Plaintiffs in this medical malpractice case appeal from a jury verdict of no cause of action for the defendant George D. Stilwill, M.D., and a directed verdict for the defendant Edward W. Sparrow Hospital Association. Three issues are raised by the plaintiffs on appeal:
(1) Whether the trial court committed reversible error by permitting the plaintiffs’ expert witness to be cross-examined about his involvement in other medical malpractice cases.
*596(2) Whether the remarks during closing argument by counsel for the defendant doctor indicating that his client did not utilize "professional witnesses” deprived plaintiffs of a fair trial and required a new trial.
(3) Whether the trial court committed reversible error by granting the defendant hospital’s motion for a directed verdict.
The Court of Appeals answered these questions in the negative and affirmed the jury verdict and the directed verdict. We agree, although in part for different reasons. Accordingly, we affirm the judgment of the Court of Appeals.
I. Facts
The plaintiff, Irving J. Wilson, experienced some problems and difficulty with his right arm. In November, 1970, he contacted the defendant Dr. Stilwill, an orthopedic surgeon. Dr. Stilwill diagnosed the problem to be the result of a non-union of an old fracture. Dr. Stilwill advised Mr. Wilson that he could perform a compression-plating procedure by which the non-union could be corrected.
Surgery was performed on December 11, 1970, at the defendant Edward W. Sparrow Hospital. Following surgery Mr. Wilson experienced difficulty moving the fingers of his right hand. Signs of infection developed. Five days after the operation culture and sensitivity tests were ordered by Dr. Stilwill. The infection was identified and treated with antibiotics. Following his release from Sparrow Hospital, Mr. Wilson complained of pain, swelling, and a discharge from his arm. Additional tests indicated the presence of different bacteria. Subsequently, a number of additional surgical pro*597cedures were performed at the hospital. Mr. Wilson’s right arm is now paralyzed.
Mr. and Mrs. Wilson brought this action against Dr. Stilwill and Edward W. Sparrow Hospital for malpractice. At the close of the plaintiffs’ proofs the trial court directed a verdict for the hospital. The jury returned a verdict of no cause of action for the defendant Dr. Stilwill. The trial court denied the plaintiffs’ motion for new trial. The Court of Appeals affirmed. 92 Mich App 227; 284 NW2d 773 (1979). We granted leave to appeal. 408 Mich 898 (1980).
II. Cross-Examination
The first issue pertains to a line of questioning on cross-examination directed to the plaintiffs’ expert witness, W. O. Badgley, M.D., by counsel for the defendant Dr. Stilwill. Responding to inquiries as to whether he was still actively treating patients, Dr. Badgley testified that 40% of his practice had to do with disability evaluation. He stated: "Sixty percent comes from the care of patients.” The doctor explained that attorneys referred patients to him for disability evaluation and reports as to the extent of their injuries. Dr. Badgley confirmed the fact that he gives testimony or his opinions concerning the evaluations. He also testified that he had not been involved in more than two or three cases in which there was alleged malpractice. In two cases the attorney for the plaintiffs was the same attorney representing the plaintiffs in the instant case. When questioned about a third malpractice case, Dr. Badgley stated that he did not recall that case and that he had never testified.
At that point, plaintiffs’ counsel objected. The trial court permitted the questioning to continue. *598Dr. Badgley then recalled that he had been asked his opinion on that case, but that he had nothing to do with the case. After he testified that he had no recollection of two other cases, the plaintiffs’ attorney again objected. The objection was sustained. There was no motion to strike any testimony, nor any request for a curative or limiting instruction.
The plaintiffs contend that the trial court erred when it initially overruled the objections of plaintiffs’ counsel and that in any event the evidence introduced deprived the plaintiffs of a fair trial. It is the claim of the plaintiffs that the cross-examination of Dr. Badgley was calculated to convey to the< jury the innuendo that there was complicity between the expert witness and the plaintiffs’ attorney. Plaintiffs urge that this line of questioning was intended to improperly divert the attention of the jury from the issues of malpractice and to focus upon the credibility of the witness in an effort to prejudice the jury.
