Background: Despite the wide distribution of different severity scoring systems for community-acquired pneumonia (CAP) patients, low-risk patients are frequently hospitalized, contrary to current recommendations. The aim of our study was to determine the rate, clinical characteristics, and outcome of low-risk patients with CAP admitted to our institution.
Methods: During an 18-month period, we prospectively screened all patients admitted to the Division of Internal Medicine with a presumptive diagnosis of CAP. Pneumonia Outcome Research Team (PORT) score and pneumonia severity index (PSI) were calculated for all patients during the first 24 h.
Results: A total of 591 patients had a diagnosis of CAP. Some 196 patients (33.1%) were low-risk (PSI class I, II), 98 (16.6%) intermediate (PSI III), and 297 (50.3%) high-risk patients (PSI IV, V). Patients in low-risk classes were younger (45.5+/-15.8 vs. 65.0+/-12.5 and 74.9+/-11.8 years, respectively, p<0.001) and had fewer background diseases. They had shorter hospitalizations than intermediate- and high-risk groups (4.4+/-3.2, 5.3+/-3.4, and 6.8+/-6.4 days, respectively, p<0.001). There was a significant difference in 30-day mortality between the different risk groups: 0% in the low-risk, 2.0% in the intermediate-risk, and 9.4% in the high-risk group (p<0.001).
Conclusion: The considerable proportion of low-risk patients hospitalized due to CAP was found to be comparable to the stable 30% rate reported in the literature. We conclude that physicians tend to opt for a wide safety range when considering a CAP patient hospitalization, rather than make a decision based only on severity score calculation.