Abstract
Background:
Outpatient Parenteral Antimicrobial Therapy (OPAT) is considered a patient-friendly and cost-effective practice. Patients in the OPAT service can be at risk for developing adverse events. Due to extensive variations in practice, guidelines have been developed to minimize the risks.
Objectives:
In this first worldwide survey on OPAT, we explored the current OPAT services around the world, adherence to recommendations and identified best practices and challenges from different perspectives.
Methods:
An e-survey was conducted and consisted of questions about demographics, characteristics of the OPAT service, role of pharmacy, future developments, and respondents’ views on improvements as well as best practices.
Results:
A total of 126 responses from 28 countries were included. Seventy-eight percent (78%) of the respondents stated that their facility provides antimicrobial therapy in the outpatient setting, whereas 22% did not. Forty-two percent (42%) of the hospitals with OPAT services had a specialized OPAT service, while 14% lacked specialized services and 22% had a partially specialized team in place. In facilities with a specialized OPAT service, the number of mandatory infectious disease (ID) consultations before discharge and clinical monitoring by an ID specialist or OPAT team member, the frequency of monitoring, and the availability of an OPAT registry were higher. A multidisciplinary team’s presence was commonly noted as best practices. On the other hand, respondents experienced difficulties with reimbursement and lack of standardization in the screening, follow-up and monitoring of patients.
Conclusion:
This survey provides a better understanding of the implementation and practices of OPAT services globally and describes best practices and the challenges from different professionals.
Plain language summary
Background
Outpatient parenteral antimicrobial therapy (OPAT) is defined as ‘the administration of parenteral antimicrobial therapy in at least 2 doses on different days without intervening hospitalization’ National and continental studies show a great proportion of unregulated OPAT services with the implementation of a specialized OPAT team varying extensively. Besides the perspectives of infectious disease specialists, the perspectives of other healthcare workers involved with OPAT is under investigated.
Method
An electronic e-survey was conducted with questions about demographics, characteristics of OPAT service, the role of the pharmacy in OPAT, future developments and best-practices and challenges
Results
OPAT services have a high global adoption rate of 78%, however only 42% of healthcare facilities offer formal OPAT services Facilities with formal OPAT services have higher requirements for infectious disease consultation before discharge, clinical monitoring by an OPAT team member, monitoring frequency, and availability of an OPAT registry Best practices include a multidisciplinary OPAT team and the use of elastomer pumps Common challenges in OPAT involve reimbursement issues and lack of standardization in patient screening, follow-up, and monitoring.
Conclusion
This is the first worldwide study exploring the implementation of OPAT services and perspectives of different professionals.
Keywords
Introduction
Outpatient parenteral antimicrobial therapy (OPAT) is defined as ‘the administration of parenteral antimicrobial therapy in at least 2 doses on different days without intervening hospitalization’. 1 It can be provided for patients who need parenteral therapy for severe or deep-seated infections, under the condition that they are stable and healthy enough to leave the hospital. 2 Currently, OPAT is considered part of regular care in many countries across Europe, Asia, North America, and Oceania. It is a safe, effective, and cost-saving practice.3 –9 Additionally, it reduces hospital-related complications due to shorter lengths of hospitalization, allows patients to regain autonomy, and ultimately leads to a better quality of life.3,10
Even though OPAT services are usually considered safe, patients receiving antimicrobials in an outpatient setting can still be at risk for readmission, due to adverse effects, line-related complications, and treatment failures.10,11 As OPAT can be performed in a variety of models, such as hospital in the home (HITH), hospital-based infusion centers, office-based infusion centers, and skilled nursing facilities, leading to variations in practice, guidelines have been developed to minimize those risks associated with OPAT.1,12,13 For this, a well-functioning and specialized OPAT program should be available, with a designated and multidisciplinary team that provides input on the choice, dose, and duration of therapy.12,14 By performing routine clinical and laboratory monitoring, efficacy can be both ensured and toxicities can be assessed and prevented. 1
The literature suggests that OPAT programs may deviate from the guidelines and recommendations.8,14,15 –21 Data from Europe and The United States of America indicate that, despite offering OPAT services, only one-third of the services have a formal OPAT program in place.15,17 This aligns with a few international surveys showing that there is a great proportion of unregulated OPAT services.14,19 The limitation of these studies is that they were performed from infectious disease (ID) specialists’ perspectives only, thereby potentially neglecting the multidisciplinary approach of the specialized OPAT program.15 –19 Moreover, best practices on how to organize OPAT services have not been studied yet. Therefore, a unique worldwide survey was conducted on the implementation and characteristics of OPAT services. This is the first study that aimed to explore the extent to which and in what way OPAT services have been implemented in countries throughout the world and to share respondents’ best practices, innovative ideas, and perspectives of different professions.
