Antibiotic resistance is an increasingly serious problem in Switzerland which is associated with the exposure and overall uptake of antibiotics in a population. Reduced antibiotic prescribing for outpatients is paralleled by a decrease in antibiotic resistance rates.

In a recent pragmatic trial, the investigators found only promising yet not very conclusive results as those were present only in some groups. This nationwide antibiotic stewardship program with routine feedback on antibiotic prescribing was not associated with an overall change in antibiotic use. In older children, adolescents, and younger adults fewer antibiotics were prescribed, but not consistently over the entire intervention period.

Hence, the investigators now aim to evaluate a better-tailored program to obtain a better understanding of the effects on patient-relevant outcomes, antibiotic resistance, and the underlying mechanisms leading to different effects in certain subgroups of patients.

The investigators plan to evaluate a nationwide antibiotic stewardship program combining routine prescription feedback with the provision of physician and patient education material for primary care physicians in Switzerland. The project is conducted within the framework of the National Program on antimicrobial resistance by the Swiss National Science Foundation. Also, additional subprojects will be done where we will assess the impact of COVID-19 on AB prescription by comparing the years 2017,2018, and 2019 with the year 2020 data.

This is a randomized pragmatic controlled trial in all primary care physicians in Switzerland e.g. the top 75% antibiotic prescribers. The trial is based on routinely collected individual reimbursement claims data of the three largest Swiss health insurers covering an estimated number of 3.8 million Swiss residents, and on routinely collected surveillance data on antibiotic resistance. A pragmatic trial design is used. Physicians in the intervention group will not have to provide informed consent but they may opt out and decline receiving any interventional information. Physicians in the control group will not be notified. This approach is justifiable and has previously been approved by all Swiss ethical committees. Investigators will take any measures to guarantee the confidentiality of all collected data. Data provided by health insurers on physicians and patients will be completely anonymized.

This is a nationwide study enrolling all registered primary care physicians (general internal medicine and pediatrics) with more than 100 patient contacts in the year prior to the start of the trial. All primary care providers with shared ZSR (Zahlstellenregister) numbers (e.g. ambulatory settings in hospitals where individual physicians cannot be identified) and with less than 100 patient contacts per year will be excluded.

Inclusion Criteria:

• Primary care physicians in Switzerland board certified with FMH (Foederatio Medicorum Helveticorum) title in general internal medicine or paediatrics & adolescent medicine, above the 25th percentile of antibiotic prescribing, consulting with at least 100 patients per year and with individual Zahlstellenregister number.

Exclusion Criteria:

• There are no exclusion criteria

For final data analysis the biostatistician will be blinded for treatment allocation of physicians.