The Role of Expert Witnesses in Medical Malpractice Cases
Medical malpractice litigation is among the most complicated areas of civil law, blending intricate medical facts with nuanced legal standards. In Illinois, as in many other jurisdictions, the role of expert witnesses is central to the effective adjudication of these cases.
Expert testimony helps bridge the knowledge gap between complicated medical procedures and legal principles, guiding judges and juries in determining whether a healthcare provider’s conduct deviated from the accepted standard of care and caused harm to the patient.
At Alberts, Curran, & Eiler P.C., our Illinois medical malpractice attorneys bring decades of experience with personal injury cases to make sure that the medical malpractice you experienced doesn’t go unnoticed.
Here, we’ll explore the pivotal role of expert witnesses in Illinois medical malpractice cases, including the qualifications of experts and their functions during litigation.
Medical Malpractice Law in Illinois
In Illinois, a medical malpractice claim arises when a healthcare provider, such as a doctor, nurse, or hospital, is alleged to have deviated from the accepted standard of medical care, resulting in injury or death to a patient. These cases are governed by both statutory law and common law, with significant procedural and evidentiary hurdles that plaintiffs must overcome.
Under Illinois law, to bring a medical malpractice claim, a plaintiff must establish the following elements:
A professional relationship existed between the patient and the medical provider.
The provider owed a duty of care to the patient.
The provider breached that duty by failing to adhere to the accepted standard of care.
The breach caused injury or death.
The patient suffered compensable damages as a result.
Due to the technical nature of medical treatment and standards, lay jurors often lack the expertise necessary to determine whether a provider’s actions were appropriate. As a result, expert witnesses are almost always necessary to establish both the standard of care and whether the defendant deviated from it.
Statutory Requirements for Expert Witnesses in Illinois
The following are a few legal provisions and certifications expert witnesses may require.
Section 2-622 Certificate of Merit Requirement
One statutory provision governing medical malpractice lawsuits in Illinois is 735 ILCS 5/2-622, known as the “certificate of merit” requirement. This mandates that a plaintiff filing a medical malpractice lawsuit must attach an affidavit stating they’ve consulted with a qualified healthcare professional who believes there’s a “reasonable and meritorious cause” for filing the action.
The affidavit must include a written report from the consulting healthcare professional, identifying:
Their qualifications;
Their review of the relevant medical records;
A statement that there is a reasonable and meritorious basis for the claim.
This requirement is designed to deter frivolous lawsuits by making sure that a licensed expert has preliminarily evaluated the claim and determined that a breach of the standard of care may have occurred. Failure to comply with Section 2-622 can result in dismissal of the case, although Illinois courts sometimes allow extensions for good cause.
Expert Qualifications
Illinois courts apply strict standards to assess whether an individual is qualified to testify as an expert in a medical malpractice case. An expert must have sufficient knowledge, education, training, and experience in the same or a similar field as the defendant healthcare provider.
In Sullivan v. Edward Hospital, 209 Ill. 2d 100 (2004), the Illinois Supreme Court emphasized the need for “foundational evidence” establishing an expert’s qualifications before they can render an opinion. The court requires that the expert’s opinion be grounded in reliable methods and procedures, not merely subjective belief or speculation.
Functions of Expert Witnesses in Medical Malpractice Litigation
Expert witnesses can hold multiple functions during a trial.
Establishing the Standard of Care
The first and most critical role of the expert witness is to define the applicable standard of care—the level of care, skill, and treatment that is recognized as acceptable and appropriate by reasonably prudent healthcare providers under similar circumstances. Without expert testimony, jurors would have no frame of reference to evaluate a provider’s actions.
For example, in a case involving delayed diagnosis of cancer, an oncologist might testify about the protocols and diagnostic procedures that a reasonably competent physician would have followed when presented with certain symptoms or test results. The expert's testimony provides a benchmark against which the defendant’s conduct is measured.
Proving Breach of Standard of Care
Once the standard of care is established, the plaintiff’s expert must also opine that the defendant breached that standard. This involves a detailed analysis of the defendant’s actions or omissions and how they diverged from accepted medical practice.