Methods
A prospective e-survey (using
One of the key introductory questions of the survey was whether a facility offered outpatient intravenous (IV) antimicrobial courses (regardless of the OPAT model in place). Respondents who did offer these treatments were asked detailed questions regarding their OPAT service, what respondents were least satisfied about in their OPAT services and any best practices or innovative ideas. In addition, pharmacists were asked about their role in OPAT services. On the other hand, respondents with facilities that did not offer such services were asked questions about reasons for not having an OPAT service and future directions instead.
Data analysis
After closing the survey, data were extracted from LimeSurvey® (LimeSurvey GmbH, Hamburg). Responses were included when at least the following obligatory questions were answered: ‘what is your profession?’ and ‘does your facility/hospital/clinic provide outpatient (intravenous) IV antimicrobial courses?’ Incomplete responses were only included if the mandatory questions had been answered. Duplicate responses were excluded, except for duplicates from the same hospital but from different professions, as differences in perspectives can yield different answers. For further analysis, SPSS version 28.0.1.0 (IBM Corp. Armonk, NY) was used. Descriptive data analysis was conducted, whereby frequencies and percentages were calculated for each available survey question. Both completed and partially completed questionnaires were analyzed using the number of completed responses per item as the denominator. If a question was left unanswered, it was considered a missing value and included in the analysis as ‘unanswered’. The qualitative responses from the open-ended questions were used to illustrate the respondents’ experiences and perspectives.
Results
The survey yielded 126 responses originating from 103 facilities and 28 countries. The demographics of the survey respondents are shown in Table 1. The respondents were from Europe [
Demographics of survey respondents.
Other includes: regional (
Other includes: secondary hospital (
Primary disciplines of (specialist) nurse include IDs (
Primary disciplines of physicians include internal medicine (
Other includes: hospital pharmacist (
IDs, infectious diseases.

Countries represented by respondents: Argentina (
Characteristics of OPAT services.
Other includes: patient home, hospital-based clinic, and rehabilitation center (
Other includes: self-administration if the patient is capable. If not, then a nurse (
Other includes: (clinical) pharmacist (
Other includes: biweekly (
Other includes: clinical biologist (
OPAT registry or database was used for track service utilization (
Multiple answers were allowed.
OPAT, outpatient antimicrobial therapy; ID, infectious disease; TDM, therapeutic drug monitoring.
For those offering OPAT services, 41/98 (42%) had a specialized and designated OPAT team in place, while 14/98 (14%) lacked specialized services, and 22/98 (22%) indicated to have a partially specialized OPAT team (see Table 2). In Australia and Europe, the majority (84% and 69% respectively) had specialized or partially specialized OPAT services in place. Facilities with a partially specialized OPAT team revealed that they approached the services differently. For example, by dividing tasks among professionals or having the transmural or the antibiotic stewardship team in charge of the OPAT service.
Facilities with a specialized OPAT service indicated the following professions as part of their OPAT staff: 33/41 (81%) pharmacists, 32/41 (78%) ID specialists, 28/41 (68%) specialized nurses, and 15/41 (37%) microbiologists. Social workers (

Comparison of overall response and response from facilities with specialized OPAT services with a designated team.
7/28 (25%) of the facilities with no OPAT services stated that the reason of absence of an OPAT service was that it was improbable that resources would be set aside to develop this type of service, and 5/28 (18%) answered there was not enough time to discuss it. Other reasons were lack of expertise, the misuse by drug abusers, lack of reimbursement from health insurance, and laboratory monitoring. In facilities with no OPAT services, 5/28 (18%) were convinced they would not launch an OPAT service, 5/28 (18%) wanted to develop it in more than a year’s time, and 13/28 (46%) were not sure about it. While 8/28 (29%) would not refer a patient for treatment if a local and effective OPAT service was available, the majority – 15/28 (54%) – would.
Role of professionals in OPAT services
Pharmacists staffed the specialized OPAT team most frequently. The role of the pharmacy/pharmacist in OPAT in 36/63 (57%) of cases was advising dosages based on TDM results, followed by 29/63 (46%) drug preparation, and in 29/63 (46%) cases also the central oversight of procedures. There were several other functions appointed by the respondents. Pharmacists were involved, among others, in screening patients for OPAT, informing patients and healthcare members, and reviewing prescriptions. In addition, the pharmacist in OPAT services may have to deal with purchasing drugs and equipment and delivering them to the patient. It was further mentioned that pharmacists could also arrange funding and discuss prices with third parties.
