What is the test for qualified expert testimony in medical malpractice cases?

"'A person is qualified to testify as an expert if he has special knowledge, skill, experience, training, or education sufficient to qualify him as an expert on the subject to which his testimony relates. Against the objection of a party, such special knowledge, skill, experience, training, or education must be shown before the witness may testify as an expert,' and 'may be shown by any otherwise admissible evidence, including his own testimony.' (Evid. Code, 720, subds. (a), (b).)" (People v. Tuggle (2012) 203 Cal.App.4th 1071, 1079.) "'The trial court's determination of whether a witness qualifies as an expert is a matter of discretion and will not be disturbed absent a showing of manifest abuse.' [Citations.]" (Ibid.)