Abstract:Objective To investigate the value of plasma D-dimer level in predicting 30-day mortality for the elderly patients with severe community-acquired pneumonia (CAP). Methods A total of 152 elderly inpatients (over 60 years old) with identified severe CAP admitted in our department from August 2009 to August 2011 were enrolled in this study. Immediately after admission, their blood samples were obtained for plasma levels of D-dimer and C-reactive protein (CRP), and pneumonia severity index (PSI) was calculated. Clinical and laboratory variables and 30-day mortality were recorded. Receiver operating characteristic (ROC) curve was used to assess the value of D-dimer for predicting 30-day mortality, and the area under curve (AUC) was calculated. Results The D-dimer levels were (961.55±186.49)μg/L in the patients with PSI score in class Ⅳ, and (1 122.53±197.98)μg/L for those with score in class Ⅴ, respectively, with significant difference between them (t=5.159, P<0.001). The levels were significantly higher in non-survivors than in survivors [(1 112.59±215.25) vs (920.46±126.89)μg/L, t=6.239, P<0.001]. Pearson correlation analysis indicated that D-dimer level was significantly correlated with PSI score (r=0.47, P<0.0001). ROC curve showed that the AUC for D-dimer predictive value was 0.79 (95% CI=0.72 to 0.85), having no significant difference with that of PSI score (0.85, 95% CI=0.78 to 0.91, P=0.095). Conclusion D-dimer level is of great value for predicting 30-day mortality in the elderly patients with severe CAP.