Can we use severity assessment tools to increase outpatient management of community-acquired pneumonia?

Outpatient management of community-acquired pneumonia (CAP) has several potential advantages, including significant cost-savings, a reduction in hospital-acquired infections and increased patient satisfaction. Despite the benefits, it is often difficult to identify which patients may be managed in the community without compromising patient safety. CAP severity scores, such as the pneumonia severity index (PSI) and the British Thoracic Society CURB65/CRB65 scores are designed to identify groups of patients at low risk of mortality who may be suitable for outpatient care. This review discusses the strengths and weaknesses of severity scores for use in determining site of care for patients with pneumonia. Use of the PSI in emergency departments has been shown to increase the proportion of patients treated in the community without increasing patient mortality or hospital readmissions. The CURB65 and CRB65 scores are less complex alternatives to the PSI that have been shown to perform similarly for prediction of 30-day mortality. All 3 scores identify populations at low risk of mortality who may be eligible for outpatient care. Nevertheless, a number of factors not included in severity scores may prevent discharge of these patients, including social factors, co-morbidities and severity markers not captured by severity scores. The limitations of severity scores are discussed along with recent attempts to improve predictive tools, with the development of new biomarkers and alternative scoring systems.