Predictive Value Of Neutrophil-to-lympbocyte Ratio In Aged Patients With Communiyt-Acquired Pneumonia

Objective:Community-acquired pneumonia (CAP) is a common cause of emergency treatment and hospitalization among the elderly,To investigate the predictive value of neurtophils-to-lymphocytes ratio(NLR) in the aged patients with community acquired pneumonia.Methods:A retrospective cohort study was conducted from January2010to June2012in Xiamen174Hospital, Anhui Medical University.297elderly patients with CAP were admitted to the respiratory ward or intensive care unit(ICU). Using the Hospital Information System and Medical Record Management System database, clinical data were retrospectively compared. According to CURB-65scores, all patients were divided into low risk group (n=193) and high risk group (n=104) respectively. And according to etiology after admission training results into germiculture positive groups (n=157) and germiculture negative group (n=140).Collecting the basic situation (with age, sex, combined basic diseases), clinical symptoms, signs, imageological examination(X-ray chest radiograph and lung CT), laboratory examination(the white blood cell (WBC), neutrophil-to-lymphocyte ratio(NLR), procalcitonin(PCT), hepatic and renal function were measuered on day1after admission), Phlegm and blood bacteria culture, clinical outcome(death) and hospitalizations days.Data between the two groups was compared, the relationship between NLR and CURB-65scores was analysised, and statistical analysis was carried out on the elderly CAP death predictive value. Results:Results:In this study,297elderly patients with CAP were collected, including174males and123females with an average age of (76.42±6.83) years(range,65-93years) and an average hospitalization days of (10.17±5.27)days (range,1-38days).There were30cases of death,1in the low-risk group,29in the high-risk group.80cases received PCT test and the average value was2.61±1.59ug/L.The levels of NLR in high risk group (6.39±4.23) were higher significantly than that in the low risk group (2.85±1.06)(P<0.01). The levels of WBC between the high risk group and low risk group were no significantly difference (P>0.05). Sputum or blood culture results:140cases of bacterial negative,Positive pathogens in157cases, with126cases positive bacteria, fungi,31cases. Gram-negative bacteria was cultured accounts for81cases (51.67%), gram positive bacteria,45cases (28.63%). The levels of NLR in germiculture positive group(5.62±3.22) were higher singificantly than that in the germiculture negative group (2.95±2.77), the comparative difference was statistically significant (P<0.01).The results of correlation analysis between the NLR and each index were as follows:the correlation coefficient between the NLR and the WBC was r=0.102, p>0.05; between the NLR and the PCT was r=0.890, p<0.01; between the NLR and CURB-65was r=0.608, p<0.01; between the NLR and hospitalization days was r=0.333,p<0.01. The correlation between NLR and WBC was not strong, but with the CURB-65and the PCT were strong, and the NLR and hospitalization days had positive correlation. In these four indicators,the NLR, PCT, CURB-65were statistically significant predictive index for death according the area under ROC curve,but the prediction effect of the WBC count was not obvious.Through the ROC analysis,we found that the NLR=5.655was an effective predictive index of death for elderly CAP patients,with the sensitivity of60%, specificity of82%and the area under the curve (AUC)of0.781.Conclusion Neutrophil/lymphocyte ratio can be used for clinical assessment of disease severity in elderly patients with CAP, and also have some significance for forecasting death of the elderly patients with CAP.