RADIOGRAPHIC RESOLUTION OF COMMUNITY-ACQUIRED PNEUMONIA

Clinicians are frequently faced with patients in whom the radiographic resolution of community-acquired pneumonia seems delayed. Previous st udies of radiographic resolution of the disease have yielded conflicti ng results. We prospectively assessed the radiographic resolution of p neumonia in 81 non-immunocompromised patients, presenting to the emerg ency room and ambulatory clinics of a large university hospital, who m et clinical and radiographic criteria for pneumonia. Serial chest radi ographs were obtained every 2 wk for an initial period of 8 wk, and th en every 4 wk until 24 wk had passed, or until all radiographic abnorm alities had cleared. Forty-one of the 81 patients (50.6%) demonstrated complete clearance after 2 wk. Fifty of the 75 patients (66.7%) follo wed to 4 wk demonstrated complete clearance. The rate of clearance was inversely correlated with age (p < 0.001) and involvement of single v ersus multiple lobes (p < 0.0001) (log-rank test). Clearance was faste r in those patients treated as outpatients (3.8 wk versus 9.1 wk, p = 0.03) and in patients who were nonsmokers (4.5 wk versus 8.4 wk, p = 0 .05) (log-rank test). Multivariate regression analysis demonstrated th at only age (relative risk for clearance, +0.79 per decade) and single versus multiple robes involved (relative risk for clearance, 0.55 for more than one lobe) had independent predictive value (Cox proportiona l hazards regression model). The radiographic resolution of pneumonia occurs more rapidly in younger patients and in those with only a singl e lobe involved. Our estimates of the likelihood of radiographic clear ance as a function of age should prove useful for individualizing the timing of radiographic follow-up of pneumonia, and of further investig ation when resolution seems delayed.