Simply Statistics A statistics blog by Rafa Irizarry, Roger Peng, and Jeff Leek

Update On Theranos

By Roger Peng

I think it’s fair to say that things for Theranos, the Silicon Valley blood testing company, are not looking up. From the Wall Street Journal (via The Verge):

Theranos has voided two years of results from its Edison blood-testing machines, issuing tens of thousands of corrected reports to patients and doctors and raising the possibility that many health care decisions may have been made based on inaccurate data. The Wall Street Journal first reported the news, saying that many of the corrected tests have been run using traditional machinery. One doctor told the Journal that she sent a patient to the emergency room after seeing abnormal results from a Theranos test; the corrected report returned normal readings.

Furthermore, this commentary in JAMA from John Ioannides emphasizes the need for caution when implementing testing on a massive scale. In particular, “The notion of patients and healthy people being repeatedly tested in supermarkets and pharmacies, or eventually in cafeterias or at home, sounds revolutionary, but little is known about the consequences” and the consequences really matter here. In addition, as the title of the commentary would indicate, research done in secret is not research at all. For there the be credibility for a company like this, data needs to be made public.

I continue to maintain that the fundamental premise on which the company is built, as stated by its founder Elizabeth Holmes, is flawed. Two concepts are repeatedly made in the context of Theranos:

  • More testing is better. Anyone who stayed awake in their introduction to Bayesian statistics lecture knows this is very difficult to make true in all circumstances, no matter how accurate a test is. With rare diseases, the number of false positives is overwhelming and can have very real harmful effects on people. Combine testing on a massive scale, with repeated application over time, and you get a recipe for confusion.
  • People do not get tested because they are afraid of needles. Elizabeth Holmes makes a big deal about her personal fear of needles and it’s impact on her (not) getting blood tests done. I have no doubt that many people share this fear, but I have serious doubt that this is the reason people don’t get the medical testing done. There are many barriers to people getting the medical care that they need, many that are non-financial in nature and do not include fear of needles. The problem of getting people the medical care that they need is one deserving of serious attention, but changing the manner in which blood is collected is not going to do it.