Neutrophil-to-lymphocyte Ratio as a Prognostic Indicator in Patients with Nursing and Healthcare-associated...

Objective Nursing and healthcare-associated pneumonia (NHCAP) is common in Japan's aging society and is frequently recurrent, highlighting the need for reliable prognostic markers. The neutrophil-to-lymphocyte ratio (NLR) has been associated with the prognosis in various diseases. This study was performed to evaluate the prognostic value of the NLR in NHCAP. Methods We retrospectively collected data from patients treated under a clinical pathway for NHCAP at Hamamatsu Medical Center between November 2019 and November 2023. Patients meeting the definition of NHCAP were categorized into NLR-high and NLR-low groups based on the cutoff value for the NLR using the Youden index for predicting 30-day mortality. The prognosis was compared using the Kaplan-Meier method, log-rank test, and Cox proportional hazards model. The primary outcome was the 30-day overall survival (OS), defined as mortality within 30 days after admission. Results A total of 158 eligible patients were stratified into NLR-high (n=78) and NLR-low (n=80) groups based on the cutoff value (10.1). The NLR-low group showed significantly better 30-day OS than the NLR-high group (p<0.001). After adjustment for the A-DROP (age, dehydration, respiratory failure, orientation disturbance and low blood pressure) score and body mass index, mortality risk remained elevated in the NLR-high group (hazard ratio, 6.8; 95% confidence interval, 2.0-23.1; p=0.002). Furthermore, incorporating the NLR into the A-DROP score (NA-DROP) further improved its discriminative ability for predicting 30-day mortality, showing an area under the curve of 0.751 (95% confidence interval, 0.648-0.853). Conclusion Elevated NLR was associated with worse 30-day outcomes in patients with NHCAP. Therefore, the NLR may be useful as a prognostic indicator in this population.