Prescription Support System for Antimicrobial Use in Belgian Primary Care (PaSSo)

Impact Evaluation of a Prescription Search Support (PSS) for Antimicrobials Using a Stepped-Wedge Cluster Randomized Design in Belgian Primary Care

Inappropriate antibiotic prescribing in primary care remains an important contributor to antimicrobial resistance. Despite the availability of evidence-based clinical guidelines, antibiotics are still frequently prescribed for self-limiting infections. Digital clinical decision support tools may help general practitioners (GPs) align prescribing decisions with guideline recommendations during patient consultations.

This study evaluates the impact of a digital Prescription Support System (PSS) designed to support antimicrobial prescribing in Belgian primary care. The PSS provides guideline-based recommendations derived from the Belgian BAPCOC guidelines for common infections in ambulatory care. Recommendations are presented through a user-friendly decision tree that is integrated into existing electronic health record systems and can be consulted during routine care.

The study is embedded within the national implementation strategy of the PSS coordinated by the National Institute for Health and Disability Insurance (RIZIV-INAMI). A stepped-wedge cluster randomized design is used, in which participating general practices transition sequentially from usual care to access to the PSS over four predefined implementation steps. This approach ensures that all participating practices eventually receive access to the system while allowing comparisons over time.

The primary objective is to assess whether implementation of the PSS is associated with changes in antibiotic prescribing in Belgian general practice. Prescribing outcomes are measured using routinely collected indicators from the Belgian Antibiotic Barometer, including overall antibiotic prescribing rates and the use of broad- versus narrow-spectrum antibiotics. Secondary objectives include assessing the usability and acceptability of the PSS among clinicians and identifying factors that influence its adoption in daily practice. The study will also monitor potential unintended consequences, such as changes in workflow or concerns about underprescribing.

Findings from this study will inform future decisions regarding further optimization and wider implementation of the PSS in Belgian primary care.

Study Overview

• Status: Recruiting
• Conditions: Infectious Diseases
• Intervention / Treatment: Other: Prescription Support System (PSS)

Detailed Description

Inappropriate antibiotic prescribing in primary care contributes to the development of antimicrobial resistance. Despite guidelines and public health efforts, overprescribing remains prevalent, especially for self-limiting infections which often resolve without antibiotic treatment. Digital tools such as a Prescription Search Support (PSS) may aid general practitioners (GPs) in making more informed prescribing decisions.

This implementation project builds upon a previously conducted mixed-methods implementation study evaluating the usability of a PSS, which was approved by the Ethical Review Board UZ KU Leuven (Onderwijs-Begeleidingscommissie) on 27 September 2024 (MP031770).

The PSS under study contains the current recommendations for the proper use of antimicrobial agents for common infections in ambulatory care in Belgium. In other words, it represents the BAPCOC guidelines in a digital and user-friendly environment, by using a decision tree. Advice for the following diagnoses (ICPC-2 codes) is included in the PSS: sore throat (R21, R74), pertussis (R71), common cold (R74), acute rhinosinusitis (R75), acute bronchitis / bronchiolitis (R78), influenza (R80), pneumonia (R81), ear pain (H01), otorrhea (H04), acute otitis media (H71), acute epiglottitis (R77), acute exacerbations of chronic obstructive pulmonary disease, aspiration pneumonia (R81), laryngitis stridulosa (R77), acute cystitis (U71), acute prostatitis (Y73), acute pyelonephritis (U70), acute vulvovaginitis (X84), asymptomatic bacteriuria, epididymo-orchitis (Y74), genital herpes (Y72, X90), partner treatment and treatment of asymptomatic sexually transmitted infections, pelvic inflammatory disease (X74), syphilis (X70, Y70), and urethritis (U72).

This PSS was developed as part of the Belgian National Action Plan on AMR by the Federal Public Service Health, Food Chain Safety and Environment and the National Institute for Health and Disability Insurance (NIHDI; RIZIV-INAMI), in collaboration with various experts and stakeholders, including physicians, infectiologists, hygienists, policymakers, guideline developers, and software developers. The company Smals, under instruction of RIZIV-INAMI, developed the software for this application in close collaboration with the RIZIV-INAMI working group. Guideline recommendations regarding appropriate prescribing of antimicrobials in ambulatory care were converted into decision rules, which serve as the knowledge source for the PSS.

Digital education offers several advantages, such as easy access without time or location constraints, varying possible forms and levels, and the ability to disseminate evidence on a large scale. Previous research has shown that standalone web- or smartphone-based applications in this context have the potential to increase physicians' knowledge of antimicrobials and guideline recommendations, potentially improving guideline adherence.