Best practices and innovative ideas
One of the most common best practices and/or innovative ideas was having a multidisciplinary team as an advisory body and/or executor of OPAT. However, the tasks and responsibilities of such a team differed. Some respondents stated that this team provided input and advice concerning OPAT, while others indicated that there was mandatory prior consent by the team to start OPAT, and some stated even a more extensive role in the follow-up and monitoring of the patients by the same team. If it was not a multidisciplinary team, it could be an ID specialist responsible for advice and evaluation before discharge and/or overall responsibility for OPAT patients. In contrast, a specialized nurse team was also mentioned several times as a best practice, responsible for all or part of clinical evaluation, administration of the drug at home, or coordination of the OPAT services.
Another common best practice mentioned was the use of elastomeric pumps. A related suggestion was to alter the antimicrobial treatment regimen to continuous infusions to fit the HITH model and that research to further exploit this should be conducted. In addition, it was suggested that by investigating the stability of antimicrobials the number of antibiotics in OPAT can be expanded. One of the respondents mentioned that they were already carrying out stability studies.
To ensure the quality of OPAT practices, good cooperation and communication between the different stakeholders were mentioned. For example, by establishing protocols from the hospital for home nursing, or accessibility of the electronic patient dossier. The benefits of an OPAT registry, accessible to all parties involved, were addressed.
Other practices were more patient centered. One hospital mentioned using laminated sheets with instructions to educate their patients in S-OPAT. Another hospital was developing an app for patients to allow for better communication.
Challenges of OPAT
One of the leading challenges that emerged from the survey was related to costs and reimbursement. A few hospitals mentioned that there were no additional finances to further expand the OPAT services and realize innovative ideas. Others highlighted the fact that patients had to compensate for the cost and this could lead physicians to choose the antibiotic with the lowest cost, but not necessarily the most narrow-spectrum antibiotic.
A frequently mentioned challenge was the screening and follow-up of OPAT patients. It emerged that patient selection suitable for OPAT still needed to be further developed or standardized. In some cases, it was only at the request of the treating physician. There was also no standardization of patient follow-up. A designated and/or multidisciplinary team responsible for all components of OPAT was missed by some respondents. The availability and logistics of TDM was mentioned several times as a challenge. It was one of the reasons, besides drug stability and dosing regimen, for the limited number of antimicrobials used in OPAT services.
In other cases, facilities indicated that transparency and communication between different healthcare professions could be pitfalls. In addition, it took considerable time when multiple professionals were involved to get procedures going. Following this, bureaucracy was also time-consuming. Others indicated there was a need for database support and digitalization. Furthermore, difficulties were encountered regarding the organization of OPAT. Overall, not having a standard in-house procedure, the nonavailability of round-the-clock services, lack of staff, and high workload were mentioned frequently as challenges.
Discussion
The results of this unique global study showed a widespread adoption of OPAT worldwide (78%). This is in line with previous national or continental studies.8,16,17,20,22 The implementation of a specialized OPAT team however varied extensively, with only 41/98 (42%) of the respondents providing OPAT services with a designated team. This latter finding is in line with other studies.8,15
–17,20 A study from Europe by Emilie
The Infectious Diseases Society of America (IDSA) guideline describes that an ID specialist should address all medical decisions and have the final responsibility for patient care. 1 Previous studies showed that mandatory ID specialist consultations prior to discharge, follow-up appointment tracking, and laboratory tracking are significantly higher in formal OPAT programs compared to facilities with no formal OPAT programs, addressing the importance of a dedicated OPAT service.8,19 This is reflected in the results of our study. We found that it is more likely that a mandatory ID specialist consultation took place prior to discharge at facilities with a designated OPAT team, as well as monitoring performed by an OPAT clinician/team member, and an expert in IDs. Taking this into account, together with a higher frequency of monitoring and higher availability of an OPAT database seen in formal OPAT program, this study shows that a formal OPAT program in place leads to a higher adherence to the OPAT guidelines. Furthermore, having a formal OPAT program in place can tackle the frequently cited challenge of standardizing the screening and follow-up of OPAT patients.
IDSA guidelines and other guidelines recommend having a pharmacist, ID specialist, and (specialist) nurse on the OPAT team.1,9,12,13 This study found that in 80% of the facilities with a designated OPAT team a pharmacist was part of the team. The ID specialist and (specialist) nurses were part of the OPAT team in 78% and 68% of the cases, respectively. In this study we found that one of the main responsibilities of a pharmacist in OPAT was giving TDM advice, followed by drug preparation, and the central oversight of procedures. A recent survey on the role of pharmacists on OPAT revealed that pharmacists gave a lot of value to selecting the initial antimicrobial regimen and reviewing patients for OPAT appropriateness. 23 Given the knowledge of pharmacists, it would be well to also include them in these areas of OPAT.
