Adults with symptoms of pneumonia: a prospective comparison of patients with and without infiltrates on chest radiography

Objective: Most studies on patients hospitalized with community-acquired pneumonia (CAP) require confirmation of an infiltrate by chest radiography, but in practice admissions are common among patients with symptoms of pneumonia without an infiltrate (SPWI). The aim of this research was to compare clinical characteristics, microbial etiology, and outcomes among patients with CAP and SPWI. Methods: Adults suspected of CAP were prospectively recruited at Landspitali University Hospital over a 1year period, 2018 to 2019. The study was population based. Those admitted with two or more of the following symptoms were invited to participate: temperature >= 38? or &<= 36?, sweating, shaking/chills, chest pain, a new cough, or new onset of dyspnea. Primary outcome was mortality at 30 days and one year. Results: Six hundred twenty-five cases were included, 409 with CAP and 216 with SPWI; median age was 75 (interquartile range [IQR] 64-84) and 315 (50.4%) were females. Patients with CAP were more likely to have fever (>= 38? ) (66.9% [273/408]) vs. 49.3% (106/215), p < 0.001), a higher CRP (median 103 [IQR 34 -205] vs. 55 (IQR 17-103), p < 0.001), identification of Streptococcus pneumoniae (18.0% [64/355]) vs. 6.3% (10/159) of tested, p = 0.002) and to receive antibacterial treatment (99.5% [407/409]) vs. 87.5% (189/216), p < 0.001) but less likely to have a respiratory virus detected (25.4% [33/130]) vs. 51.2% (43/84) of tested, p < 0.001). The adjusted odds ratios for 30-day and 1 year mortality of SPWI compared to CAP were 0.86 (95% CI 0.40-1.86) and 1.46 (95% CI 0.92-2.32), respectively. Discussion: SPWI is a common cause of hospitalization and despite having fever less frequently, lower inflammatory markers, and lower detection rate of pneumococci than patients with CAP, mortality is not significantly different. Kristj?an Godsk Roeurognvaldsson, Clin Microbiol Infect 2023;29:108.e1-108.e6 (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases.

Automated summary

This study aimed to compare the clinical characteristics, microbial etiology, and outcomes between patients hospitalized with community-acquired pneumonia (CAP) and those with symptoms of pneumonia without an infiltrate (SPWI). The results showed that despite having fewer fevers, lower inflammatory markers, and a lower detection rate of pneumococci, patients with SPWI had similar mortality rates to those with CAP.