Quantifying and Financing the Nonbillable Workload of Outpatient Parenteral Antimicrobial Therapy (OPAT)-A Model for Assessing and Supporting Staffing Needs for OPAT Programs.

Abstract

Background: Outpatient parenteral antimicrobial therapy (OPAT) patients require complex multidisciplinary coordination outside billable visits. Predicting and funding sufficient staff capacity for OPAT programs is poorly understood.

Methods: OPAT episodes at our center from 1 January 2019 through 31 December 2020 were identified and categorized as requiring therapeutic drug monitoring (TDM) or non-TDM. Electronic health record (EHR) ambulatory encounters by infectious diseases clinic staff from OPAT start to 14 days after completion, or until study cessation, were extracted and categorized as billable, or nonbillable. Weekly registered nurse (RN) time for nonbillable tasks, stratified by monitoring acuity, was quantified using time-in-motion studies. RN overextension beyond a 40-hour week was used to calculate optimal staffing ratios. OPAT monitoring days were converted into projected profit margin attributable to hospitalization avoidance through OPAT program operations.

Results: During 2019-2020, 1645 OPAT courses were associated with 17 476 EHR infectious diseases clinic encounters; 15 163(87%) were nonbillable. TDM episodes were 24.9% by volume, but generated significantly more EHR encounters and workload hours than non-TDM episodes. An optimal ratio of 1 RN to support 436 OPAT episodes per year was derived within local context and monitoring acuity mix. An estimated $83 379 292 in cost savings, or $11 757 596 net revenue from admissions turnover, were attributable to 49 350 hospital bed-days avoided through OPAT.

Conclusions: A program staffing model was derived from multimethod evaluation of billable and nonbillable OPAT activities. Programs seeking to delineate and fund optimal staffing levels may perform similar analyses based on total volume, monitoring acuity of their OPAT panel, alongside a holistic assessment of financial benefits of OPAT to their organization.