## Facts

- Nikki Pooshs sued Philip Morris USA, Inc., alleging the company concealed and misrepresented facts about the addictive nature of nicotine in its cigarettes.
- As part of her case, Pooshs sought to present testimony on nicotine addiction and Philip Morris’s knowledge of nicotine’s addictiveness.
- Pooshs designated Dr. Valerie Yerger as a witness to testify about nicotine addiction.
- Yerger was a naturopathic physician and a public-health researcher whose work included reviewing tobacco-industry materials.
- Philip Morris moved to exclude Yerger’s testimony under Federal Rule of Evidence 702 and *Daubert*.
- The record did not show that Yerger was familiar with the diagnostic methods health professionals use to diagnose addiction.
- The record also did not show that Yerger had scientific training regarding nicotine’s effects on the human body.

## Issues

1. Whether Dr. Valerie Yerger was qualified under Federal Rule of Evidence 702 to give opinions on nicotine addiction and the diagnosis of nicotine addiction in a smoker.
2. Whether Yerger’s addiction-related opinions were the product of reliable principles and methods, and whether she reliably applied any such method to the case, as required by Rule 702 and *Daubert*.
3. Whether the proffered opinions would help the jury, or instead amount to unsupported conclusions or a narrative drawn from documents.

## Decision

- The court granted Philip Morris’s motion in substantial part and excluded Yerger’s proposed testimony on nicotine addiction and addiction diagnosis.
- The court found Yerger was not shown to have the training or experience needed to testify about clinical diagnosis of addiction or the physiological effects of nicotine on the body.
- The court also found the proffer failed to show a reliable, evaluable method connecting Yerger’s materials and experience to the medical and diagnostic conclusions she offered.

## Legal Principles

- Under Federal Rule of Evidence 702, opinion testimony from a witness may be admitted only if: (a) the witness is qualified by knowledge, skill, experience, training, or education; (b) the testimony will help the trier of fact; (c) the testimony is based on sufficient facts or data; (d) the testimony is the product of reliable principles and methods; and (e) those principles and methods are reliably applied to the facts.
- *Daubert* requires the trial court to act as a gatekeeper and exclude opinion testimony when the proponent does not show that the witness’s reasoning and method are reliably tied to the opinions offered, rather than resting on the witness’s say-so.
- A witness’s background must match the specific subject matter of the opinion; work in public health or document review does not, by itself, qualify a witness to offer clinical diagnostic opinions or physiological causation opinions.
- When an opinion involves medical diagnosis or human physiology, the proponent must show familiarity with accepted diagnostic standards or scientifically supported reasoning sufficient for the jury to evaluate the opinion’s basis.
- Courts may exclude opinion testimony that primarily summarizes documents or argues conclusions without a reliable method that bridges the gap between source materials and the ultimate opinion.

## Conclusion

In *Pooshs v. Phillip Morris USA*, the Northern District of California applied Rule 702 and *Daubert* to exclude Dr. Valerie Yerger’s proposed testimony on nicotine addiction, including diagnosis-related opinions, because Pooshs did not show that Yerger was qualified to opine on clinical addiction diagnosis or nicotine’s physiological effects, and did not show a reliable method connecting her materials to those medical conclusions.


Pooshs v. Phillip Morris USA, 287 F.R.D. 543 (2012)