In response, the defendant doctor asserts that the scope of cross-examination is subject to the trial court’s discretion. In this case, defense counsel was attempting to impeach the expert witness by showing that he was involved in more than two or three malpractice cases. Furthermore, the inquiry was also designed, within proper bounds, to elicit testimony indicative of bias or prejudice. Defense counsel sought to establish that Dr. Badgley had previously testified in malpractice suits at the request of plaintiffs’ attorney and that the witness had almost always been involved in cases on behalf of a plaintiff. This background information, defendant urges, is appropriate for the jury to evaluate in weighing the import of the expert opinion.
*599The scope and duration of cross-examination of witnesses rests in the sound discretion of the trial court. The exercise of this discretion will not be reversed absent a clear showing of abuse. See, e.g., People v Taylor, 386 Mich 204; 191 NW2d 310 (1971). See also Hayes v Coleman, 338 Mich 371; 61 NW2d 634 (1954) (broad scope of cross-examination to show bias or prejudice). There is "a general canon that on cross-examination the range of evidence that may be elicited for any purpose of discrediting is to be very liberal." 3A Wigmore, Evidence (Chadbourn Rev), § 944, p 778.
The primary issues in most medical malpractice cases are: what is the appropriate standard of care, whether there was a breach of this standard of care and whether the breach was a proximate cause of plaintiffs injuries. Both parties in most cases call upon expert witnesses to testify on these issues. In this "battle of experts” credibility is a primary question for consideration by the jury.
The trial judge is charged with the responsibility, in his or her discretion, of permitting and limiting attacks on credibility. He or she must insure that questions seeking to elicit evidence indicating bias, prejudice or interest and inconsistent testimony or statements are not unduly limited or improvidently extended. The trial judge also must be alert to questions which harass, intimidate or belittle a witness.
The fact that a substantial part of Dr. Badgley’s practice involves giving disability evaluations and preparing reports of his findings and conclusions is not an improper subject for general limited inquiry. An expert witness’s experience testifying in court may influence the manner in which he or she testifies. The same is true for experience in evaluating cases which may come to court. It is *600thus proper to bring out on cross-examination the number of times a witness testifies in court, or is involved in particular types of cases. See Rumptz v Leahey, 26 Mich App 438; 182 NW2d 614 (1970).
In DeHaan v Winter, 262 Mich 192; 247 NW 151 (1933), (After Remand) 265 Mich 101; 251 NW 391 (1933), our Court held that permitting cross-examination of an expert witness concerning his interest in the event of suit was not error. DeHaan is a medical malpractice case. The expert medical witness and the defendant doctor belonged to the state medical society. A small portion of the society’s dues went to the defense of malpractice suits for members.
"For the purpose of affecting credibility of the witness, he may be cross-examined as to his interest in the event of suit, including contribution to the expense of it.” DeHaan, 262 Mich 195.
Evidence concerning the fact that Dr. Badgley had testified at the request of the plaintiffs’ counsel in other malpractice cases, like the testimony in DeHaan, is a permissible subject of cross-examination for the purpose of affecting credibility. The cross-examination of Dr. Badgley minimally concerned possible bias or prejudice. See Ager v Baltimore Transit Co, 213 Md 414; 132 A2d 469 (1957). A showing of a pattern of testimony for a particular attorney in past cases raises a possible inference that the witness has testified in such a manner that he would be hired in future cases.1 See *601Collins v Wayne Corp, 621 F2d 777, 784 (CA 5, 1980). See also Treece v The Greyhound Bus Co, 63 Mich App 63, 66; 234 NW2d 404 (1975); Gutowski v M & R Plastics & Coating, Inc, 60 Mich App 499, 505, fn 2; 231 NW2d 456 (1975). In response, additional inquiry would be permissible to show that the witness had been called by many other lawyers on various issues over the years. The jury, in the trial court’s discretion, may hear and evaluate evidence affecting credibility.
Counsel for the plaintiffs first raised an objection to the cross-examination when questions were raised concerning Dr. Badgley’s involvement in malpractice cases as a witness for the injured party where it did not appear that plaintiffs’ counsel was involved. The trial court initially permitted the questioning to continue. When Dr. Badgley could not recollect any involvement in two cases, plaintiffs’ counsel objected and the objection was sustained.
