Study On The Clinical Value Of CURB-age Score Combined With CRP/PA On Community-acquired Pneumonia In The Elderly

Background and ObjectiveCommunity-acquired pneumonia（CAP）is a common clinical infectious disease that seriously affects the daily life of patients and leads to a decline in the quality of life.The elderly are high-risk groups of CAP,and the rapid progress of the disease can easily lead to a poor prognosis.Therefore,finding suitable indicators to evaluate the patient’s condition and predict the prognosis is of great significance for guiding clinical treatment.At present,domestic and foreign CAP diagnosis and treatment guidelines often use the CURB-65 score to assess the severity of pneumonia patients.Myint et al.proposed an improved CURB-65 score for elderly CAP and named it CURB-age,which mainly modified age and blood urea nitrogen to improve the specificity of disease diagnosis.At present,there are few relevant studies on this score at home and abroad.In recent years,more and more biomarkers have been recommended for evaluating the condition of CAP patients.A number of studies have reported that monitoring the level of C-reactive protein（CRP）after admission can determine the severity of the disease and the risk of death.Prealbumin（PA）is an acute reactive protein that appears within a short time after the stressor acts on the body.It decreases when invaded by foreign pathogens.PA can also reflect the body’s short-term nutritional status.As a new predictor,CRP/PA may have a higher evaluation value in predicting the prognosis of the disease.In the past,it was mostly used for research on malignant tumors,sepsis,pancreatitis,acute myocardial infarction,etc.,but research on CAP in the elderly is rare.This study aims to explore the clinical application value of CURB-age score combined with CRP/PA in elderly patients with CAP.Materials and MethodsWe retrospectively analysed the clinical data of 142 elderly CAP patients who were hospitalized in the Department of Respiratory Medicine and Intensive Care Unit（ICU）of the Second Affiliated Hospital of Zhengzhou University from January 2016to August 2020.We collected the patient’s general clinical data（sex,age,comorbidities）,the worst values of clinical signs and laboratory results within 24hours of admission:consciousness,respiratory rate,blood pressure,blood urea nitrogen（BUN）,CRP,PA,procalcitonin（PCT）,red blood cell distribution width（RDW）,white blood cell count（WBC）,platelet count（PLT）and D-dimer level.According to the 30-day clinical outcome of CAP,we divided the patients into survival group and death group,and compared the difference of two groups with CURB-65 score,CURB-age score,CRP,PA,CRP/PA,PCT,RDW,WBC,PLT and D-dimer level.Multivariate Logistic regression method was used to analyze independent risk factors that affect the short-term prognosis of elderly CAP patients.We built combined models by including inflammatory factors and CURB-age score and calculated the area under the ROC curve（AUC）for predicting the 30-day prognosis of elderly CAP patients.ResultsAccording to the 30-day clinical outcome of elderly CAP patients,we divided them into survival group and death group.There were 120 patients in the survival group,including 69 males and 51 females,with an average age of（77.09±7.53）years old,with comorbidities:56 cases of hypertension,45 cases of coronary heart disease,31 cases of diabetes,and 27 cases of chronic obstructive pulmonary disease.There were 22 patients in the death group,including 11 males and 11 females,with an average age of（79.23±7.48）years old,with comorbidities:14 cases of hypertension,11 cases of coronary heart disease,9 cases of diabetes,and 2 cases of chronic obstructive pulmonary disease.There were no statistically significant differences in gender（χ²=0.425）,age（t=1.225）and comorbidities(χ²_hypertension=2.142,χ²diabetes=2.088,χ²coronary heart disease=1.216,χ²chronic obstructive pulmonary disease=1.315)between the two groups（P>0.05）.The CURB-65 score,CURB-age score,CRP,CRP/PA,PCT,WBC and D-dimer levels of the death group were higher than those of the survival group（Z=-6.294,P=0.000;Z=-6.080,P=0.000;Z=-4.029,P=0.000;Z=-4.860,P=0.000;Z=-4.341,P=0.000;Z=-2.419,P=0.016;Z=-3.045,P=0.002）.The PA of the death group was lower than that of the survival group（t=-3.623,P=0.000）.There were no significant differences in RDW and PLT levels between the two groups（Z=-1.374,P=0.169;Z=-1.844,P=0.065）.Multivariate logistic regression analysis showed that CURB-age score was an independent risk factor for death in elderly CAP patients within 30 days（P<0.05）.The AUC of CURB-age score predicting death outcome was 0.892（P<0.05）.CRP/PA can significantly increase the prediction accuracy of CURB-age score for the short-term prognosis of elderly CAP patients（AUC=0.934,P<0.05）,and the difference was statistically significant（P^#<0.05）.CRP,PA,PCT,WBC and D-dimer increased the prediction effect of CURB-age score to different degrees（AUC was 0.917,0.920,0.908,0.905,0.909,respectively;P<0.05）,but there was no statistical significance（P^#>0.05）.Conclusions1.CURB-65 score,CURB-age score,CRP,PA,CRP/PA,PCT,WBC and D-dimer levels were all correlated with the prognosis of elderly patients with CAP,while RDW and PLT levels were not significantly correlated with the prognosis of elderly patients with CAP.2.CURB-age score was an independent risk factor affecting the prognosis of elderly CAP patients.3.Adding CRP/PA to the CURB-age score at admission can significantly improve the prediction accuracy of the 30-day prognosis of elderly CAP patients.