Erythrocyte sedimentation rate and C-reactive protein compared in the elderly. 
The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) concentrations were studied in 101 elderly individuals (mean age 72 y) to determine their utility as diagnostic aids in subjects with underlying infection/inflammation.  Whereas ESR and CRP were both significantly increased in patients with infection or inflammation, or both, analysis of variance indicated that those subjects still alive six months later had significantly lower ESR values.  Analysis of sensitivity, specificity, and positive predictive values indicated that neither test satisfactorily discriminated between patients with and those without ongoing active or chronic disease.  Receiver-operating characteristic curve analysis confirmed the low true-positive/false-positive ratios of both ESR and CRP.  In the elderly, neither CRP nor ESR has distinct advantages over the other, and both tests evidently have limited utility.