RESULTS
We included 344 patients, 132 at HA and 212 at HB, of whom 74 (21.5%) had a PPE/PE− and 270 (78.5%) a PPE/PE+, with no significant difference in this proportion between the two hospitals (p = 0.35). In patients with PPE/PE+, the proportion of PPE/PE+1 and PPE/PE+2 was slightly different between HA (24.0% and 76.0%) and HB (37.6% and 62.4%) (p = 0.023).
Patients attended in the two hospitals were similar, with no significant differences in age, sex, year or month of admission, comorbidities, duration of fever, antibiotic treatment prior to admission to the referral hospital, affected side, peak leukocytes, neutrophils and C-reactive protein in blood, or proportion of patients with a pathogen identified by culture (E-table 1 and E-table 2). The only initial difference was that PPE/PE+ patients seen in HA were hospitalized with fewer days of fever and were more often transferred from another center compared to those in HB.
Table 1 shows the results of the analysis of the main variables, percentage of drained patients and LOS, stratified by effusion size. No patient with PPE/PE− was drained. The percentage of drained PPE/PE+ patients was significantly smaller in HA. On the other hand, LOS was significantly shorter in HA than in HB. E-table 1 presents a detailed analysis of other treatments and patient outcomes. Although cefotaxime was the most common antibiotic in both centers, more amoxicillin (alone or with clavulanic acid) was used in HA, and more clindamycin in PPE/PE+2 patients in HB. The duration of antibiotic treatment (intravenous and oral) was shorter in HA. There were no differences between the two centers in the use of fibrinolytics in patients who underwent pleural drainage, the administration of oxygen therapy or mechanical ventilation, the presence of pneumothorax, or the need for surgical treatment. PPE/PE+ patients were admitted to the PICU more frequently in HB than in HA. Fever lasted longer during hospitalization in HA patients than in HB patients, both in PPE/PE− and PPE/PE+, but the total duration of fever from onset of disease was longer only in PPE/PE+2.