Frequently named best practices were having a multidisciplinary OPAT team in place or specialist nurses responsible for all or part of the OPAT care and the use of elastomeric pumps. A need for expanding the antimicrobial assortment in OPAT was mentioned several times. We hypothesize that the stability of antimicrobials due to differences in climates and temperatures may limit the implementation of antimicrobials used in OPAT. Costs and timing issues were two common OPAT challenges. These two are also crucial factors that have an impact on the decisions made in healthcare overall, and important reasons for implementing OPAT in the first place. Indeed, the absence of OPAT among the respondents was also mostly due to the lack of resources and time. These challenges are recognizable from previous research.8,14 A different approach to OPAT services may be an option to initiate OPAT, as some facilities from this survey did, by, for example, dividing the tasks of OPAT among different professionals or having the ID specialist or the antibiotic stewardship team responsible for OPAT. Interestingly, 29% of the respondents would not refer a patient for treatment if a local and effective OPAT service was available, even though the reason for this was not asked in the survey. Although this was not questioned, we hypothesize that it might be due to reimbursement issues.
One of the main limitations of this study is that a large number of the responses originated from Europe, particularly Belgium. This makes it debatable if this report accurately depicts OPAT management around the globe; however, upon examination, the data from Belgium are comparable to the rest of Europe, so we expect that the overall data are not affected greatly. Even though the majority of the responses originated from Europe, we also collected data for continents with no readily available data in the literature. Furthermore, there is a possibility of nonresponse bias as a result of partially completed responses. This may be explained due to the majority of the questions in the survey not being mandatory and answer option ‘unsure’ was allowed. However, it may have led to a more accessible survey and an increase in the number of respondents as professionals with limited knowledge on some parts of their OPAT service could participate. By allowing free text, the quantitative data was affected. However, an attempt was made to create in-depth answers by giving respondents the opportunity to deviate from the multiple-choice options and fill in an answer themselves. Another cause for biased results can be a reduced participation of facilities that do not provide OPAT services. These facilities may have found it unnecessary to participate in the study.
To the best of our knowledge, this is the first study that examined the global implementation of OPAT services from the perspective of different professions, including pharmacists (66% of the respondents). In this way, different perspectives on best practices and challenges could be identified. Important to note is that this study made a distinction between an OPAT service that is fully specialized and one that is partially specialized. In that way, the study was able to identify cases that take a different approach and give a good reflection of real-time practices. By examining both current and long-term goals, an effort has been made to paint a complete picture of the services. The results have shown best practices and innovative ideas that highlight some of the recommendations by guidelines, for instance, having a specialized OPAT team. However, there is still a lot of room for improvement regarding the implementation of OPAT and the pursuit of national and international guidelines. The findings of this study demonstrated that OPAT implementation varied significantly. Future research can generate more data regarding OPAT methods to standardize OPAT.
In conclusion, this study has mapped the implementation and practices of OPAT around the world and provides a unique perspective on best practices and challenges from different professionals involved in OPAT. Additionally, it can offer directions for institutions that want to launch an OPAT service or further develop their current OPAT service.
Supplemental Material
sj-docx-1-tai-10.1177_20499361231214901 – Supplemental material for Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers
Supplemental material, sj-docx-1-tai-10.1177_20499361231214901 for Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers by Moska Hassanzai, Fadime Adanç, Birgit C P Koch, Nelianne J Verkaik, Jakob van Oldenrijk, Jorg L de Bruin, Brenda C M de Winter and Hein A W van Onzenoort in Therapeutic Advances in Infectious Disease
Supplemental Material
sj-docx-2-tai-10.1177_20499361231214901 – Supplemental material for Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers
Supplemental material, sj-docx-2-tai-10.1177_20499361231214901 for Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers by Moska Hassanzai, Fadime Adanç, Birgit C P Koch, Nelianne J Verkaik, Jakob van Oldenrijk, Jorg L de Bruin, Brenda C M de Winter and Hein A W van Onzenoort in Therapeutic Advances in Infectious Disease
Supplemental Material
sj-docx-3-tai-10.1177_20499361231214901 – Supplemental material for Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers
Supplemental material, sj-docx-3-tai-10.1177_20499361231214901 for Best practices, implementation and challenges of outpatient parenteral antimicrobial therapy: results of a worldwide survey among healthcare providers by Moska Hassanzai, Fadime Adanç, Birgit C P Koch, Nelianne J Verkaik, Jakob van Oldenrijk, Jorg L de Bruin, Brenda C M de Winter and Hein A W van Onzenoort in Therapeutic Advances in Infectious Disease
Footnotes
References
Supplementary Material
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