We read with great interest the study of Calle et al.,1 recently published in Archivos de Bronconeumología, which analyzes the relationship between mortality and geriatric assessment parameters and standard clinical variables in very elderly patients with community-acquired pneumonia (CAP). The authors conclude their article by saying that age and other clinical, laboratory and geriatric assessment parameters, such as functional capacity, are useful for predicting mortality in the short term.

We have few points we would like to add to this report. In the last 10 years, the incidence of CAP seen in emergency departments in Spain has increased from 0.85% to 1.35% (P<.001).2 In total, 51% of CAPs were recorded in patients aged 70 years and older, and clinical presentation and mortality were significantly worse in this population than in patients aged 15–69 years (P<.001).2 These data have generated a growing awareness of the need for an accurate prognosis of mortality in elderly patients. Some biomarkers have proven useful as independent predictors of mortality in CAP patients,3,4 but reports of varying results in elderly individuals and other adults5 have raised questions about the usefulness of these biomarkers in patients of different ages.

These results motivated our group to retrospectively analyze the databases of some our studies3,4 in order to determine diagnostic factors for predicting mortality in the short term among CAP patients aged 75 years or older, or younger than 75, who were admitted to our hospital between November 2011 and July 2012. A total of 146 patients were included. Two subgroups were formed: group A (15–74 years: 79 cases, 54.1%) and group B (≥75 years: 67 cases, 45.9%). Some results are shown in Table 1. Despite the limitations of a small sample size and the retrospective, single-center nature of the analysis, we found mid-regional proadrenomedullin (MR-proADM) to be the most useful biomarker for predicting short-term mortality (intra-hospital and up to 30 days post-admission) in both group A and group B, and the one with the largest area under the receiver operating curve (AUC–ROC). Similarly, albeit to a lesser extent, procalcitonin levels significantly predicted differences in survival in both age groups and differences in mean numbers of survivors and non-survivors. No significant differences were observed between mean concentrations of C-reactive protein (non-survivors vs survivors) and the AUC–ROC curves are of little use, particularly in group B.

While awaiting the findings of a prospective study specifically designed to determine the utility of procalcitonin and, more importantly, MR-proADM for predicting mortality in elderly patients, initial determinations of these biomarkers in emergency departments could orient the prognosis of elderly patients with CAP. These patients often have a more deceptive and unclear clinical presentation, limited functional status and a high comorbidity burden. Although the role, utility and effectiveness of each biomarker will have to be defined, we believe they will be of use in determining the prognosis and care of elderly patients with CAP, and for making decisions on admission and the most appropriate destination of these fragile individuals.