Outpatient Versus Inpatient Intravenous Antimicrobial Therapy: A Population-Based Observational Cohort Study of Adverse Events and Costs

Early Oral Step-Down Versus Continued Intravenous Antibiotic Treatment of Complicated Intra-Abdominal Infection

Background: Complicated intra-abdominal infections (cIAIs) require a combined tactic, of source control and antimicrobial therapy. This study aimed to evaluate the safety and efficacy of oral step-down antimicrobial therapy in cIAIs after initial intravenous (IV) antimicrobial therapy. Methods: This retrospective cohort study included hospitalized adult patients diagnosed with a cIAI who received more than seven days of IV therapy from March 2017 to October 2021. Exclusion criteria included primary/peritoneal dialysis-related peritonitis, necrotizing pancreatitis, fistulizing inflammatory bowel disease, or upper gastrointestinal tract infection. Patients were assigned into two groups: IV-only or oral step-down therapy. The primary outcome was infection recurrence, defined as re-initiation of antimicrobial agents after a treatment-free period of more than or equal to three days. Secondary outcomes included treatment escalation, repeat source control procedure, treatment-related complications, and all-cause mortality. Results: The cohort consisted of 248 patients (199 IV-only and 49 oral step-down). Patients receiving IV-only therapy had a shorter median antimicrobial duration than the oral step-down group (13 vs. 23 d; p <0.0001). Infection recurrence occurred in 26 (13.1%) and 6 (12.2%) patients in the IV-only and oral step-down groups, respectively (p = 0.88). Treatment escalation, repeat source control, and 28-day mortality were similar between groups. Oral step-down therapy resulted in more adverse drug events (10.2% vs. 3.0%; p = 0.04). Discussion: Transition to oral step-down after initial IV therapy had a similar rate of infection recurrence as IV-only therapy but was associated with a longer duration of antimicrobial therapy and an increased rate of adverse drug reactions. Larger randomized non-inferiority studies are needed to confirm this approach.

Cost comparison analysis of continuous versus intermittent antimicrobial therapy infusions in inpatient and outpatient care: real-world data from Finland

OBJECTIVE

This study compared the costs and nursing time associated with the delivery of continuous infusion of antibiotics via elastomeric infusion pumps (EIP) versus conventional intermittent infusion (CII) across different care pathways.

DESIGN

Retrospective real-world data informed a cost comparison analysis that compared costs and nursing hours between infusion of antibiotics via EIP versus CII across eight care pathways in inpatient or outpatient care during infection episodes. Real-world data were obtained from patients treated within a year with parenteral antimicrobial therapy in Päijät-Häme Region, Finland.

SETTING

Inpatient care with hospital admission and outpatient care at hospital at home in Päijät-Häme Region in Finland.

PARTICIPANTS

3778 patients with a total of 4214 infection episodes treated with intravenous antimicrobial therapy.

INTERVENTIONS

Eight treatment strategies with various combinations of EIP and CII administered in inpatient or outpatient care.

PRIMARY AND SECONDARY OUTCOME MEASURES

Direct costs and nursing time.

RESULTS

Skin and soft tissue infections accounted for the highest number of episodes treated with EIP overall (30.8%; 74 out of 240 episodes) and in outpatient care specifically (53.3%; 128 out of 240 episodes). Compared with inpatient care costs with CII (€4590 per episode), treating skin and soft tissue infections in outpatient care with EIP or CII incurred only 24% (€1104) and 35% (€1620) of the costs, respectively. Across all treatment strategies and infections studied, the use of EIP consistently required less nursing time. The highest nursing time in the outpatient care was observed in sepsis episodes treated with CII (37 hours with CII vs 7 hours with EIP per episode).

CONCLUSION

Delivery of antimicrobial therapy using continuous infusions with EIP instead of CII can significantly decrease the nursing time and cost in both inpatient and outpatient care. For skin and soft tissue infections and sepsis, the utilisation of EIP is a cost-saving option in outpatient care compared with the use of CII.

