[Prognostic factors of community acquired pneumonia in very old patients].

Background And Objective: To determine whether there are differences between the prognostic factors associated with 30-days mortality in patients 65-84 year-old and patients over 84 years hospitalized for community-acquired pneumonia (CAP).

Patients And Method: An observational study with retrospective data collection was carried out in a representative sample of all CAP in-patients of 27 general hospitals. Data regarding comorbidities, signs and symptoms on admission, radiological and laboratory examinations, and complications during hospitalization were recorded.

Results: 1,191 CAP patients were studied, 80.1% in the 65-84 age group and 19.9% in the over 84 age group. Mortality during the first 30 days was 11.9% in the younger group and 20.7% in the older (p < 0.001). In the younger group, the multivariate analysis showed the following independent prognostic factors: general discomfort (odds ratio [OR] = 3.93), respiratory rate > 30/min (OR = 5.02), atrial fibrillation (OR = 3.57), dementia (OR = 9.18), and hospitalization during the previous year (OR = 3.74). In the older group, independent prognostic factors were cancer (OR = 8.4) and renal failure (3.32). Age significantly modified the effect of altered mental state, tachypnea, tachycardia, hyperglycemia, and dementia on mortality.

Conclusions: In people over 84 years, except cancer and renal failure, classic CAP prognostic factors used in severity indexes do not distinguish those who will die from those who will not. Therefore, these factors must be interpreted with caution.