Urea-to-Albumin Ratio and In-Hospital Mortality in Severe Pneumonia Patients

Abstract

Objective. The urea-to-albumin ratio (UAR), as a new marker of the systemic inflammatory response, is associated with the mortality in pneumonia patients. However, the association between the UAR and in-hospital mortality in severe pneumonia (SP) has received little attention. Methods. In this single-center retrospective cohort study, 212 SP patients in intensive care unit (ICU) from June 1, 2016, to June 1st, 2020, with baseline UAR were enrolled. The primary outcome was in-hospital mortality. The association of UAR with in-hospital mortality was assessed using a multivariable-adjusted Cox model. Results. Of 212 patients, the median age was 73.0 (61.0, 82.8) years, 70.8% of patients were male, and the APACHE II score was 20.0 (16.0, 26.0). During the hospital period, 101 (47.6%) patients died. In-hospital mortality rates for the lower and higher UAR were 16 (27.6%) and 85 (55.2%), respectively <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mfenced open="(" close=")" separators="|"> <a:mrow> <a:mi>P</a:mi> <a:mo>&lt;</a:mo> <a:mn>0.001</a:mn> </a:mrow> </a:mfenced> </a:math> . Kaplan–Meier analysis revealed that survival rates were significantly different between the two groups (log rank = 13.71, <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" id="M2"> <f:mi>P</f:mi> <f:mo>&lt;</f:mo> <f:mn>0.001</f:mn> </f:math> ). After adjusted for confounding factors, the higher UAR group was significantly associated with a hazard ratio (HR) for in-hospital mortality of 2.234 (95% confidence interval: 1.146–4.356, <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" id="M3"> <h:mi>P</h:mi> <h:mo>=</h:mo> <h:mn>0.018</h:mn> </h:math> ). Besides, this pattern persisted in subgroup analyses considering sex (HR = 9.380; 95% CI: 2.248–39.138; <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" id="M4"> <j:mi>P</j:mi> <j:mo>=</j:mo> <j:mn>0.002</j:mn> </j:math> ). Conclusions. Higher UAR levels at the commencement of admission to ICU may be independently associated with increased in-hospital mortality in SP patients.