A pattern of testifying as an expert witness for a particular category of plaintiffs or defendants may suggest bias.2 However, such testimony is only minimally probative of bias and should be carefully scrutinized by the trial court.3
*602In the instant case the trial court did not commit reversible error, nor abuse its discretion, by permitting the cross-examination covering these areas of inquiry to continue within limited bounds. Furthermore, an objection was not raised until after Dr. Badgley had described his involvement in malpractice cases and had testified as to his relationship with the plaintiffs’ counsel.
III. Closing Argument
Plaintiffs contend that their expert, Dr. Badgley, was characterized as a "professional witness” by counsel for Dr. Stilwill in his closing argument and that this statement denied plaintiffs a fair trial. In his closing argument defendant Dr. Stilwill’s counsel stated:
"In an attempt, ladies and gentlemen, to find out the most probable cause of Mr. Wilson’s injury we went to the two largest at least [sic] medical institutions in the State of Michigan. We went to the University of Michigan and we went to Henry Ford Hospital. And we got there, and we went to the sub-department of internal medicine, the medical practice of infectious diseases. *603We did not go to professional witnesses; we went to professional physicians qualified better than any other man [sic] in the State of Michigan, to the best of our knowledge, to determine the answers to the questions. What caused the infection; and, secondly, could the infection work so fast as to cause paralysis in Mr. Wilson’s hand which was evidenced by the time he regained full consciousness? We gave them all of the facts, and in Cox’s [one of the defendant doctor’s experts] hypothetical we used facts most favorable to the plaintiff, and he said there was no evidence of malpractice.”
In his rebuttal argument plaintiffs’ counsel stated:
"[A]s a matter of fact, when you go into the jury room, if there is any inference that [Dr. Badgley] is a bad person for coming in here and testifying, there is a bill in here from Dr. Badgley; he examined the man [in] November of 1975, and it is Exhibit No. 24, and he charged $100.20. I asked him about that. Do you really think that Dr. Badgley came in here and testified for $100.20?
"I think you should settle back and listen to what he said, not try to talk about professional witnesses and the like because it is unfair, unjust to my client to say that.”
When the jury was excused after closing arguments, counsel for the plaintiffs requested the trial court to instruct the jury to disregard defense counsel’s "professional witness” statement or, in the alternative, to give a cautionary instruction.
Defendant doctor’s counsel attempted to explain that his comment did not refer to Dr. Badgley, plaintiffs’ expert witness. It was argued that the statement about professional witnesses was based upon defense counsel’s concern about any unfavor*604able inference that the experts called by the defendant doctor were professional witnesses because these expert witnesses were not from the immediate area.
The trial court did not recall any specific reference to Dr. Badgley, and even if there was, the trial court indicated the statement might have constituted fair comment under all the circumstances of the case. The trial court denied the request for a special instruction. The trial court’s instructions to the jury did include, however, the general instruction that arguments, statements and remarks of attorneys are not evidence and that the jury should disregard anything said by an attorney which is not supported by evidence.
The Court of Appeals agreed with the trial court’s ruling and concluded that even if the statement was directed toward plaintiffs’ expert, the statement was a reasonable inference from the testimony and amounted to a fair characterization of the witness. The Court of Appeals opinion referred to the testimony of plaintiffs’ expert that approximately 40% of his income was derived from the evaluation of medical disability cases and that he had been involved in a number of medical malpractice cases.
We do not agree with the conclusion that the "professional witness” statement, assuming it was directed toward Dr. Badgley, was a fair characterization of the witness. The evidence merely showed that Dr. Badgley had been involved in a few medical malpractice cases. There was no evidence indicating that the doctor frequently testified. Furthermore, Dr. Badgley derived 60% of his income from the care of patients.
However, the failure of the trial court to give the requested instruction does not require reversal *605and a new trial in this case.4 The reference to Dr. Badgley was indirect. The request for an instruction was made after the plaintiffs’ lawyer had responded to the statement in his rebuttal argument. The trial court did instruct the jury that statements in closing argument are not evidence. Furthermore, the conduct of the defendant doctor’s counsel in questioning Dr. Badgley and in arguing to the jury did not deprive plaintiffs of a fair trial under the circumstances of this case.
