Community-acquired pneumonia: 2012 history, mythology, and science.

Pneumonia remains one of the major disease entities practicing physicians must manage. It is a leading cause of infection-related morbidity and mortality in all age groups, and a leading cause of death in those older than 65 years of age. Despite its frequency and importance, clinical questions have remained in the therapy of community-acquired pneumonia including when to start antibiotics, when to stop them, who to treat, and what agents to use. Answers to these questions have involved historical practice, mythology, and science-sometimes good science, and sometimes better science. How clinical decisions are made for patients with community-acquired pneumonia serves as an illustrative model for other problem areas of medicine and allows for insight as to how clinical decisions have been made and clinical practice established.