## Facts

- Boyce E. Chumbler, injured in an electrical explosion, consulted Nashville neurosurgeon Dr. C. C. McClure, Jr. in April 1971.
- Dr. McClure diagnosed “cerebral vascular insufficiency” and prescribed Premarin (an estrogen manufactured by Ayerst Laboratories, Inc.) and Pavabid (a vasodilator).
- Chumbler alleged he suffered adverse effects, including breast enlargement and loss of libido, and sought damages.
- Chumbler sued in federal court under diversity jurisdiction, asserting (1) medical malpractice against Dr. McClure’s estate and (2) negligence-based product liability against Ayerst, including an alleged failure to warn.
- At trial, the district court directed a verdict for Ayerst at the close of Chumbler’s case and directed a verdict for Dr. McClure’s estate at the close of all proof.
- The court excluded Chumbler’s testimony about his conversations with Dr. McClure regarding risks and consent under Tennessee’s Dead Man’s Statute.

## Issues

1. In a diversity case, whether Tennessee’s sufficiency-of-the-evidence standard governed review of directed verdicts.
2. Whether Chumbler presented material expert proof that Dr. McClure’s diagnosis and drug therapy fell below the applicable community standard of care under Tennessee malpractice law.
3. Whether Chumbler presented evidence permitting a reasonable jury to find Ayerst negligent in manufacturing or marketing Premarin, including by providing inadequate warnings to the medical profession.
4. Whether the exclusion of Chumbler’s testimony about conversations with the deceased physician under Tennessee’s Dead Man’s Statute was error affecting his informed-consent theory.

## Decision

- The Sixth Circuit affirmed the judgments for both defendants.
- The court applied Tennessee’s sufficiency-of-the-evidence standard for directed verdicts in diversity cases.
- The court held the malpractice claim failed because the record lacked competent expert evidence establishing a deviation from accepted medical practice in the relevant community; differences in medical judgment did not establish negligence.
- The court held the product-liability claim failed because the evidence did not show negligent manufacture/quality control or inadequate warnings attributable to Ayerst.
- The court held Tennessee’s Dead Man’s Statute properly barred Chumbler’s testimony about transactions or conversations with the deceased physician, and the evidentiary ruling left insufficient proof to submit informed consent or related negligence theories to the jury.

## Legal Principles

- In diversity cases, state law controls the standard for evaluating sufficiency of evidence on motions that remove a case from the jury, including directed verdicts.
- Under Tennessee’s directed-verdict standard, a case may be taken from the jury when the evidence permits only one reasonable conclusion.
- Tennessee medical-malpractice liability requires competent expert proof of (1) the applicable standard of professional care in the relevant community and (2) a deviation from that standard; a mere difference of medical opinion or unfavorable outcome is insufficient.
- Negligence-based claims against prescription-drug manufacturers require evidence of actionable conduct such as negligent manufacture or inadequate warnings; absent such proof, submission to the jury is improper.
- Tennessee’s Dead Man’s Statute bars an interested party from testifying about transactions with a deceased party, and the resulting evidentiary limits may be dispositive where excluded testimony is central to consent or disclosure allegations.

## Conclusion

The Sixth Circuit affirmed directed verdicts for the physician’s estate and the drug manufacturer because, applying Tennessee’s sufficiency and evidentiary rules, the admissible proof did not provide material evidence of malpractice, negligent manufacture, or inadequate warnings, and the Dead Man’s Statute properly foreclosed the plaintiff’s testimony about consent-related conversations with the deceased physician.


Chumbler v. McClure, 505 F.2d 489 (6th Cir. 1974)