The purpose of the study is to test the impact of the StOP?-protocol - an intra-operative communication briefing, on post-operative mortality and important patient outcomes.

The StOP?-protocol is a communication briefing initiated by the responsible surgeon during a surgical operation. The surgeon informs the team present in the operating room about the current Status of the operation, the Objectives of the next steps and the potential Problems the surgical team may meet; the responsible surgeon encourages the team to voice any question or concern (?).

To test the impact of the StOP?-protocol on patient outcomes, the study is designed as a randomized controlled trial. Surgeons will be randomized either (a) in the intervention group and be trained to perform the StOP?-protocol or (b) in the control group and will communicate as they prefer during their operations. Post-operative patient outcomes of the surgeons in the intervention and the control group will be compared to evaluate the effects of the StOP?-protocol.

For the clusters (surgeons)

Inclusion Criteria:

• Board-certified surgeons with specialization in one of the following disciplines: general, visceral, thoracic, vascular surgery, surgical urology, or gynecology.

Exclusion Criteria:

• Surgeons who are already performing StOP?-protocol. (Potentially, surgeons who took part in the first study (StOP-I) may still perform StOP?).
• Surgeon who were previously enrolled in the StOP?-II trial (this is relevant for surgeons who move or rotate between departments/hospitals and might therefore be working at different participating sites).

For the patients:

Inclusion criteria:

• Patients operated by cluster surgeons during the cluster-specific time period
• General consent from the patients, allowing the use of healthcare-related data that are the result of the patient's treatment. In case no written document from the general consent is available despite documented efforts of the participating center, article 34 HRA (Swiss law) will be applied, allowing the use of the healthcare-related patient data.

Exclusion criteria:

• Patient age below 18 years
• Previous operation at the same site up to 30 days prior the index operation
• Procedures not done in operating rooms but in outpatient clinics, on wards, etc.
• Mainly diagnostic endoscopic procedures (e.g. colonoscopy, gastroscopy, bronchoscopy)
• Percutaneous interventions (e.g., transurethral interventions)
• Documented refusal for the use of healthcare related data

Outcomes assessors will be blind whether the patients were operated by a surgeon in the control or in the intervention group.