Current practices and challenges of outpatient parenteral antimicrobial therapy: a narrative review

Extended hospitalization for infection management increases inpatient care costs and the risk of healthcare-associated adverse events, including infections. The growing global demand for healthcare, the diminishing availability of hospital beds and an increasing patient preference for care within their own home have been the primary drivers of the expansion of hospital-in-the-home programmes. Such programmes include the use of IV antimicrobials in outpatient settings, known as outpatient parenteral antimicrobial therapy (OPAT). However, OPAT practices vary globally. This review article aims to describe the current OPAT practices and challenges worldwide. OPAT practice begins with patient evaluation and selection using eligibility criteria, which requires collaboration between the interdisciplinary OPAT team, patients and caregivers. Depending on care requirements, eligible patients may be enrolled to various models of care, receiving medication by healthcare professionals at outpatient infusion centres, hospital clinics, home visits or through self-administration. OPAT can be used for the management of many infections where an effective oral treatment option is lacking. Various classes of parenteral antimicrobials, including β-lactams, aminoglycosides, glycopeptides, fluoroquinolones and antifungals such as echinocandins, are used globally in OPAT practice. Despite its benefits, OPAT has numerous challenges, including complications from medication administration devices, antimicrobial side effects, monitoring requirements, antimicrobial instability, patient non-adherence, patient OPAT rejection, and challenges related to OPAT team structure and administration, all of which impact its outcome. A negative outcome could include unplanned hospital readmission. Future research should focus on mitigating these challenges to enable optimization of the OPAT service and thereby maximize the documented benefits for the healthcare system, patients and healthcare providers.

Outpatient parenteral antimicrobial therapy (OPAT) across the world: a comparative analysis-what lessons can we learn?

This paper presents a comparative analysis of Outpatient Parenteral Antimicrobial Therapy (OPAT) structures and delivery options across different countries. OPAT, a cost-effective alternative to inpatient care for patients requiring IV antimicrobial therapy, has demonstrated multiple benefits such as patient satisfaction, economic cost savings, and reduced hospital-acquired infections. Despite these advantages, there is considerable international variation in OPAT use and implementation. By examining the OPAT structures of multiple countries, we aim to identify areas of variation and explore opportunities for expansion and improvement of OPAT services.

[Outpatient parenteral anti-infective therapy (OPAT)]

Outpatient parenteral anti-infective therapy (OPAT) involves the administration of intravenous anti-infectives outside a hospital setting. This shortens the inpatient stay and leads to a reduction in treatment costs, fewer instances of nosocomial infections and enhanced quality of life for the patient.

Barriers and facilitators for the implementation and expansion of outpatient parenteral antimicrobial therapy: a systematic review

Outpatient parenteral antimicrobial therapy (OPAT) has been expanding in recent years and serves as a viable solution in reducing the shortage of hospital beds. However, the wider implementation of OPAT faces numerous challenges. This review aimed to assess implementation barriers and facilitators of OPAT services. Studies describing barriers and facilitators of the OPAT service were retrieved from PubMed, Scopus, MEDLINE, EMBASE, CINAHL, Cochrane Library, Web of Science Proceedings, International Pharmaceutical Abstracts and PsycINFO. All types of study designs published in the English language were included. Studies that did not mention any barrier or facilitator, did not differentiate OPAT and inpatient, focused on specific antimicrobials or diseases, and made no distinction between parenteral and other treatments were excluded. Qualitative analysis was performed using the 'best-fit' framework approach and the Consolidated Framework for Implementation Research (CFIR). The review was PROSPERO registered (CRD42023441083). A total of 8761 studies were screened for eligibility and 147 studies were included. Problems in patient selection, lack of awareness, poor communication and co-ordination, lack of support, lack of structured service and inappropriate prescriptions were identified. OPAT provides safe, effective and efficient treatment while maintaining patients' privacy and comfort, resulting in less daily life disruption, and reducing the risk of infection. Satisfaction and preference for OPAT were very high. Initiatives in strengthening OPAT such as antimicrobial stewardship and telemedicine are beneficial. Challenges to and facilitators of OPAT were identified among patients, health professionals, OPAT service providers and healthcare administrators. Understanding them is crucial to designing targeted initiatives for successful OPAT service implementation.

Exploring patients' perspectives: a mixed methods study on Outpatient Parenteral Antimicrobial Therapy (OPAT) experiences

BACKGROUND

Outpatient Parenteral Antimicrobial Therapy (OPAT), an alternative to inpatient intravenous antibiotic therapy, has shown benefits in international studies such as increased patient satisfaction. Because OPAT has been used only sporadically in Germany so far, no structured results on patients' experiences and concerns regarding OPAT have yet been available. This study therefore aims to explore the experiences of OPAT patients in a pilot region in Germany.

METHODS

This is an observational study in a German pilot region, including a survey of 58 patients on their experiences with OPAT, and in-depth interviews with 12 patients (explanatory-sequential mixed-methods design).

