Nurse Practitioner Expert May Opine on Treatment of Psychological Symptoms, Not Causation

    Court: United States District Court for the Western District of Kentucky, Owensboro Division
    Jurisdiction: Federal
    Case Name: Brooks v. Caterpillar Global Mining Am., LLC
    Citation: 2017 U.S. Dist. LEXIS 193184

    A nurse practitioner expert witness’s diagnosis of a plaintiff’s physiological symptoms is admissible if it’s based on the patient’s history, objective tests, and observations. Nurse practitioner expert witnesses may not, however, opine the cause of a plaintiff’s psychological symptoms without sufficient evidence.


    The plaintiff, a coal miner, filed a product liability lawsuit against the defendant claiming damages for injuries suffered during a mining accident. The plaintiff alleged the accident occurred due to a faulty operator handle of a roof bolter manufactured by the defendant. The faulty handle allegedly left the plaintiff’s hand unprotected and caused his hand to be crushed between the roof bolter and a rib of coal.

    The plaintiff retained a nurse practitioner expert witness to support his claims. The defendant challenged the nurse practitioner expert’s testimony on the grounds that it did not meet the standards set by Daubert v. Merrell Dow Pharmaceuticals, Inc. and Rule 702 of the Federal Rules of Civil Procedure. The defendant moved the court to prohibit the expert from opening on injuries caused by the accident and their effect on the employment opportunities open to the plaintiff, arguing that her opinions were unreliable and irrelevant because she was not qualified to testify about medical causation, employment opportunities, or psychological issues.

    The Nurse Practitioner Expert

    The plaintiff’s nurse practitioner expert witness had 18+ years of experience providing nurse practitioner services to families as an advanced practice registered nurse. She was associated with a community hospital in Greenville, Kentucky, where she rendered primary care services to patients, including diagnoses, assessments, and treatments. She also had permission to prescribe medication. The nurse practitioner expert witness had extensive experience assessing pain suffered by patients, including pain caused by injuries and neuropathic pain. The expert was the plaintiff’s primary health care provider and treated his psychological conditions along with the symptoms presented in other body parts.


    The court found the expert to be sufficiently qualified to offer testimony about the diagnosis, prognosis, and treatment of the plaintiff’s physiological symptoms, noting that it’s “within the normal range of duties for a health care provider to develop opinions regarding causation and prognosis during the ordinary course of an examination,” citing Fielden v. CSX Transp., Inc.

    The court, however, precluded the nurse practitioner expert from testifying as to the cause of the plaintiff’s psychological symptoms, as she could not prove their causation from the accident. The court was of the opinion that her testimony suggesting alternative employment for the plaintiff was relevant as it would have refuted any contentions the defendant might have raised about his work ethic, and was thus admissible.

    The court further noted that the expert’s methodology of using patient history before performing physical examination in order to reach a diagnosis about the physiological symptoms presented by the plaintiff was a part of diagnosis and treatment procedure used by medical health professionals, thus rejecting the defendant’s argument that it was merely based on what the plaintiff had told her. The court said that the expert’s diagnosis about the plaintiff’s “pain and neuropathic pain” being permanent was based on sufficiently reliable methodology, as she had depended on the plaintiff’s subjective complaint of pain along with the objective tests and observations she had performed on the plaintiff.


    The defendant’s motion to exclude the testimony of the plaintiff’s nurse practitioner expert witness was granted in part and denied in part.