RESUMEN
Objective To investigate the utility of combined detection of procalcitonin(PCT ) ,C‐reactive protein(CRP)and preal‐bumin(PA)in elderly patients with acute respiratory infectious diseases .Methods Detected the serum procalcitonin(PCT) ,C‐reac‐tive protein(CRP) and prealbumin(PA) of 110 elderly patients with acute respiratory infectious diseases and 40 healthy people dur‐ing the same period as control group .The levels of PCT and CRP and PA among groups were compared before and after treatment . The 110 elderly patients with acute respiratory infections were divided into into bacterial infection group(n= 40) ,virus infected group(n=34) and mixed infection group (n=36) according to the pathogen type .Results Before treatment ,the PCT and CRP of bacterial infection group and mixed infection group were significantly higher than that of control group ,while the level of PA was lower ,and the difference were statistically significant(P0 .05) .After treatment ,there was no significant difference .The sensitivity ,spe‐cificity ,accuracy ,positive predictive value ,negative predictive value ,and Youden′s index of combined detection of the three indica‐tors were higher than those of single detection in acute respiratory infection .Conclusion PCT ,CRP and PA can be used as the di‐agnostic indexes for elderly patients with acute respiratory tract infection .The combined detection of the 3 indexes can improve the accuracy of early diagnosis of acute respiratory tract infections in elderly patients and can be used in therapeutic efficiency evalua‐tion .