mortality Prediction Nomogram for Stenotrophomonas maltophilia Bloodstream Infection.

Background: The World Health Organization classifies Stenotrophomonas maltophilia (S. maltophilia) as one of the most overlooked and difficult-to-treat multidrug-resistant pathogens. It mainly causes pneumonia and bloodstream infections (BSIs). Therefore, the aim of this study was to investigate the risk factors for mortality in patients with S. maltophilia BSIs and to construct a predictive nomogram model.

Methods: Clinical data were collected from patients with S. maltophilia BSIs who were admitted to the First Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2023. Prognostic risk factors were identified using Cox regression and LASSO analysis. A nomogram was developed based on a multivariate analysis and validated using bootstrap resampling, receiver operating characteristic curve analysis, and calibration plots.

Results: The mortality rate was 20.0% among 85 patients with S. maltophilia BSIs. Multivariable analysis identified septic shock (hazard ratio [HR] = 7.859, 95% confidence interval (CI): 1.569-79.607; P = 0.009) and respiratory diseases (HR = 7.602, 95% CI: 2.269-39.202; P < 0.001) as independent risk factors for mortality. A predictive nomogram model incorporating these factors demonstrated excellent discrimination, with a C-index of 0.872 and high area under the curve values for 14-day (0.922) and 28-day (0.882) mortality. Calibration analysis showed precise agreement between predicted and observed outcomes.

Conclusion: Septic shock and respiratory diseases were independent risk factors for mortality in patients with S. maltophilia BSIs. The nomogram model developed in this study showed good predictive value for the survival rates of patients with S. maltophilia BSIs, thus facilitating clinical prevention and treatment.