Outcome Pneumonia is diagnosed in the presence of 2 major clinical signs: increased sputum production and pneumonic changes in the CXR (according to radiologist report), or in the presence of one major sign and 2 of the following minor clinical signs: raised or depressed white cell count, hypoxia at room air (PaO2 <92%) and body temperature greater than 38%. When the criteria for pneumonia are fulfilled, the trial will be terminated.