Radiographic resolution of community-acquired bacterial pneumonia in the elderly.

OBJECTIVES

To investigate the radiographic clearance of proven community-acquired nontuberculous bacterial pneumonia in nonimmunocompromised older patients to provide working estimates of the rate of radiographic resolution as a function of the patient cumulative comorbidities, extent of initial radiographic involvement, functional status, and causative pathogens.

DESIGN

A prospective study.

PARTICIPANTS

Seventy-four patients aged 70 and older, consecutively admitted to a hospital for community-acquired bacterial pneumonia.

SETTING

A university-affiliated teaching hospital.

MEASUREMENTS

Chest radiographs were performed every 3 weeks from the date of admission for a total period of 12 weeks or until all radiographic abnormalities had resolved or returned to baseline.

RESULTS

Sixty-four patients (86%) completed the study. The rate of radiographic clearance was estimated at 35.1% within 3 weeks, 60.2% within 6 weeks, and 84.2% within 12 weeks. Radiographic resolution was significantly slower for those with high comorbidity index, bacteremia, multilobar involvement, and enteric gram-negative bacilli pneumonias. Multivariate regression analysis demonstrated that the comorbidity index (relative risk for clearance=0.67 per class index, P<.001) and multilobar disease (relative risk for clearance=0.24 for more than one lobe, P<.001) had independent predictive value (Cox proportional hazards regression model) on the rate of resolution.

CONCLUSION

The radiographic resolution of nontuberculous bacterial pneumonia in the elderly should take into account the extent of lobar disease and the burden of underlying illnesses. A waiting period of 12 to 14 weeks is recommended for slowly resolving pneumonia to be considered nonresolving.