Evaluation of outcomes in community-acquired pneumonia: a guide for patients, physicians, and policy-makers.

Community-acquired pneumonia (CAP) is a key target for research and quality improvement in acute medicine. However, many of the outcome measures used in prognostic and antibiotic studies are not validated and do not capture features of outcome that are important to patients. Substitutes for traditional outcome measures include a recently validated patient-based symptom questionnaire (the CAP-Sym) and process-of-care measures. The interpretation of outcomes also depends on the quality of the study design and methods used. This paper discusses the advantages and disadvantages of outcome, process-of-care, and economic measures in CAP and the interpretation of these measures in randomised and observational studies. A core set of measures for use in clinical CAP research and performance measurement is proposed.