Hospital admission decision for patients with community-acquired pneumonia: variability among physicians in an emergency department

Study objective: We examine variability among emergency physicians in rate of hospitalization for patients with pneumonia and the effect of variability on clinical outcomes.

Methods: We studied 2,069 LDS Hospital emergency department (ED) patients with community-acquired pneumonia who were aged 18 years or older during 1996 to 2006, identified by International Classification of Diseases, Ninth Revision coding and compatible chest radiographs. We extracted vital signs, laboratory and radiographic results, hospitalization, and outcomes from the electronic medical record. We defined "low severity" as PaO(2)/FiO(2) ratio greater than or equal to 280 mm Hg, predicted mortality less than 5% by an electronic version of CURB-65 that uses continuous and weighted elements (eCURB), and less than 3 Infectious Disease Society of America-American Thoracic Society 2007 severe pneumonia minor criteria. We adjusted hospitalization decisions and outcomes for illness severity and patient demographics.

Results: Initial hospitalization rate was 58%; 10.7% of patients initially treated as outpatients were secondarily hospitalized within 7 days. Median age of admitted patients was 63 years; median eCURB predicted mortality was 2.65% (mean 6.8%) versus 46 years and 0.93% for outpatients. The 18 emergency physicians (average age 44.9 [standard deviation 7.6] years; years in practice 8.4 [standard deviation 6.9]) objectively calculated and documented illness severity in 2.7% of patients. Observed 30-day mortality for inpatients was 6.8% (outpatient mortality 0.34%) and decreased over time. Individual physician admission rates ranged from 38% to 79%, with variability not explained by illness severity, time of day, day of week, resident care in conjunction with an attending physician, or patient or physician demographics. Higher hospitalization rates were not associated with reduced mortality or fewer secondary hospital admissions.

Conclusion: We observed a 2-fold difference in pneumonia hospitalization rates among emergency physicians, unexplained by objective data.