Pnömonide mortaliteyi öngörmede üre/kreatinin oranının değeri: propensity skor eşleştirmeli retrospektif bir çalışma

Year 2026, Volume: 8 Issue: 1, 91 - 96, 06.01.2026

İlker Şirin , Tuğba Sanalp Menekşe , Sedanur Şafak , Nur Vahapoğlu Vural , Gülşah Çıkrıkçı Işık

https://doi.org/10.38053/acmj.1829295

Abstract

Amaç: Bu çalışma, pnömoni tanısı alan hastalarda üre/kreatinin oranının (UCR) hastane içi mortaliteyi öngörmedeki prognostik değerini değerlendirmeyi ve karıştırıcı faktörleri en aza indirmek için yapılan propensity skor eşleştirmesi sonrasında nötrofil/lenfosit oranı (NLR) ile karşılaştırmayı amaçladı.
Yöntemler: Bu retrospektif, tek merkezli gözlemsel çalışmaya 2023–2025 yılları arasında acil servise başvuran, klinik ve radyolojik olarak pnömoni tanısı doğrulanmış yetişkin hastalar dahil edildi. Demografik özellikler, laboratuvar parametreleri ve klinik sonuçlar hastanenin elektronik tıbbi kayıt sisteminden elde edildi. UCR ve NLR, başvuru anındaki laboratuvar değerleri kullanılarak hesaplandı. Alıcı işletim karakteristiği (ROC) eğrisi analizleri, yaş, troponin I ve pro-BNP değerleri kullanılarak yapılan 1:1 en yakın komşu propensity skor eşleştirmesi öncesi ve sonrasında gerçekleştirildi. Birincil sonuç tüm nedenlere bağlı hastane içi mortaliteydi.
Bulgular: Toplam 2.884 hasta çalışmaya dahil edildi. Hayatta kalamayanlar (n=442), hayatta kalanlara (n=2.442; p<0.001) kıyasla anlamlı derecede daha yüksek UCR ve NLR seviyelerine sahipti. Genel kohortta UCR, mortaliteyi öngörmede güçlü bir performans sergiledi (Eğri altındaki alan (AUC) 0.76; %95 GA: 0.735–0.785) ve NLR’den (AUC 0.62; %95 GA: 0.591–0.648) daha üstün bulundu. Propensity skor eşleştirmesi sonrası (n = 826) UCR ayırt edici performansını korudu (AUC 0.729; %95 GA: 0.695–0.763) ve yine NLR’den (AUC 0.60) daha iyi performans gösterdi. UCR’nin duyarlılık, özgüllük, pozitif ve negatif prediktif değerleri hem eşleştirilmemiş hem de eşleştirilmiş analizlerde klinik olarak anlamlı ve tutarlı kaldı.
Sonuç: UCR, pnömoni hastalarında hastane içi mortaliteyi öngörmede orta düzeyde ancak klinik açıdan anlamlı bir yetenek göstermiş ve hem karıştırıcı faktörler ayarlanmadan önce hem de sonra NLR’den üstün bulunmuştur. Bu bulgular, UCR’nin pnömonide erken risk sınıflandırması için yararlı bir yardımcı biyobelirteç olarak hizmet edebileceğini düşündürmektedir.

Keywords

Pnömoni , Üre/Kreatinin Oranı , Nötrofil/Lenfosit Oranı , Mortalite , Biyobelirteçler , Propensity Skor Eşleştirmesi

Ethical Statement

Yerel etik komite bu çalışmayı onayladı. Karar no: AEŞH-BADEK1-2025-281; tarih: 6 Ağustos 2025.

Supporting Institution

Yok

Thanks

Yok

Value of the urea-to-creatinine ratio for predicting mortality in pneumonia: a retrospective study with propensity score matching

Abstract

Aims: This study aimed to evaluate the prognostic value of the urea-to-creatinine ratio (UCR) in predicting in-hospital mortality among patients diagnosed with pneumonia and to compare its performance with the neutrophil-to-lymphocyte ratio (NLR), while minimizing confounding factors by propensity score matching.
Methods: This retrospective, single-center observational study included adult patients with clinically and radiologically confirmed pneumonia who presented to the emergency department between 2023 and 2025. Demographic characteristics, laboratory parameters, and clinical outcomes were obtained from the hospital’s electronic medical record system. UCR and NLR were calculated using laboratory values recorded at admission. Receiver operating characteristic (ROC) curve analyses were performed both before and after 1:1 nearest-neighbor propensity score matching, which was conducted using age, troponin I, and pro-BNP as matching variables. The primary outcome was all-cause in-hospital mortality.
Results: A total of 2,884 patients met the inclusion criteria. Non-survivors (n=442) showed significantly higher UCR and NLR levels compared with survivors (n=2,442; p<0.001). In the overall cohort, UCR demonstrated strong predictive performance for mortality (Area under the curve (AUC) 0.76; 95% CI: 0.735–0.785), outperforming NLR (AUC 0.62; 95% CI: 0.591–0.648). After propensity score matching (n=826), UCR maintained its discriminatory performance (AUC 0.729; 95% CI: 0.695–0.763), again outperforming NLR (AUC 0.60). The sensitivity, specificity, positive predictive value, and negative predictive value of UCR remained clinically meaningful and consistent across both the unmatched and matched analyses.
Conclusion: UCR showed a moderate yet clinically relevant ability to predict in-hospital mortality among pneumonia patients and consistently outperformed NLR, both before and after adjustment for confounders. These findings suggest that UCR may serve as a useful adjunct biomarker for early risk stratification in pneumonia.