This Court has not hesitated to require a new trial when attorneys, through questioning and argument, have shown a studied purpose to prejudice the jury.
In Wayne County Board of Road Comm’rs v GLS LeasCo, 394 Mich 126, 139; 229 NW2d 797 (1975), this Court ordered a new trial because the board’s attorney repeatedly belittled and harassed witnesses and opposing counsel even after objections were sustained. Witnesses were accused of lying and of fabricating evidence. The board’s lawyer suggested that opposing counsel and LeasCo executives "bought” testimony.
"A substantial doubt regarding the fairness of the trial has been raised by the egregious and repetitive nature of the misconduct of the board’s lawyer.”
In Kern v St Luke’s Hospital Ass’n of Saginaw, 404 Mich 339, 354; 273 NW2d 75 (1978), counsel for the defendants
"continuously raised the groundless charge, by direct attack and innuendo, that the 'bought’ testimony of plaintiffs’ out-of-state expert witnesses was collusive and untrue.”
*606Defense counsel in Kern improperly and repeatedly attempted to show a conspiracy to render false testimony. Defense counsel referred to one of plaintiffs’ experts as " 'the fellow that came in here to do my client in’ ”. Kern, 351. The conduct of defense counsel in Kern was perceived as "a studied purpose to prejudice the jury”. Kern, 354.
The conduct of the attorney for the defendant doctor in the instant case was not the type of egregious and repetitive conduct that was present in LeasCo and Kern. The record reflects no studied purpose to prejudice the jury. The questioning on cross-examination of Dr. Badgley did not harass or belittle the witness. There were no accusations of lying. After the trial court sustained the objection by plaintiffs’ attorney, the questioning stopped. There was only a single and indirect improper comment in closing argument.
We therefore conclude that neither the questioning on cross-examination of Dr. Badgley, nor the closing argument of the defendant doctor’s counsel warrant setting aside the jury’s verdict in this case.
IV. Directed Verdict
A
At the close of the plaintiffs’ proofs the trial court directed a verdict for the defendant hospital. Plaintiffs contend that the case should have been submitted to the jury under the doctrine of res ipsa loquitur, as the mere occurrence of the infection in Mr. Wilson’s arm is sufficient to establish an issue for the jury to consider.
Plaintiffs rely upon four conditions for the application of res ipsa loquitur set forth in Gadde v *607Michigan Consolidated Gas Co, 377 Mich 117, 124; 139 NW2d 722 (1966):5
"1. The event must be of a kind which ordinarily does not occur in the absence of someone’s negligence.
"2. The event must have been caused by an agency or instrumentality within the exclusive control of the defendant.
"3. The event must not have been due to any voluntary action or contribution on the part of the plaintiff.
"4. Evidence of the true explanation of the event must be more readily accessible to the defendant than to the plaintiff.” (Emphasis deleted.)
The Court of Appeals, relying upon another infection case, Rohdy v James Decker Munson Hospital, 17 Mich App 561; 170 NW2d 67 (1969), lv den 383 Mich 756 (1969), rejected the plaintiffs’ argument. We agree with the Court of Appeals.
The threshold question with respect to this issue is whether an infection ordinarily does not occur in the absence of negligence.
The testimony showed that the defendant hospital had a post-operative infection rate well below the national average. At least three physicians who testified indicated that infections which are not the result of any breach of due care can and do occur during surgery. There was no testimony to the contrary. Plaintiffs’ expert witness described proper sterilization procedures which were consistent with the testimony given for the defendants. Furthermore, there was no testimony suggesting a break in sterile technique.
The plaintiffs suggest that the low incidence of *608infection at the defendant hospital means that infection does not ordinarily occur. From this statement they seek to apply res ipsa loquitur. Although it is true that statistically infections did not ordinarily occur at the defendant hospital, this fact does not suggest that when an infection does occur, it is the result of negligence.
"The requirement that the occurrence be one which ordinarily does not happen without negligence is of course only another way of stating an obvious principle of circumstantial evidence: that the event must be such that in the light of ordinary experience it gives rise to an inference that some one must have been negligent.
