The study included 32 emergency departments at hospitals in Connecticut and Pennsylvania. Eight of the hospitals were randomized to use a low-intensity strategy to implement the PSI-based triage scheme. The staffs received a guideline that said that low-risk, non-hypoxemic patients could be treated as outpatients. Twelve hospitals used a moderate-intensity strategy. In addition to receiving this guideline, the state PRO gave the emergency department director data on how many pneumonia patients in the past fell into the low-risk category. Each director also had to devise a quality improvement plan, and emergency-department physicians went to an educational session on implementing the guidelines. The other 12 hospitals received a high-intensity intervention. In addition to the moderate-intensity program, they also received a paper algorithm to calculate the PSI score, and each physician on the emergency department staff received patient-specific audit information.
These emergency departments also used a plan-do-study-act cycle every two months to help improve guideline adherence. During January 15, 2001 through December 31, 2001, 3,450 patients appeared at these hospitals with CAP. Of these, 1,874 were diagnosed as low-risk patients with a PSI of I-III. The fraction of these patients who were treated as outpatients was 38.2 percent at the low-intensity intervention hospitals, 62.4 percent at the moderate-intensity hospitals, and 62 percent at the high-intensity hospitals. When the data were adjusted for PSI risk class, the odds ratio for a patient being treated as an outpatient was one for the low-intensity intervention hospitals, three for the moderate-intensity hospitals, and 2.4 for the high-intensity hospitals.
The death rate among patients was similar in all three groups, ranging from 2.1 percent at the low-intensity-intervention hospitals to 1.7 percent at the high-intensity hospitals. The need for re-hospitalization was also similar among the hospitals in all three intervention groups, ranging from five percent in the moderate-intensity group to 6.4 in the high-intensity group.