What is the test for a court to refuse to admit expert testimony in a medical malpractice case?

In the present case, the trial court did not abuse its discretion in refusing to admit the expert testimony. At the outset, we reject appellant's assertion on appeal that the trial court "based its ruling solely on relevance." The court referred to Evidence Code section 352 several times and expressly identified its concerns regarding the undue prejudice and confusion that could result from admission of the expert testimony. (See People v. Doolin (2009) 45 Cal.4th 390, 438 [" 'a court need not expressly weigh prejudice against probative value or even expressly state that it has done so, if the record as a whole shows the court was aware of and performed its balancing functions under Evidence Code section 352' "].)