The expert must tie this breach directly to the facts of the case, using medical records, witness statements, and scientific literature. For instance, in a surgical error case, the expert might explain how a particular surgical technique deviated from industry norms, or how failing to monitor vital signs during anesthesia constituted a lapse in proper care.
Establishing Causation
Another essential function of the expert witness is to establish causation—the link between the breach of the standard of care and the plaintiff’s injury. This is often the most contested aspect of a malpractice case, as the defense may argue that the injury was due to an underlying condition, not negligence.
In Illinois, plaintiffs must prove proximate cause, meaning that the defendant’s actions were a substantial factor in bringing about the harm. The expert witness must articulate this connection with medical certainty. For example, an expert might testify that had a doctor properly diagnosed a condition earlier, the patient would have had a significantly higher chance of recovery.
Rebutting Defense Expert Testimony
In many cases, both the plaintiff and defense will retain their own expert witnesses, leading to a "battle of the experts." Plaintiff experts may also be called upon to rebut the conclusions of defense experts. This includes challenging the credibility, methodology, or interpretation of the defense expert’s analysis.
Skilled expert witnesses are often adept at identifying flaws or inconsistencies in the opposing expert's testimony, such as misapplication of medical guidelines or selective use of evidence.
Selection and Preparation of Expert Witnesses
Selecting the right expert can make or break a malpractice case. Attorneys typically look for experts who aren’t only qualified in the relevant specialty but also articulate, credible, and experienced in courtroom testimony.
Experts must be prepared to undergo rigorous cross-examination, so their demeanor, clarity, and ability to explain complicatedmedical issues in plain language are critical. It’s also important that the expert has no conflicts of interest and isn’t perceived as a “professional witness” whose income is largely derived from litigation work.
Preparing for Deposition and Trial
Before testifying, expert witnesses must be thoroughly prepared by legal counsel. This includes reviewing all relevant medical records, discussing anticipated lines of questioning, and preparing for potential challenges to their methodology and conclusions.
Deposition testimony is particularly important, as it can be used to impeach the expert at trial if they deviate from earlier statements. Therefore, consistency and clarity in deposition are vital.
Challenges to Expert Witness Testimony
You may encounter the following challenges when using expert witnesses in court.
Daubert and Frye Standards
Illinois uses the Frye standard to assess the admissibility of expert testimony. Under this standard, expert opinions must be based on methods that are "generally accepted" in the relevant scientific or medical community.
In Donaldson v. Central Illinois Public Service Co., 199 Ill. 2d 63 (2002), the Illinois Supreme Court held that Frye remains the applicable standard in Illinois state courts, unlike federal courts that use the more flexible Daubert standard. A Frye hearing may be requested to determine whether the expert’s methods meet this threshold.
Motions to Bar Experts
Parties may file motions in limine to exclude expert testimony on various grounds, such as lack of qualifications, methodological flaws, or bias. If granted, such motions can significantly weaken a party’s case.
For example, if a court finds that an expert’s testimony is based on insufficient data or speculative reasoning, it may be deemed inadmissible. This highlights the importance of thorough vetting and preparation of expert witnesses.
Ethical and Legal Considerations
Expert witnesses have ethical obligations to provide honest, objective opinions. They shouldn’t act as advocates for the side that retained them but rather as impartial educators to the court or jury.
Experts can be disqualified or sanctioned if they:
Overstate their qualifications;
Fail to disclose conflicts of interest;
Fabricate or misrepresent evidence;
Accept compensation contingent on the outcome.
Illinois law also prohibits “junk science” or testimony that lacks scientific grounding, which can undermine public trust in the legal system and medical profession.
Contact Us Today
Effective use of expert witnesses requires careful selection, rigorous preparation, and adherence to legal and ethical standards. That’s where Alberts, Curran, & Eiler P.C. comes in. We serve clients in Chicago, Northbrook, and throughout the state of Illinois. Reach out to us today.