Failure of a pharmacist-initiated antimicrobial step-down protocol to impact physician prescribing behavior or patient outcomes: A quasi-experimental, cross-over study

Abstract

Background: Intravenous (IV) to oral (PO) conversion may expedite hospital discharge and decrease costs. Most IV-to-PO programs include antimicrobials with highly-bioavailable PO formulations, allowing sequential interchanges. Our aim was to evaluate clinical and economic outcomes of a pharmacist-initiated antimicrobial step-down protocol whereby intravenous (IV) antimicrobials were switched to different oral (PO) antimicrobials.

Methods: A 12-month quasi-experimental, cross-over study was conducted on a 45-bed adult general medicine ward in two populations (A & B) receiving an IV antimicrobial for ≥ 48 hours in three phases: baseline (Phase 1); step-down protocol in Group A only (Phase 2); and step-down protocol in Group B, withdrawn from Group A (Phase 3). A step-down conversion form was used by pharmacists to screen patients for eligibility. If eligible, the form was placed in the medical record to be completed by the physician. Outcomes reported after step-down eligibility included percent receiving step-down conversion; length of stay; therapy duration; IV complications; clinical cure; and antimicrobial and hospitalization costs.

Results: 2,635 patients were screened. Of 595 included patients, 33.6% (n=98) and 32% (n=97) were eligible for step-down in Groups A and B, respectively. During Phase 2, 42.1% of the eligible Group A and 28.6% of the eligible Group B patients were switched to step-down therapy (p=0.12). No significant difference existed between the groups for length of stay; duration of therapy; IV complications; clinical cure; and costs.  Similar results were observed in Phase 3. Post hoc analyses showed those receiving step-down conversion had shorter stays (p=0.02) and decreased hospitalization costs (p=0.006).

Conclusions: Approximately 60%-75% of eligible patients did not receive step-down conversion. The step-down protocol was labor-intensive and poorly accepted. Successful step-down programs must anticipate these challenges.  Step-down was associated with shorter stays and decreased costs.