RESULTS

Patients reported that they were satisfied with OPAT. That a hospital discharge was possible and anti-infective therapy could be continued in the home environment was rated as being particularly positive. In the beginning, many patients in the interviews were unsure about being able to administer the antibiotic therapy at home on their own. However, healthcare providers (doctors and pharmacy service provider staff) were able to allay these concerns. Patients appreciated regular contact with care providers. There were suggestions for improvement, particularly concerning the organization of the weekly check-up appointments and the provision of information about OPAT.

CONCLUSIONS

Patients were generally satisfied with OPAT. However, the treatment structures in Germany still need to be expanded to ensure comprehensive and high-quality OPAT care.

TRIAL REGISTRATION

NCT04002453, https://www.

CLINICALTRIALS

gov/ , (registration date: 2019-06-21).

Cost evaluation of a nurse coordinated outpatient parenteral antimicrobial therapy (OPAT) program

A structured, nurse-driven outpatient parenteral antimicrobial therapy (OPAT) program within an academic healthcare system was associated with reduced odds of 60-day unplanned OPAT readmissions and costs after hospital discharge. These findings may facilitate justifying additional resources for OPAT programs to improve care while decreasing costs.

Choosing patients over placebos: oral transitional therapy vs. IV-only therapy for bacteraemia and infective endocarditis

BACKGROUND

The belief that antibiotics must be administered intravenously (IV) to treat bacteraemia and endocarditis has its origins 70 years ago and has engrained itself in the psyche of the medical community and the public at large. This has led to hesitancy in adopting evidence-based strategies utilizing oral transitional therapy for the treatment of these infections. We aim to reframe the narrative around this debate, focusing on patient safety over vestigial psychology.

OBJECTIVES

This narrative review summarizes the current state of the literature regarding the use of oral transitional therapy for the treatment of bacteraemia and infective endocarditis, focusing on studies comparing it to the traditional, IV-only approach.

SOURCES

Relevant studies and abstracts from PubMed reviewed in April 2023.

CONTENT

Treating bacteraemia with oral transitional therapy has been studied in 9 randomized controlled trials (RCTs), totalling 625 patients, as well as numerous large, retrospective cohorts, including 3 published in the last 5 years alone, totalling 4763 patients. We identified 3 large, retrospective cohort studies; one quasi-experimental, pre-post study, and 3 RCTs of patients with endocarditis, totalling 748 patients in the retrospective cohorts and 815 patients in prospective, controlled studies. In all these studies, no worse outcomes were observed in the oral transitional therapy arm as compared with IV-only therapy. The main difference has consistently been longer durations of inpatient hospitalization and increased risk of catheter-related adverse events like venous thrombosis and line-associated blood stream infections in the IV-only groups.

IMPLICATIONS

There are ample data showing that choosing oral therapy reduces hospital stay and has fewer adverse events for patients than IV-only therapy, all with similar or better outcomes. In selected patients, choosing IV-only therapy may serve more as an anxiolytic "placebo" for the patient and provider rather than a necessity for treating the actual infection.

We'll take it from here: Veterans Affairs OPAT management of home IV therapy initiated at community hospitals

An outpatient parenteral antimicrobial therapy team from a Veterans Affairs facility managed patients discharged from their own facility and neighboring community hospitals. There were no significant differences in adverse outcomes between the groups, but a majority of regimens were modified from those initially proposed by community providers.

Physician Financial Incentives for Use of Outpatient Intravenous Antimicrobial Therapy: An Interrupted Time Series Analysis

BACKGROUND

In 2011, policymakers in British Columbia introduced a fee-for-service payment to incentivize infectious diseases physicians to supervise outpatient parenteral antimicrobial therapy (OPAT). Whether this policy increased use of OPAT remains uncertain.

METHODS

We conducted a retrospective cohort study using population-based administrative data over a 14-year period (2004-2018). We focused on infections that required intravenous antimicrobials for ≥10 days (eg, osteomyelitis, joint infection, endocarditis) and used the monthly proportion of index hospitalizations with a length of stay shorter than the guideline-recommended "usual duration of intravenous antimicrobials" (LOS < UDIVA) as a surrogate for population-level OPAT use. We used interrupted time series analysis to determine whether policy introduction increased the proportion of hospitalizations with LOS < UDIVA.

RESULTS

We identified 18 513 eligible hospitalizations. In the pre-policy period, 82.3% of hospitalizations exhibited LOS < UDIVA. Introduction of the incentive was not associated with a change in the proportion of hospitalizations with LOS < UDIVA, suggesting that the policy intervention did not increase OPAT use (step change, -0.06%; 95% confidence interval [CI], -2.69% to 2.58%; P = .97 and slope change, -0.001% per month; 95% CI, -.056% to .055%; P = .98).

