TY - JOUR T1 - Assessment of pneumonia severity: a European perspective JF - European Respiratory Journal JO - Eur Respir J SP - 6 LP - 8 DO - 10.1183/09031936.06.00130205 VL - 27 IS - 1 AU - S. Ewig AU - A. Torres AU - M. Woodhead Y1 - 2006/01/01 UR - http://erj.ersjournals.com/content/27/1/6.abstract N2 - Where to treat a patient with community-acquired pneumonia (CAP) is probably the most important decision in the management of this condition. This is true in terms of patient outcomes and, definitely, in terms of costs. Therefore, all current European and American guidelines agree that the assessment of severity is the starting point in the management algorithm 1–5. If the assessment is so crucial, what are the criteria physicians can rely on? In 1997, Fine et al. 6 introduced the pneumonia severity index (PSI). The PSI consists of 20 variables reflecting age, sex, residence, comorbidity and acute pneumonia-associated morbidity. These variables were derived from and validated in >50,000 patients, the largest database ever studied in the history of pneumonia research. The original role of the PSI was to identify those patients at a low risk of mortality who, therefore, could safely be treated as outpatients. Three risk classes were identified with a very low-risk 30-day mortality of 1–3%, a fourth with an increased risk of ∼8%, and a fifth with a high risk of ∼30%. The PSI was subsequently confirmed to make valid predictions of mortality by several authors, although in some reports mortality rates were somewhat lower in the highest risk group 7–9. Finally, the PSI was also shown to predict long-term outcomes of CAP 10. A major limitation of the PSI is the unbalanced impact of age on the score, resulting in a potential underestimation of severe pneumonia, particularly in younger otherwise healthy individuals 9. Nevertheless, the PSI is currently recommended as a tool of severity assessment in the Infectious Diseases Society of America guidelines 2, 3. In a previous landmark study by the British Thoracic Society, four variables reflecting acute pneumonia-associated morbidity were shown to be predictive of … ER -