Outpatient Parenteral Antimicrobial Therapy in a Safety Net Hospital: Opportunities for Improvement

Open Forum Infect Dis. 2024 Apr 3;11(5):ofae190. doi: 10.1093/ofid/ofae190. eCollection 2024 May.


Background: Outpatient parenteral antimicrobial therapy (OPAT) is a safe and cost-effective transitional care approach administered via different delivery models. No standards exist for appropriate OPAT program staffing. We examined outcomes of patients receiving OPAT via different care models to identify strategies to improve safety while reducing health care overuse.

Methods: Retrospective demographic, clinical, and outcome data of patients discharged with OPAT were reviewed in 2 periods (April-June 2021 and January-March 2022; ie, when staffing changed) and stratified by care model: self-administered OPAT, health care OPAT, and skilled nursing facility OPAT.

Results: Of 342 patients, 186 (54%) received OPAT in 2021 and 156 (46%) in 2022. Hospital length of stay rose from 12.4 days to 14.3 in 2022. In a Cox proportional hazards regression model, visits to the emergency department (ED) within 30 days of OPAT initiation (hazard ratio, 1.76; 95% CI, 1.13-2.73; P = .01) and readmissions (hazard ratio, 2.34; 95% CI, 1.22-4.49; P = .01) increased in 2022 vs 2021, corresponding to decreases in OPAT team staffing. Higher readmissions in the 2022 cohort were for reasons unrelated to OPAT (P = .01) while readmissions related to OPAT did not increase (P = .08).

Conclusions: In a well-established OPAT program, greater health care utilization-length of stay, ED visits, and readmissions-were seen during periods of higher staff turnover and attrition. Rather than blunt metrics such as ED visits and readmissions, which are influenced by multiple factors besides OPAT, our findings suggest the need to develop OPAT-specific outcome measures as a quality assessment tool and to establish optimal OPAT program staffing ratios.

Keywords: ED visits; OPAT care models; outpatient parenteral antimicrobial therapy; readmissions; staffing ratio.