Inflammatory responses predict long-term mortality risk in community-acquired pneumonia

Long-term outcomes in patients surviving community-acquired pneumonia (CAP) are still incompletely understood. This study investigates the association of clinical parameters and blood markers with long-term mortality. We prospectively followed 877 CAP patients from a previous multicentre trial for 18 months follow-up and investigated all-cause mortality following hospital discharge. Overall mortality was 17.3% (95% CI 14.8-19.8%) with a 12.8% (95% CI 10.9-15.0%) mortality incidence rate per year. Initial risk assignment using the Pneumonia Severity Index was accurate during the 18 month follow-up. Multivariable regression models (hazard ratio, 95% CI) designated the following as independent risk factors for long-term mortality: male sex (1.7, 1.2-2.5); chronic obstructive pulmonary disease (1.5, 1.1-2.1); neoplastic disease (2.5, 1.7-3.7); and highest quartile of peak pro-adrenomedullin level (3.3, 1.7-6.2). Initial presentation with temperature<38.7°C (0.4, 0.2-0.6), chills (0.6, 0.4-0.99) and highest quartile of the inflammatory marker C-reactive-protein (0.3, 0.2-0.5) were independent protective factors. A weighted risk score based on these variables showed good discrimination (area under receiver operating characteristic curve 0.78, 95% CI 0.74-0.82). Pronounced clinical and laboratory signs of systemic inflammatory host response upon initial hospital stay were associated with favourable long-term prognosis. Further studies should address whether closer monitoring of high-risk CAP patients after hospital discharge favourably impacts long-term mortality.