The ImpProGUIDE study aims to find out whether implementing new Swiss national guidelines for acute respiratory infections (ARI) can help to reduce antibiotic prescribing in primary care. In Switzerland, most antibiotics are prescribed in outpatient care, and many of these prescriptions may not be needed - especially when infections are caused by viruses, which antibiotics do not treat. Reducing overuse of antibiotics is important to slow the spread of antibiotic resistance. The new guidelines were developed by the Swiss Society for Infectious Diseases (SSI) to support family doctors in managing ARIs, based on a syndromic approach. They recommend the targeted use of point-of-care C-reactive protein (CRP) testing when bacterial infection is suspected, as well as shared decision-making with patients. This study will be carried out in quality circles (QCs) - small groups of family doctors who meet regularly to discuss and improve clinical practice - and in walk-in clinics in French- and Italian-speaking regions of Switzerland. Each will be randomly assigned to either an "intervention" group or a "control" group. In the intervention group, QC moderators and medical center directors will receive implementation resources to lead a session and distribute materials to their group in autumn 2025 on the new guidelines. Doctors can then decide whether or not to use the recommendations in their consultations. In the control group, QCs and centers will continue their regular activities. They will receive access to the same educational materials later, in summer 2026. Throughout the study, the researchers will collect de-identified data from health insurance billing records to track antibiotic prescribing and the use of diagnostic tests. Doctors and QC moderators will also be invited to complete short online surveys twice a year (10-15 minutes) and may be asked to join optional interviews or group discussions after the winter season. The study will also explore the effectiveness of the implementation strategies on the adoption of the SSI guidelines, as well as the barriers and facilitators to adoption. This study type is known as a hybrid effectiveness implementation study, simultaneously evaluating an intervention's impact on antibiotic prescribing and the strategies used to implement the new national guidelines in a real-world setting. Participation in the study is voluntary. Doctors can withdraw at any time. All data will be handled confidentially and in line with Swiss data protection laws. The study is funded by the Swiss National Science Foundation. No support is received from pharmaceutical companies or manufacturers of diagnostic tests.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
200
Implementation strategies are deployed within quality circles, consisting of a structured educational session including a PowerPoint presentation, a facilitation guide, clinical vignettes, and printed materials for physicians and patients. The session is designed to support clinical decision-making about antibiotic use for ARI, based on targeted use of CRP and shared decision-making.
Unisanté
Lausanne, Canton of Vaud, Switzerland
RECRUITINGDefined daily doses of antibiotics commonly used for acute respiratory infections per 1000 consultations
Defined daily doses (DDD) of selected antibiotics (amoxicillin, co-amoxicillin, clarithromycin, azithromycin) per 1000 consultations, based on de-identified health insurance billing data. These antibiotics represent those most commonly prescribed for pneumonia, acute bronchitis, and upper respiratory tract infections (excluding pharyngitis, sinusitis, and otitis media).
Time frame: Over the influenza-like illness (ILI) season (6 months).
Penetration of acute respiratory infection guidelines
Percentage of physicians who self-declare adoption of the new acute respiratory infection (ARI) guidelines (i.e., treating patients according to the guidelines).
Time frame: Baseline and after 6 months.
Monthly antibiotic prescribing rate
Monthly prescribing rates expressed as: (1) DDD of antibiotics commonly used for ARI per 1000 consultations, and (2) DDD of total antibiotics per 1000 consultations.
Time frame: Monthly for 12 months.
Model-estimated differences in antibiotic use
Multilevel regression coefficients estimating differences in antibiotic use (DDD per 1000 consultations) according to physician, practice, quality circle (QC), walk-in clinic, and patient characteristics.
Time frame: Over the ILI season (6 months).
Model-estimated differences in antibiotic use
Multilevel regression coefficients estimating differences in antibiotic use (DDD per 1000 consultations) according to physician, practice, QC, walk-in clinic and patient characteristics.
Time frame: Over 12 months.
Use of diagnostic tests
Number of C-reactive protein (CRP) measurements, blood counts, and chest radiographs per 1000 consultations.
Time frame: Over the ILI season (6 months).
Perceived acceptability of the CRP flowchart
Perceived acceptability of the CRP flowchart, measured using a French translation of the "Acceptability of Intervention Measure" (5-point Likert scale, higher score means better outcome).
Time frame: Baseline and after 6 months.
Perceived acceptability of the CRP flowchart assessed by custom questions
Perceived acceptability of the CRP flowchart, assessed using study-specific custom questions (e.g. "I generally agree with prescribing antibiotics in patients with an acute respiratory infection and a CRP level ≥ 100 mg/L." (question originally asked in French), with answer options according to a 5-point Likert scale, higher scores indicate better outcomes).
Time frame: Baseline and after 6 months.
Perceived acceptability of shared decision-making
Perceived acceptability of shared decision-making, measured using a French translation of the "Acceptability of Intervention Measure" (5-point Likert scale, higher score means better outcome).
Time frame: Baseline and after 6 months.