"In the usual case the basis of past experience from which the conclusion may be drawn that such events usually do not occur without negligence is one common to the whole community, upon which the jury are simply pérmitted to rely. Even where such a basis of common knowledge is lacking, however, expert testimony may provide a sufficient foundation; and by the same token it may destroy an inference which would otherwise arise.” Prosser, Torts (4th ed), § 39, pp 214, 217.
The mere occurrence of a post-operative infection is not a situation which gives rise to an inference of negligence when no more has been shown than the facts that an infection has occurred and that an infection is rare. See, e.g., Shurpit v Brah, 30 Wis 2d 388; 141 NW2d 266 (1966); McCall v St Joseph’s Hospital, 184 Neb 1; 165 NW2d 85 (1969); Contreras v St Luke’s Hospital, 78 Cal App 3d 919; 144 Cal Rptr 647 (1978).
Since we have determined that plaintiffs have not met the threshold requirement for an inference of negligence, their reliance upon Ybarra v Spangard, 25 Cal 2d 486; 154 P2d 687 (1944), as *609authority for placing the burden upon the defendants to explain their conduct is inapposite. The Ybarra court concluded that the event must be of the kind which ordinarily does not occur in the absence of negligence. Only when this initial point is shown would the burden be placed upon the defendants to explain their conduct.
B
The plaintiffs also contend that the trial court erred by directing a verdict for the hospital because they were prevented from arguing agency by estoppel as set forth in Howard v Park, 37 Mich App 496; 195 NW2d 39 (1972), lv den 387 Mich 782 (1972). The Court of Appeals did not address this issue. The defendant hospital argues that this issue was not preserved for appeal.
The plaintiffs’ complaint alleged that the hospital, through its agents and employees, allowed the operating room and the materials used during surgery to be unclean, which caused the post-operative infection. In the Court of Appeals the plaintiffs argued that Dr. Stilwill was an agent by estoppel of the hospital. Even if properly preserved, we conclude that the issue is without merit.
In Grewe v Mount Clemens General Hospital, 404 Mich 240; 273 NW2d 429 (1978), we held that, under the doctrine of agency by estoppel, or ostensible agency, a hospital may be held liable for the acts of medical personnel who were its ostensible agents although the named defendant physician is not found liable. In Grewe, as in Howard v Park, the plaintiff looked to the hospital for treatment of his physical ailments and did not merely view the hospital as the situs where his physician would treat him. In neither of these cases did the plain*610tiffs have an independent relationship with the allegedly negligent physician prior to admission to the hospital.
In the instant case there was an independent physician-patient relationship prior to the hospital treatment. Furthermore, as to the claim that Dr. Stilwill was an agent of the hospital, the jury’s determination of no cause of action for defendant Dr. Stilwill prevents imposing liability upon the hospital for Dr. Stilwill’s actions. See Lamb v Oakwood Hospital Corp, 41 Mich App 287; 200 NW2d 88 (1972).
We have determined that the mere occurrence of the post-operative infection is insufficient to establish an issue for consideration by the jury. There is no testimony to indicate that the operating room or surgical materials were unclean. The only possibility for imposing liability upon the hospital would be if one or more of its ostensible agents or employees acted negligently by failing to prevent the infection. Since the question of negligence concerning the infection was properly withdrawn by the trial court from consideration by the jury, it was also proper to withdraw any claim based upon the doctrine of agency by estoppel.
C
The plaintiffs further argue that the jury should have been permitted to consider their claim that the hospital was negligent by failing to establish standards of conduct which would have required doctors or other qualified personnel to remain in attendance on Mr. Wilson after surgery to ascertain if an infection would develop, when they knew or should have known of the possibility. The trial court directed a verdict on this claim for the hospital because the plaintiffs failed to introduce *611any expert testimony to establish the standard of conduct.
The plaintiffs contend that this case presents a question of ordinary negligence and that no expert testimony was necessary. With respect to this assertion, it seems evident that whether a hospital’s negligence must be shown by expert testimony depends on the circumstances of the particular case. The plaintiffs rely on two cases in support of their theory. Fogel v Sinai Hospital of Detroit, 2 Mich App 99; 138 NW2d 503 (1965), clearly involved a case of ordinary negligence. Fogel had warned a nurse’s aide that one aide was not capable alone of helping her get to the bathroom. The aide could not hold her and she fell and fractured her hip. Gold v Sinai Hospital of Detroit, Inc, 5 Mich App 368; 146 NW2d 723 (1966), also held that a patient’s fall in a hospital was a matter of ordinary negligence. However, these cases presented issues which are within the common knowledge and experience of a jury.
