This study looks at how checking patients before surgery affects problems that can happen around surgery time. When doctors check patients before surgery, they look at their health to find risks and make plans for before, during, and after surgery. This helps keep patients safe and can prevent surgeries from being canceled because of unexpected health issues.

Doctors call the time before, during, and after surgery the "perioperative period." If not handled well, it can lead to health problems and even death. In rich countries, 3-16% of patients have major issues during this time. The study aims to see if these checks really help in reducing problems.

• The study includes patients over 18 years having planned (elective) surgery.
• People cannot join if they need emergency surgery, are pregnant, or are over 80.
• Doctors will gather information by talking to patients and other healthcare workers.