PT  - JOURNAL ARTICLE
AU  - Christian S. Marchello
AU  - Mark H. Ebell
AU  - Ariella P. Dale
AU  - Eric T. Harvill
AU  - Ye Shen
AU  - Christopher C. Whalen
TI  - Signs and Symptoms That Rule out Community-Acquired Pneumonia in Outpatient Adults: A Systematic Review and Meta-Analysis
AID  - 10.3122/jabfm.2019.02.180219
DP  - 2019 Mar 01
TA  - The Journal of the American Board of Family
                Medicine
PG  - 234--247
VI  - 32
IP  - 2
4099  - http://www.jabfm.org/content/32/2/234.short
4100  - http://www.jabfm.org/content/32/2/234.full
SO  - J Am Board Fam Med2019 Mar 01; 32
AB  - Background: A systematic review of clinical decision rules to identify patients at low risk for community-acquired pneumonia (CAP) has not been previously presented in the literature.Methods: A systematic review of MEDLINE for prospective studies that used at least 2 signs, symptoms, or point-of-care tests to determine the likelihood of CAP. We included studies that enrolled adults and adolescents in the outpatient setting where all or a random sample of patients received a chest radiograph as the reference standard. We excluded retrospective studies and studies that recruited primarily patients with hospital-acquired CAP.Results: Our search identified 974 articles, 12 of which were included in the final analysis. The simple heuristic of normal vital signs (temperature, respiratory rate, and heart rate) to identify patients at low risk for CAP was reported by 4 studies and had a summary estimate of the negative likelihood ratio (LR−) of 0.24 (95% CI, 0.17 to 0.34) and a sensitivity of 0.89 (95% CI, 0.79 to 0.94). The simple heuristic of normal vital signs combined with a normal pulmonary examination to identify patients at low risk for CAP was reported by 3 studies, and had a summary estimate of LR− of 0.10 (95% CI, 0.07 to 0.13) with an area under the receiver operating characteristic curve of 0.92.Conclusions: Adults with an acute respiratory infection who have normal vital signs and a normal pulmonary examination are very unlikely to have CAP. Given a baseline CAP risk of 4%, these patients have only a 0.4% likelihood of CAP.