Perceived acceptability of shared decision-making assessed by custom questions
Perceived acceptability of shared decision-making, assessed using study-specific custom questions (e.g. "I appreciate the Consultation Support Tool for shared decision-making." (question originally asked in French), with answer options according to a 5-point Likert scale; higher scores indicate better outcomes).
Time frame: Baseline and after 6 months.
Perceived appropriateness of the CRP flowchart
Perceived appropriateness of the CRP flowchart, measured using a French translation of "Intervention Appropriateness Measure" (5-point Likert scale, higher score means better outcome).
Time frame: Baseline and after 6 months.
Perceived appropriateness of the CRP flowchart assessed by custom questions
Perceived appropriateness of the CRP flowchart, assessed using study-specific custom questions (e.g. "The CRP decision tree corresponds to the patient population in my practice/medical center." (question originally asked in French), with answer options according to a 5-point Likert scale, higher scores indicate better outcomes).
Time frame: Baseline and after 6 months.
Perceived appropriateness of shared decision-making
Perceived appropriateness of shared decision-making, measured using a French translation of "Intervention Appropriateness Measure" (5-point Likert scale, higher score means better outcome).
Time frame: Baseline and after 6 months.
Perceived appropriateness of shared decision-making assessed by custom questions
Perceived appropriateness of shared decision-making, assessed using study-specific custom questions (e.g. "Shared decision-making in patients with an acute respiratory infection and a CRP level ≥ 50 mg/L and \< 100 mg/L corresponds to the patient population in my practice/medical center." (question originally asked in French), with answer options according to a 5-point Likert scale, higher scores indicate better outcomes).
Time frame: Baseline and after 6 months.
Perceived feasibility of the CRP flowchart
Perceived feasibility of the CRP flowchart, measured using a French translation of "Feasibility of Intervention Measure" (5-point Likert scale, higher score means better outcome).
Time frame: Baseline and after 6 months.
Perceived feasibility of the CRP flowchart assessed by custom questions
Perceived feasibility of the CRP flowchart, assessed using study-specific custom questions (e.g. "CRP testing in patients with an acute respiratory infection can be performed within a reasonable timeframe." (question originally asked in French), with answer options according to a 5-point Likert scale, higher scores indicate better outcomes).
Time frame: Baseline and after 6 months.
Perceived feasibility of shared decision-making
Perceived feasibility of shared decision-making, measured using a French translation of "Feasibility of Intervention Measure" (5-point Likert scale).
Time frame: Baseline and after 6 months.
Perceived feasibility of shared decision-making assessed by custom questions
Perceived feasibility of shared decision-making, assessed using study-specific custom questions (e.g. "Shared decision-making in patients with an acute respiratory infection and a CRP level ≥ 50 mg/L and \< 100 mg/L takes too much time." (question originally asked in French), with answer options according to a 5-point Likert scale, higher scores indicate better outcomes).
Time frame: Baseline and after 6 months.
Intended adoption of acute respiratory infection guidelines
Intended adoption of the new ARI guideline using custom questions. Intended adoption of the CRP flowchart using custom questions. Intended adoption of shared decision-making using custom questions.
Time frame: Baseline and after 6 months.
Fidelity to C-reactive protein
Fidelity to the CRP flowchart of the new ARI guidelines, using custom questions.
Time frame: Baseline and after 6 months.
Fidelity to shared decision-making
Fidelity to shared decision-making of the new ARI guidelines, using custom questions.
Time frame: Baseline and after 6 months.
Anticipated sustainment of acute repiratory infection guidelines
Anticipated sustainment of the new ARI guidelines, using custom questions.
Time frame: Baseline and after 6 months.
Intended adoption of implementation strategies
Intended adoption of implementation strategies, measured with custom questions (5-point Likert scale, higher score is higher intention to adopt).
Time frame: Baseline and after 6 months.
Adoption of implementation strategies
Adoption of implementation strategies, measured with custom questions (single answer, yes/no).
Time frame: Baseline and after 6 months.
Appropriateness of implementation strategies
Perceived appropriateness of implementation strategies delivered through and outside QCs, measured with custom questions (5-point Likert scale, higher score is higher appropriateness).
Time frame: Baseline and after 6 months.
Fidelity in delivering the implementation strategies
Fidelity of delivering the implementation strategies as intended, using custom questions.
Time frame: During the ILI season (6 months).
Acceptability of moderator implementation materials
Acceptability of implementation materials for moderators, measured with the instrument "Acceptability of Intervention Measure" (5-point Likert scale, higher score means better outcome) and additional custom question(s).
Time frame: During the ILI season (6 months).
Acceptability of physician implementation materials
Acceptability of implementation materials for physicians, measured with the instrument "Acceptability of Intervention Measure" (5-point Likert scale, higher score means better outcome) and additional custom question(s).
Time frame: During the ILI season (6 months).
Contextual and individual determinants of adoption
Determinants of adoption of the ARI guidelines identified through qualitative interviews, focus groups, and potentially quantitative data collection.
Time frame: Within 6 months after the ILI season.
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