Most teachers of evidence-based-medicine talk about tests as “positive, or negative”. A positive test is one in which the result of the test is abnormal; a negative test is one in which the test’s result is normal. A problem with this way of teaching about the value of test results is that often physicians and patients think there are only two possible test results, normal or not. However, test results are never just, “normal or abnormal”; test results may take on many values, not just two. ,
Researchers distinguish normal test results by performing the test in people who are well. For example, 100s of normal people will have blood tests done and the test results will vary over a narrow range. A serum potassium test result may be as low as 3.0 and as high as 4.0 in normal people, for example. An abnormal test result for potassium, then, is one whose value is greater than the highest in the range of values in normal people. But, the greater the potassium level, the more the diagnostic and treatment decisions may vary. In tesing, the magnitude of the result matters.
A key concept in testing is that the value of any test result may vary. The more abnormal it is, the more information it “contains” in terms of making a diagnosis. This may seem self evident, but failing to consider the absolute value of a test result is a common cause of missing the correct diagnosis in my experience.Continue reading…
You’ve probably seen by now both that the WSJ’s John Carreyrou has run a well researched hit piece on Theranos and that the company, led by wunderkind Elizabeth Holmes, has somewhat muffed its reply. If you haven’t, best thing is to read the Roger Parloff Fortune piece which summarizes the pay-walled piece so you don’t have to do the painful task of sending Rupert Murdoch money. Now in the spirit of FD I need to let you know that we’ve invited Holmes to speak at Health 2.0 twice and her PR handlers have been unbelievably hard to communicate with. They’ve either flat out ignored us or taken forever to turn us down, even though she’s appeared often at (what I at least consider) much less important or relevant venues. I have no idea if she’s badly advised, wanting to stay away from sophisticated health tech audiences, or if her handlers decided that we and our 2,000 strong crowd are just not cool enough for her. Or maybe simply her calendar hasn’t allowed it. Either way I have no first hand knowledge of her or the product–although Elizabeth our invite is still out there! But I do know five things.
1) Lab business decentralizes & democratizes. Whether or not Theranos is lying, cheating, not using its own tech, or its cool stuff just doesn’t work, the trend towards comprehensive, cheap and soon at home lab testing is clear. More than 5 years ago a company called BioIQ was selling at home fingerstick based cholesterol & glucose tests. In the past year the two stage Nokia Sensing XCHALLENGE (of which we hosted stage 1 at Health 2.0 in 2013) has revealed a plethora of companies taking minute quantities of blood, pee or spit and doing complex diagnosis from them. And it’s not stopping there. The next phase is using light and other sensors to diagnose direct from the skin. Whether or not the locus of activity ends up using Theranos at Walgreens or the kitchen table using something else, the dam holding back continuous, cheap multi-faceted testing is going to burst soon.
2) Theranos and Holmes are not the most important thing in health care. There, I’ve said it. While Holmes has talked a lot about revolutionizing health care access and has given lots of transparency into Theranos’ pricing if not its testing technology, what they’re up to is getting easier access to lab tests. I think this is very important and a very good thing, but no one can seriously believe that this is the biggest change in health care. It’s part of a trend towards consumerism. But I’d argue the most important trend in health care is the redesign of chronic care management, on which we spend a shed-load more than lab testing. I may be wrong but if you insert your pet issue here, I’d bet it’s not cheaper lab testing. The media has been a tad snowed by the “youngest female billionaire” and “blonde Steve Jobs” analogies, but even if she runs the field and takes over most lab testing, it’s an incremental change not a huge revolution in health care.
The passage of the Affordable Care Act (Obamacare) and the reelection of President Obama was cause for real hope among those in pursuit of the Holy Grail in medicine: higher quality at lower cost. However, with the passage of what is called the Breast Density Bill in several states, the quality cost equation seems doomed on both ends. The Affordable Care Act mandates coverage of screening mammograms, without co-pay or deductible, but the Breast Density Bill is destined to push utilization of “non-beneficial” imaging, ie imaging that does not clearly save lives, even further.
The new law, authored by Sen. Joe Simitian, was signed into law this past October in California. Beginning April of next year, the bill requires facilities that perform mammograms to include a special notice, within the imaging report sent to patients, regarding the high density of breast tissue and the benefit of additional screening tests. The notice will state the following; “Because your mammogram demonstrates that you have dense breast tissue, which could hide small abnormalities, you might benefit from supplementary screening tests, depending on your individual risk factors”.
The supporters of the bill make the ethical argument that women have the right to know about how dense breast tissue can obscure mammogram visualization, and should be offered additional test such as ultrasound and magnetic resonance imaging (MRI) to alleviate the doubt. To provide further support, the SOMO INSIGHT Breast Cancer Screening Study is a nationwide research effort to evaluate if automated breast ultrasound done together with routine screening mammogram is more accurate in detecting breast cancer in women with dense breast tissue. The study is funded by U-Systems, Inc.; the Silicon Valley based company responsible for the sophisticated and expensive ultrasound technology used in this study. Thus, one cannot deny the possibility of patient interest being confounded by financial interest.
The patient advocacy movement around breast cancer has been championed by several well-known non-profits, such as Susan B Komen, Are You Dense Inc. and even endorsement by the National Football League. Yet, the confusion about screening is reflected in the variability of requirements for insurance coverage between states. For example, while Texas and Mississippi require screening mammograms to be covered for all women 35 and older, Utah has no coverage requirement and several other states do not require coverage until age 40.1 Awareness of breast cancer screening is necessary, and the complexities of picking up certain irregularities certainly deserve attention. However, the patient’s “right to know” should also include the right to know about “over-diagnosis”.