The Prognostic Role of Pitt Bacteremia Score in Patients With Nonbacteremic <i>Klebsiella pneumoniae</i> Infections

<b>Background:</b> <i>Klebsiella pneumoniae</i> infection causes various diseases and leads to significant morbidity and mortality. The Pitt bacteremia score (PBS) is a well-known prognostic predictor in patients with bacteremia. We aimed to investigate the prognostic role of the PBS in patients with nonbacteremic <i>K. pneumoniae</i> infections and compare its mortality discriminative ability with that of other risk scoring systems. <b>Methods:</b> Data were retrospectively collected from emergency department patients in E-Da Hospital, Kaohsiung, Taiwan, within 2021. All adult patients (aged ≥ 20 years) during this period and diagnosed with <i>K. pneumoniae</i> infections were included. The baseline demographics, laboratory results, infection sources, and clinical outcomes of nonbacteremic patients were extracted, and the patients were further divided into low (< 4) and high (≥ 4) PBS groups for comparison. <b>Results:</b> A total of 863 patients with <i>K. pneumoniae</i> infection were identified, and 639 nonbacteremic patients were enrolled. There were similar demographics between the bacteremic and nonbacteremic groups. Regarding clinical outcomes in nonbacteremic patients, the high PBS group had significantly higher risk of septic shock (77.9% vs. 4.8%, <i>p</i> < 0.01), intensive care unit admission (71.3% vs. 8.2%, <i>p</i> < 0.01), respiratory failure (71.3% vs. 2.4%, <i>p</i> < 0.01), and 30-day mortality (34.6% vs. 3.8%, <i>p</i> < 0.01). The area under the curve of the scoring systems regarding 30-day mortality prediction ability was as follows: sequential organ failure assessment score 0.89 (95% confidence interval [CI] = 0.86-0.91), PBS 0.86 (95% CI = 0.83-0.88), quick sequential organ failure assessment score 0.71 (95% CI = 0.67-0.74), and systemic inflammatory response syndrome 0.62 (95% CI = 0.58-0.66). <b>Conclusion:</b> PBS correlated with adverse outcomes and good mortality prediction ability in patients with nonbacteremic <i>K. pneumoniae</i> infections.