Predictors of timely antibiotic administration for patients hospitalized with community-acquired pneumonia from the cluster-randomized EDCAP trial

Abstract

Introduction: To identify factors associated with timely initiation of antibiotic therapy for patients hospitalized with pneumonia.

Design: Secondary analysis of a cluster-randomized, controlled trial.

Setting: Thirty- two emergency departments (EDs) in Pennsylvania and Connecticut.

Subjects: Patients with a clinical and radiographic diagnosis of community-acquired pneumonia.

Interventions: From January to December 2001, EDs were randomly allocated to guideline implementation strategies of low (n = 8), moderate (n = 12), and high intensity (n = 12) to improve the initial site of treatment and the performance of evidence-based processes of care. Our primary outcome was antibiotic initiation within 4 hours of presentation, which at that time was the recommended process of care for inpatients.

Results: Of the 2076 inpatients enrolled, 1632 (78.6%) received antibiotic therapy within 4 hours of presentation. Antibiotic timeliness ranged from 55.6% to 100% (P < 0.001) by ED and from 77.0% to 79.7% (P = 0.2) across the 3 guideline implementation arms. In multivariable analysis, heart rate > or =125 per minute (OR = 1.6, 95% CI 1.1-2.3), respiratory rate > or =30 per minute (OR = 2.3, 95% CI 1.6-3.4), and aspiration pneumonia (OR = 3.7, 95% CI 1.1-12.7) were positively associated with timely initiation of antibiotic therapy, whereas a hematocrit <30% (OR = 0.6, 95% CI 0.4-1.0) was negatively associated with this outcome.

Conclusions: Timely initiation of antibiotic therapy is associated primarily with patient-related factors that reflect severity of illness at presentation. Although this study demonstrates an opportunity to improve performance on this quality measure in nearly one quarter of inpatients with pneumonia, we failed to identify any modifiable patient, provider, or hospital level factors to target in such quality improvement efforts.

Figure 1. Patient Enrollment for the EDCAP Trial and Resulting Guideline Compliance with Timely Antibiotic Administration

In the EDCAP Trial, a total of 4506 patients were eligible, 3615 were initially enrolled, and 414 were subsequently excluded. Reasons for exclusion included: (1) discovery of one or more exclusion criteria not recognized at presentation (n=163); (2) enrollment protocol or informed consent violations (n=163); (3) patient withdrawal or death in the emergency department before assignment of initial site of treatment (n=33); (4) incomplete information for PSI risk class (n=37); and (5) incomplete medical record review (n=18)., The most common reasons for protocol violations were: (1) enrollment of patients managed by a study investigator (n=47); (2) previous study enrollment (n=32); and (3) participation in a competing research protocol (n=29). Overall, of the 3201 patients who comprised the entire study cohort to assess initial processes of care, 2076 were treated as inpatients, of whom 1632 (78.6%) received initial antibiotic therapy within 4 hours of presentation.

Figure 2. Site Specific Timeliness of Antibiotic Therapy by Intervention Arm

This graph shows the site-specific proportions (X's) of patients who received initial antibiotic therapy within 4 hours of presentation of all 32 sites randomized to the low intensity (n=8), moderate intensity (n=12), and high intensity (n=12) intervention arms of the EDCAP Trial. The diamonds denote the corresponding proportions for all inpatients within each intervention arm.