In contrast to Fogel and Gold, the instant case presents a standard of conduct issue which cannot be determined by common knowledge and experience, but rather raises a question of medical judgment. If questions regarding this standard were presented in a malpractice case involving a physician or dentist, expert testimony would be required to establish the standard. See, e.g., Lince v Monson, 363 Mich 135; 108 NW2d 845 (1961); Roberts v Young, 369 Mich 133; 119 NW2d 627 (1963); Wrobel v Cotman, 372 Mich 383; 126 NW2d 723 (1964). Similarly, when a medical malpractice action not involving ordinary negligence is brought against a hospital, as a general rule, expert testimony is required. See, e.g., Bivens v Detroit Osteopathic Hospital, 77 Mich App 478; *612258 NW2d 527 (1977), rev’d on other grounds 403 Mich 820 (1978); Brandon v Art Centre Hospital (Osteopathic), 366 F2d 369 (CA 6, 1966).
We have reviewed the testimony in the light most favorable to the plaintiffs and have drawn the reasonable inferences therefrom which are in their favor. Dodd v Secretary of State, 390 Mich 606, 612; 213 NW2d 109 (1973). We conclude that the trial judge properly granted the directed verdict for the hospital.
The trial judge did not commit reversible error. The plaintiffs were not denied a fair trial.
Accordingly, we affirm the judgment of the Court of Appeals. Costs to the defendants.
Coleman, C.J., and Fitzgerald and Ryan, JJ., concurred with Blair Moody, Jr., J.This Court does not suggest that Dr. Badgley’s testimony has ever been influenced by his relationship with the plaintiffs’ counsel. The Court’s close analysis of the transcript reveals Dr. Badgley to be a concerned and dedicated physician. Furthermore, we recognize that expert witnesses, particularly in medical malpractice cases, furnish testimony that is essential to the truth-seeking trial process. Nevertheless, when permitted by the trial court, the jury may evaluate *601such relationships and "dedication cannot insulate anyone from the suggestions of bias that a cross-examiner brings out when he plays his role in a trial”. Collins v Wayne Corp, 621 F2d 777, 784, fn 5 (CA 5, 1980).
3 Kramer, Medical Malpractice (New York: Matthew Bender, 1980), ¶ 29.08, pp 29-76 to 29-77. See also Graham, Impeaching the Professional Expert Witness by a Showing of Financial Interest, 53 Ind L J 35 (1977).
Attorneys representing injured persons advocate cross-examining a defendant’s expert witness concerning the frequency of testifying in previous medical malpractice cases. See Kramer, Cross-Examination of the Medical Expert, 13 Trial 26, 27 (Dec, 1977).
The Michigan Rules of Evidence, adopted after the trial in the instant case, confer reasonable discretion upon the trial judge to admit or exclude evidence and to control the cross-examination of witnesses. This discretion includes, inter alia, decisions to permit *602questions concerning a witness’s history of testifying in court and the problems, if any, in securing the necessary expert testimony.
MRE 403 supplies sufficient guidance:
"Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.”
MRE 611 provides in part:
"(a) Control by court. The court shall exercise reasonable control over the mode and order of interrogating witnesses and presenting evidence so as to (1) make the interrogation and presentation effective for the ascertainment of the truth, (2) avoid needless consumption of time, and (3) protect witnesses from harassment or undue embarrassment.
"(b) Scope of cross-examination. A witness may be cross-examined on any matter relevant to any issue in the case, including credibility.”
GCR 1963, 529.1.
Michigan has not formally adopted the doctrine of res ipsa loquitur. However, the underlying concepts of res ipsa loquitur, which are circumstantial evidence and negligence concepts, have been applied in Michigan. Gadde v Michigan Consolidated Gas Co, 377 Mich 117; 139 NW2d 722 (1966).