Keywords

Pneumonia , urea-to-creatinine ratio , neutrophil-to-lymphocyte ratio , mortality , biomarkers , propensity score matching

Ethical Statement

The local ethic committee approved this study. Decision no: AEŞH-BADEK1-2025-281; date: August 6, 2025.

Supporting Institution

None

Thanks

None

References

• Souza JS, Giglio BM, Lobo PCB, Araújo VA, Pimentel GD. Weak association between urea-creatinine ratio and C-reactive protein with nutritional risk in hospitalized patients with COVID-19: a cross-sectional study. Clin Nutr ESPEN. 2024;63:676-680. doi:10.1016/j.clnesp.2024.07.1053
• Sharma Y, Thompson C, Zinellu A, Shahi R, Horwood C, Mangoni AA. The role of the neutrophil-to-lymphocyte ratio in predicting outcomes among patients with community-acquired pneumonia. Clin Med (Lond). 2025;25(1):100278. doi:10.1016/j.clinme.2024.100278
• Hu Q, Pan P, Xiang B. The prognostic value of neutrophil-to-lymphocyte ratio combined with multiple indicators in patients with severe pneumonia. Signa Vitae. 2024;20(10). doi:10.22514/sv.2024.122
• Chen D, Yuan H, Cao C, et al. Impact of acute kidney injury on in-hospital outcomes in Chinese patients with community acquired pneumonia. BMC Pulm Med. 2021;21(1):143. doi:10.1186/s128 90-021-01511-9
• Shang N, Li Q, Ji W, Liu H, Guo S. Acute muscle wasting is associated with poor prognosis in older adults with severe community-acquired pneumonia. Eur Geriatr Med. 2024;15(1):73-82. doi:10.1007/s41999-02 3-00895-7
• Ryu S, Oh SK, Cho SU, et al. Utility of the blood urea nitrogen to serum albumin ratio as a prognostic factor of mortality in aspiration pneumonia patients. Am J Emerg Med. 2021;43:175-179. doi:10.1016/j.aj em.2020.02.045
• Overview | Pneumonia: diagnosis and management | Guidance | NICE. September 2, 2025. Accessed November 20, 2025.
• Austin PC. An introduction to propensity score methods for reducing the effects of confounding in observational studies. Multivariate Behav Res. 2011;46(3):399-424. doi:10.1080/00273171.2011.568786
• Efros O, Soffer S, Leibowitz A, et al. Risk factors and mortality in patients with pneumonia and elevated troponin levels. Sci Rep. 2020;10(1):21619. doi:10.1038/s41598-020-78287-1
• Lin SC, Tsai YJ, Huang CT, et al. Prognostic value of plasma N-terminal pro B-type natriuretic peptide levels in pneumonia patients requiring intensive care unit admission. Respirology. 2013;18(6):933-941. doi:10. 1111/resp.12096
• Paulus MC, Melchers M, van Es A, Kouw IWK, van Zanten ARH. The urea-to-creatinine ratio as an emerging biomarker in critical care: a scoping review and meta-analysis. Critical Care. 2025;29(1):175. doi:10. 1186/s13054-025-05396-6
• Chapple LAS, Kouw IWK, Summers MJ, et al. Muscle protein synthesis after protein administration in critical illness. Am J Respir Crit Care Med. 2022;206(6):740-749. doi:10.1164/rccm.202112-2780OC
• Boelens YFN, Melchers M, van Zanten ARH. Poor physical recovery after critical illness: incidence, features, risk factors, pathophysiology, and evidence-based therapies. Curr Opin Crit Care. 2022;28(4):409-416. doi:10.1097/MCC.0000000000000955
• Liu Q, Wang Y, Zhao X, et al. Diagnostic performance of a blood urea nitrogen to creatinine ratio-based nomogram for predicting in-hospital mortality in COVID-19 patients. Risk Manag Healthc Policy. 2021;14: 117-128. doi:10.2147/RMHP.S278365
• Alzoubi O, Khanfar A. Association between neutrophil to lymphocyte ratio and mortality among community acquired pneumonia patients: a meta-analysis. Monaldi Arch Chest Dis. 2021;92(3). doi:10.4081/monaldi.2021.2050
• Kaya AE, Ozkan S, Usul E, Arslan ED. Comparison of pneumonia severity scores for patients diagnosed with pneumonia in emergency department. Indian J Med Res. 2020;152(4):368-377. doi:10.4103/ijmr.IJ MR_595_18
• Zaki HA, Hamdi Alkahlout B, Shaban E, et al. The battle of the pneumonia predictors: a comprehensive meta-analysis comparing the Pneumonia Severity Index (PSI) and the CURB-65 score in predicting mortality and the need for ICU support. Cureus. 2023;15(7):e42672. doi: 10.7759/cureus.42672