ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the value of C-reactive protein (CRP) to diagnostic test in elderly patients with infections.</p><p><b>METHODS</b>C-reactive protein were investigated in 142 elderly patients with infections and 216 elderly patients without. CRP 7 - 20, 21 - 40 and 41 - 60 mg/L were stratified, the index of diagnostic test counted.</p><p><b>RESULTS</b>Concentrations of CRP in patients with different diseases were upper respiratory tract infection 36.9 mg/L +/- 28.9 mg/L, acute bronchitis 30.1 mg/L +/- 28.1 mg/L, pneumonia 55.9 mg/L +/- 32.9 mg/L, urinary infection 49.0 mg/L +/- 27.6 mg/L and enteritis 39.3 mg/L +/- 35.6 mg/L. They were all higher than those in control group (5.2 mg/L +/- 2.9 mg/L, P < 0.001). Stratified analysis disclosed that the specificity of CRP was 83.3% - 99.0% for diagnostic infection disease. The positive likelihood ratio (LR) of 7 - 20, 21 - 40 and 41 - 60 mg/L were 3.6, 27.0 and 128.0, respectively.</p><p><b>CONCLUSION</b>C-reactive protein was an important marker to diagnose elderly patients with infections.</p>