In Belgium, antibiotic use in ambulatory care is closely monitored through the Antibiotic Barometer, a national surveillance system coordinated by the Academic Centre of General Practice of KU Leuven and financed by the National Institute for Health and Disability Insurance (RIZIV-INAMI). The Antibiotic Barometer was approved by the Sociaal-maatschappelijke Ethische Commissie (SMEC; G-2023-6352) and provides quarterly feedback to general practices based on routine health insurance claims data.

This study evaluates the implementation and impact of the PSS in routine Belgian primary care using a stepped-wedge cluster randomized trial design. Participating general practices are recruited to ensure broad representation across Belgian primary care. General practices constitute the unit of randomization and are randomly allocated to one of four predefined implementation steps. All practices start in a control condition without access to the PSS and transition once to the intervention condition according to their assigned step. Each implementation step lasts three months, after which practices retain access to the PSS for the remainder of the study period. By the end of the study, all participating practices will have received access to the intervention.

Data for this study are derived from routine sources and handled within the secure data infrastructure of KU Leuven. Prescribing data obtained via the Antibiotic Barometer are aggregated and pseudonymized at practice level prior to analysis, ensuring that individual patients cannot be identified. Data linkage, storage, and analysis are conducted in accordance with applicable data protection regulations. Quantitative and qualitative analyses are used to evaluate both the effectiveness and implementation of the PSS in real-world primary care. Findings from this study will inform future policy decisions regarding national rollout, optimization, and long-term integration of the PSS within Belgian antimicrobial stewardship strategies.

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Vlaams-Brabant
    • Leuven, Vlaams-Brabant, Belgium, 3000
      • Recruiting
      • GPs associated with KU Leuven
      • Contact: Hannelore Dillen, PhD; Phone Number: +32498828605; Email: hannelore.dillen@kuleuven.be
      • Contact: Annelien Dankaerts, MD; Email: annelien.dankaerts@kuleuven.be
      • Principal Investigator: Jan Y Verbakel, MD, PhD, professor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• General practices in Belgium using compatible EHR systems.
• Willingness to use and activate the PSS by giving consent.
• Agreement to participate in the study, provided signed informed consent form is in place.

Exclusion Criteria:

• Practices using an EHR system that solely allows a single sign-on to the standalone PSS.
• Practices already using a similar PSS or participating in overlapping projects.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control: Usual Care; In the control arm, general practices will provide usual care, left at the discretion of the treating general practitioner. Apart from the general information or training session attended by all participating physicians prior to recruitment and randomization, practices in the control arm will not receive access to the Prescription Support System (PSS) or any additional decision support tools. General practitioners in the control arm are expected (but not forced) to follow the Belgian guidelines for antimicrobial prescribing, as described in the BAPCOC national guidelines.
Active Comparator: Intervention: access to PSS; Prescription Support System (PSS) Providing guideline-based recommendations for antimicrobial prescribing in ambulatory care.	Other: Prescription Support System (PSS); General practices in this arm have access to the Prescription Support System (PSS), a digital clinical decision support tool integrated into the electronic health record that provides guideline-based recommendations for antimicrobial prescribing in ambulatory care. The PSS presents recommendations derived from the Belgian BAPCOC guidelines using a structured decision-tree format. During eligible consultations, the PSS can be consulted by the general practitioner to support clinical decision-making regarding antibiotic prescribing. The tool provides information on recommended antibiotic choice, dosage, and duration, as well as guidance on situations in which antibiotic treatment is not indicated. Practices transition to this arm according to the stepped-wedge design and retain access to the PSS for the duration of the study.; Other Names: Clinical decision support system (CDSS)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Antibiotic Prescribing Rate in General Practice	To evaluate whether the PSS reduces antibiotic prescribing rates in Belgian general practice. The project will assess whether implementation of the PSS tool leads to improvements in specific prescribing indicators as monitored by the Belgian Antibiotic Barometer (AB Barometer). These include total antibiotic prescribing rate and use of broad- versus narrow-spectrum antibiotics.	Measured quarterly from baseline until study completion (up to 12 months per practice).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intensity of PSS use	PSS usage intensity at practice level derived from application log files (e.g., frequency of access/consultations and categorization into high, medium, or no use during the intervention period), reflecting the overall level of exposure to the PSS.	Measured during the intervention period from each practice's transition to the PSS arm until study completion (up to 12 months).
Usability and acceptability of the PSS - clinician reported	To assess the usability of the Prescription Support System (PSS) among general practitioners in routine clinical practice. Usability will be explored through semi-structured interviews with clinicians. The evaluation will examine clinicians' experiences with the PSS, perceived usefulness, ease of use, and integration into workflow, and factors influencing adoption, sustained use, and perceived impact on prescribing decisions.	Assessed after transition to the intervention group, during the final 6 months of the study period.
Usability and acceptability of the PSS - system usage	Usability of the Prescription Support System (PSS) will also be assessed using system usage data derived from application log files, including patterns of use and interaction with the PSS during routine clinical practice, focusing on how the system is used rather than how often it is accessed.	Assessed during the intervention period from each practice's transition to the PSS arm until study completion (up to 12 months).
Potential Unintended Consequences of PSS Implementation - clinician reported	To monitor potential unintended consequences associated with implementation of the Prescription Support System (PSS), including perceived workflow disruption. These outcomes will be explored using qualitative information obtained through semi-structured interviews with clinicians.	Assessed after transition to the intervention group, during the final 6 months of the study period.
Potential Unintended Consequences of PSS Implementation - system usage	To monitor potential unintended consequences associated with implementation of the Prescription Support System (PSS), including signals of underprescribing and changes in prescribing patterns. These outcomes will be explored using routinely collected prescribing indicators from the Belgian Antibiotic Barometer.	Measured quarterly from baseline until study completion (up to 12 months)

