Blood cultures for community-acquired pneumonia: are they worthy of two quality measures? A systematic review.

BACKGROUND Obtaining blood cultures (BCs) for patients hospitalized with community-acquired-pneumonia (CAP) has been recommended by experts and used as a measure of quality of care. However, BCs are infrequently positive in these patients and their effect on clinical management has been questioned. PURPOSE We performed a systematic review of the literature to determine the impact of BCs on clinical management in CAP requiring hospitalization and thus its appropriateness as a quality measure. DATA SOURCES We searched MEDLINE, MEDLINE In-Process, and the Cochrane databases for English-language studies that reported the effect of BCs on management of adults hospitalized with CAP. We also searched the reference lists of included studies and background articles and asked experts to review our list for completeness. STUDY SELECTION Studies were chosen if they included adults admitted to the hospital with CAP, BCs were obtained at admission, and BC-directed management changes were reported. DATA EXTRACTION We abstracted study design, BC positivity, and frequency of BC-directed management changes. DATA SYNTHESIS Fifteen studies, all with observational cohort design, were identified and reviewed. Two included only patients with BCs positive for pneumococcus, yielding 13 studies for the primary analysis. BCs were true-positive in 0% to 14% of cases. They led to antibiotic narrowing in 0% to 3% of patients and to antibiotic broadening ultimately associated with a resistant organism in 0% to 1% of patients. CONCLUSIONS BCs have very limited utility in immunocompetent patients hospitalized with CAP. Pneumonia quality measures that include BCs should be reassessed.