Do pulmonary radiographic findings at presentation predict mortality in patients with community-acquired pneumonia?

BACKGROUND: Previous studies have reported conflicting results on whether pulmonary radiographic findings predict mortality for patients with community-acquired pneumonia (CAP). OBJECTIVE: To determine whether pulmonary radiographic findings at presentation are independently associated with 30-day mortality in patients with suspected CAP. METHODS: This study was conducted as part of the Pneumonia Patient Outcomes Research Team multicenter, prospective cohort study of ambulatory and hospitalized patients with clinical and radiographic evidence of CAP. For each patient with CAP, a structured data form was completed by a panel of radiologists to evaluate the radiographic pattern of infiltrate, number of lobes involved, presence of pleural effusion, and 8 other radiographic characteristics. Cox proportional hazards models were used to evaluate the independent association between radiographic findings and 30-day mortality, while controlling for patient demographic, clinical, and laboratory characteristics with a known association with this outcome. RESULTS: Of 2287 patients enrolled in the Pneumonia Patient Outcomes Research Team cohort study, 1906 patients (83.3%) had a pulmonary radiographic infiltrate confirmed by the radiology panel. Overall, 30-day mortality in this cohort was 4.9%. Univariate regression analyses demonstrated the following radiographic characteristics to be significantly associated with 30-day mortality: (1) bilateral pleural effusions (risk ratio [RR], 7.0; 95% confidence interval [CI], 3.9-12.6); (2) a pleural effusion of moderate or greater size (RR, 3.4; 95% CI, 1.4-8.4); (3) 2 or more lobes involved with infiltrate (RR, 2.5; 95% CI, 1.6-3.8); (4) bilateral infiltrate (RR, 2.8; 95% CI, 1.9-4.2); (5) bronchopneumonia (RR, 1.6; 95% CI, 1.0-2.7); and (6) air bronchograms (RR, 0.5; 95% CI, 0.2-0.9). Multivariate analysis of radiographic features and other clinical characteristics showed the presence of bilateral pleural effusions (RR, 2.8; 95% CI, 1.4-5.8) was independently associated with mortality. CONCLUSIONS: In patients with CAP, the presence of bilateral pleural effusions is an independent predictor of short-term mortality. This finding, which is available at presentation, can help guide physicians' assessment of prognosis in CAP.

Interobserver reliability of the chest radiograph in community-acquired pneumonia. PORT Investigators.

OBJECTIVE: To evaluate the interobserver reliability of pulmonary radiographic findings in patients with community-acquired pneumonia (CAP). DESIGN: A prospective, multicenter study. SETTING: Physician offices, medical walk-in clinics, emergency departments, and inpatient wards affiliated with three university hospitals, one community hospital, and one staff model health maintenance organization in three geographic areas. METHODS: Copies of the initial chest radiograph of patients suspected of having CAP were independently read by two staff radiologists at the coordinating university hospital. Interobserver reliability for the interpretation for radiographic findings was assessed by calculation of agreement rates and the kappa statistic. PARTICIPANTS: Adults (age > or = 18 years) with symptoms or signs of CAP and a pulmonary radiographic infiltrate documented by a local study site radiologist. RESULTS: Among the 282 patients whose initial pulmonary radiographs were evaluated, there was agreement between the two staff radiologists on the presence of infiltrate in 79.4% and on the absence of an infiltrate in 6.0% (kappa = 0.37; 95% confidence interval [CI] = 0.22 to 0.52). For the 224 patients with an infiltrate identified by both radiologists, there was further agreement that the infiltrate was unilobar in 41.5% and multilobar in 33.9% (kappa = 0.51; 95% CI = 0.28 to 0.62), pleural effusion was present in 10.7% and absent in 73.2% (kappa = 0.46; 95% CI = 0.33 to 0.50), and the infiltrate was alveolar in 96.3% of patients and interstitial in no patients (kappa = -0.01; 95% CI = -0.03 to 0.00). Among the 210 patients with an alveolar infiltrate, both radiologists classified the infiltrate as lobar in 74.6% and bronchopneumonia in 2.4% (kappa = 0.09; 95% CI = -0.04 to 0.22), and agreed on the presence of air bronchograms in 7.6% and their absence in 52.9% (kappa = 0.01; 95% CI = -0.13 to 0.15). CONCLUSION: In patients with CAP, two university radiologists identified the presence of infiltrate, multilobar disease, and pleural effusion with fair to good interobserver reliability. However, interobserver reliability for the pattern of infiltrate and the presence of air bronchograms was poor.