The common practice of double-booking a lead surgeon’s time and letting junior physicians supervise and complete some parts of a surgery is safe for most patients, a study of more than 60,000 operations finds. But there may be a small added risk for a subset of patients.

The common practice of double-booking a lead surgeon’s time and letting junior physicians supervise and complete some parts of a surgery is safe for most patients, a study of more than 60,000 operations finds. But there may be a small added risk for a subset of patients.