Collaborators and Investigators

• Sponsor: KU Leuven
• Collaborators: National Institute for Health and Disability Insurance (RIZIV-INAMI); INTEGO - Flemish General Practice Morbidity Registry (KU Leuven); SMALS

Publications and helpful links

General Publications

• Madar R, Ugon A, Ivankovic D, Tsopra R. A Web Interface for Antibiotic Prescription Recommendations in Primary Care: User-Centered Design Approach. J Med Internet Res. 2021 Jun 11;23(6):e25741. doi: 10.2196/25741.
• Delory T, Jeanmougin P, Lariven S, Aubert JP, Peiffer-Smadja N, Boelle PY, Bouvet E, Lescure FX, Le Bel J. A computerized decision support system (CDSS) for antibiotic prescription in primary care-Antibioclic: implementation, adoption and sustainable use in the era of extended antimicrobial resistance. J Antimicrob Chemother. 2020 Aug 1;75(8):2353-2362. doi: 10.1093/jac/dkaa167.
• Helou RI, Foudraine DE, Catho G, Peyravi Latif A, Verkaik NJ, Verbon A. Use of stewardship smartphone applications by physicians and prescribing of antimicrobials in hospitals: A systematic review. PLoS One. 2020 Sep 29;15(9):e0239751. doi: 10.1371/journal.pone.0239751. eCollection 2020.
• Fralick M, Haj R, Hirpara D, Wong K, Muller M, Matukas L, Bartlett J, Leung E, Taggart L. Can a smartphone app improve medical trainees' knowledge of antibiotics? Int J Med Educ. 2017 Nov 30;8:416-420. doi: 10.5116/ijme.5a11.8422.
• Kyaw BM, Tudor Car L, van Galen LS, van Agtmael MA, Costelloe CE, Ajuebor O, Campbell J, Car J. Health Professions Digital Education on Antibiotic Management: Systematic Review and Meta-Analysis by the Digital Health Education Collaboration. J Med Internet Res. 2019 Sep 12;21(9):e14984. doi: 10.2196/14984.
• 1. BAPCOC - Belgische Gids voor Anti-Infectieuze Behandeling in de Ambulante Praktijk 2022. Available from: https://www.bcfi.be/nl/chapters/12?frag=8000010. Accessed 11 July 2024.

Study record dates

Study Major Dates

• Study Start (Actual): December 21, 2025
• Primary Completion (Estimated): December 21, 2026
• Study Completion (Estimated): March 31, 2027

Study Registration Dates

• First Submitted: December 23, 2025
• First Submitted That Met QC Criteria: January 8, 2026
• First Posted (Actual): January 16, 2026

Study Record Updates

• Last Update Posted (Actual): March 6, 2026
• Last Update Submitted That Met QC Criteria: March 5, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Clinical Decision Support; Primary Care; Antibiotics; Antimicrobial Stewardship; Stepped-Wedge Cluster Randomized Trial
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Infections; Pathological Conditions, Signs and Symptoms; Communicable Diseases
• Other Study ID Numbers: MP037810 (Other Identifier: KU Leuven - Educational Review Board (OBC))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual patient data from this trial will not be published in the public domain. Deidentified participant data is available for further analyses. Requests for data, with justification, should be sent to Jan Verbakel (jan.verbakel@kuleuven.be). The trial protocol is available online for an indefinite period.
• IPD Sharing Time Frame: Study protocol is published and accessible. SAP, CSR, ICF and analytical code will be available after publishing the results in a medical journal. Individual patient data from this trial will not be published in the public domain.
• IPD Sharing Access Criteria: Individual patient data from this trial will not be published in the public domain. Deidentified participant data is available for further analyses. Requests for data, with justification, should be sent to Jan Verbakel (jan.verbakel@kuleuven.be). The trial protocol is available online for an indefinite period.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No