Guideline tyranny: primum non nocere.

Toward the end of the 20th century, clinical guidelines proliferated that had the laudable aim of bringing best practices to bear on the unnecessary variability of medical care. New guidelines have continued to appear that span the entire spectrum of medical and surgical practice. Meanwhile, older guidelines have been continually updated. Community-acquired pneumonia (CAP), one of the most common conditions to lead to hospitalization in the United States, has been increasing among adults aged 165 years [1], and CAP was the focus of one of the earliest clinical guidelines. Several national professional societies, including the Infectious Diseases Society of America and the Amer-ican Thoracic Society, first published their own guidelines on CAP and later collaborated on consensus-driven guidelines [2]. In 1997, a single publication on the treatment of CAP in elderly patients provided data indicating that patients with CAP had improved survival rates if they received antimicrobial therapy р8 h after first being seen in an emergency department setting [3]. This retrospective study involved 14,069 patients and demonstrated a 15% lower odds of mortality during the subsequent 30 days if antibiotics were administered within 8 h. On the basis of the results of this study, the Health Care Finance Agency (now the Centers for Medicare and Medicaid Services [CMS]), promulgated the recommendation that all patients with CAP be treated within 8 h after admission to the emergency department. In 2004, the recommended duration until treatment was reduced to р4 h, in response to a CMS-sponsored study that demonstrated slightly improved mortality rates in older patients who received antibiotics within a 4-h window [4]. Critics of the CMS-sponsored study point to several inconsistencies, such as the increased mortality rate if antibiotics are given р2 h after admission but decreased mortality rate if they are given at 4 h [5]. They also point out that antibiotics take several days to impact the outcome of pneumococcal pneumonia and offer alternative explanations for the study findings. One such explanation includes the possibility that altered mental status and atypical presentations of CAP—particu-larly common phenomena in elderly pa-tients—can be markers of underlying co-morbidities that, in and of themselves, predict a poor prognosis. These comor-bidities and atypical presentations, rather than the delay in antibiotic administration that they often occasion, may be the causes of adverse outcomes. In addition, patients who receive antibiotics in a timely manner at presentation to the hospital may demonstrate better outcomes not just …