CONCLUSIONS

The introduction of a financial incentive for physicians did not appear to increase OPAT use. Policymakers should consider modifying the incentive design or addressing organizational barriers to expanded OPAT use.

First-Dose Antimicrobial Infusion Reactions in Patients Enrolled in Outpatient Parenteral Antimicrobial Therapy Services

After receiving a monitored first-dose antimicrobial infusion at an infusion center, 6 of 93 (6%) patients enrolled in outpatient parenteral antimicrobial therapy services experienced an immediate reaction, none of which were consistent with immunoglobulin E-mediated reactions. These findings suggest it would be reasonable to forgo monitoring for most patients receiving first-dose intravenous antimicrobials outpatient.

A Bundle of the Top 10 OPAT Publications in 2022

Outpatient parenteral antimicrobial therapy (OPAT) has become more common in clinical settings. Correspondingly, OPAT-related publications have also increased; the objective of this article was to summarize clinically meaningful OPAT-related publications in 2022. Seventy-five articles were initially identified, with 54 being scored. The top 20 OPAT articles published in 2022 were reviewed by a group of multidisciplinary OPAT clinicians. This article provides a summary of the "top 10" OPAT publications of 2022.

Usefulness of Routine Laboratory Tests for Follow up of Patients Receiving Outpatient Parenteral Antimicrobial Therapy Run by Infectious Diseases Fellows

BACKGROUND

The infectious disease society of America (IDSA) recommends routine laboratory tests for all patients receiving outpatient parenteral antimicrobial therapy (OPAT) to monitor for adverse events. There are no data to support how often patients should take monitoring laboratory tests. In addition, the relevance of different laboratory tests commonly used for OPAT follow up is not clearly known.

METHODS

We conducted a retrospective observational cohort study over a 7-year study interval (1 January 2014 to 31 December 2021). Clinical data were obtained to identify the risk factors associated with abnormal laboratory tests and determine if abnormal laboratory tests led to antibiotic change or hospital readmission.

RESULTS

Two hundred and forty-six patients met the inclusion criteria for this study. In our multivariate analysis, the Charlson comorbidity index (CCI) of 0-4 (aOR 0.39, 95%Cl 0.18-0.86), the use of ceftriaxone without vancomycin (aOR 0.47, 95%Cl 0.24-0.91) and an OPAT duration of 2-4 weeks (aOR 0.47, 95%Cl 0.24-0.91) were associated with a lower risk of OPAT complications. A CCI of 5 or more (aOR 2.5, 95%Cl (1.1-5.7)) and an OPAT duration of 5 or more weeks (aOR 2.7, 95% Cl 1.3-5.6) were associated with a higher risk of OPAT complications. An abnormal complete metabolic panel or vancomycin levels, but not an abnormal complete blood count, were associated with antibiotic change or readmission.

CONCLUSION

Patients with fewer comorbidities, ceftriaxone and short OPAT durations are at lower risk for OPAT complications. These patients could be followed with less frequent laboratory monitoring.

Conventional Hospitalization versus Sequential Outpatient Parenteral Antibiotic Therapy for Staphylococcus aureus Bacteremia: Post-Hoc Analysis of a Multicenter Observational Cohort

It is not known whether sequential outpatient parenteral antimicrobial (OPAT) is as safe and effective as conventional hospitalization in patients with S. aureus bacteremia (SAB). A post-hoc analysis of the comparative effectiveness of conventional hospitalization versus sequential OPAT was performed in two prospective Spanish cohorts of patients with S. aureus bacteremia. The PROBAC cohort is a national, multicenter, prospective observational cohort of patients diagnosed in 22 Spanish hospitals between October 2016 and March 2017. The DOMUS OPAT cohort is a prospective observational cohort including patients from two university hospitals in Seville, Spain from 2012 to 2021. Multivariate regression was performed, including a propensity score (PS) for receiving OPAT, stratified analysis according to PS quartiles, and matched pair analyses based on PS. Four hundred and thirteen patients were included in the analysis: 150 in sequential OPAT and 263 in the full hospitalization therapy group. In multivariate analysis, including PS and center effect as covariates, 60-day treatment failure was lower in the OPAT group than in the full hospitalization group (p < 0.001; OR 0.275, 95%CI 0.129−0.584). In the PS-based matched analyses, sequential treatment under OPAT was not associated with higher 60-day treatment failure (p = 0.253; adjusted OR 0.660; % CI 0.324−1.345). OPAT is a safe and effective alternative to conventional in-patient therapy for completion of treatment in well-selected patients with SAB, mainly those associated with a low-risk source and without end-stage kidney disease.