Primary goal: To test the effects of short intrasurgical briefings on patient outcomes (surgical site infections [SSI] , mortality) in a clinical intervention study. Secondary goal: To investigate the effects of intrasurgical briefings on intrasurgical communication, team informedness and quality of teamwork in an observational study. Rationale: To improve patient safety and minimize the risk of iatrogenic harm is a priority in healthcare. SSI is the most frequent, and a very costly, complication after surgery. In a previous study, we established the methodology for intraoperative observations and observed significant relationships between intrasurgical communication and SSI. In particular, we found that increased case-relevant communication during the procedure was associated with a reduction in organ/space SSI, whereas more case-irrelevant communication during the closing phase of the procedure was associated with an increase of incisional SSI. These findings are interpreted in light of previous studies showing that explicit task-relevant communication fosters the development of shared mental models in the team, which facilitates coordination. Conversely, task-irrelevant communication seems to divert attention. Methods: This multicenter prospective two-arm observational study uses an interrupted time-series approach and will be performed in five clinical departments in Switzerland. Data of about 4000 surgeries per year will be included. Baseline measures are performed during 9 months, followed by one month of intervention (introduction and training), which is followed by an evaluation of the intervention during 9 months per center. The intervention comprises clinically applicable, short intrasurgical briefings that foster the exchange of case-relevant communication during surgeries without interfering with the surgical task. A short (2 min) structured team briefing intervention with the acronym StOP? (Status, Objectives, Problems, Questions) will be introduced at specific points of the procedure (after exposing the organs; after team member changes; before closure). Briefings will be accompanied by structural changes in the operating room (transparent draping and delaying the cleaning at the end of the operating) that should improve communication. Pilot trials confirmed the feasibility of the intervention. The secondary goal will be investigated by a study that directly observes communication and teamwork in the OR in comparable surgeries before and after the intervention. About 160 surgeries will be observed. Significance: The study design allows addressing a clinically relevant outcome parameter. We expect that short intrasurgical briefings will - similar to a preoperative time-out – improve quality of surgery, thereby reducing patient complication rates. The project investigates specific aspects of intrasurgical communication and the consequences of attention-focusing interventions on communication patterns in complex tasks of multidisciplinary teams. Interdisciplinary cooperation between medicine and psychology is a prerequisite for this study, because medical and behavioral data will be addressed simultaneously, and the study is based on medical and psychological knowledge.