More data does not mean more over-treatment (in the long run)

Whenever I read articles about new methods of gathering health information (such as frequent blood work, imaging, or other sensor data), one of the most common responses is that with this data we risk massive over-diagnosis and over-treatment of patients.

This isn’t just a straw man argument to beat up, thats an exact quote from a hacker news discussion, and its one I’ve seen brought up many times by doctors in quantified self related articles.

I appreciate the systemic concern around these things, because they represent truths on the ground right now. Yet every time I see this response, I see it as incredibly short-sighted. Its yesterday’s thinking projected into the future.

Today’s Mis-Match of Patients and Medicine

Over-diagnosis and over-treatment is a concern based on real experiences and systemic struggles felt today. Increasingly, patients are coming in armed with DNA results, heart rate data, or just things they heard and symptoms that they looked up, leading to the common refrain ‘with google, everyone is a doctor’. Unfortunately what these patients want is fundamentally incompatible with today’s way of doing medicine.

Our present system is a hydra of many models and approaches, so its hard to reduce it down to one thing, but I think its fair to say today’s medicine is a rather blunt instrument. It only intervenes when things are generally pretty bad for patients. It operates on a ‘trust us, we’re experts’ model. It even (generally) presumes everyone’s decently healthy, otherwise they’d be in a hospital. Medicine most often ends the moment the patient steps outside the hospital.


Just as our medical system is reactive to sickness rather than proactive with preventative medicine, so too is its approach to information. Doctors must react to patients misunderstandings of what they read or what test result they have, rather than having a proactive system provide information services that help patients live healthier lives and grapple with medical issues.

This experience is incredibly unsatisfying and often sub-optimal for patients wishing to take control of their well-being. We live in a world where answers are a query away, so its natural that when we’re not feeling well, we seek answers rather than ignore our symptoms or trust what the doctor said in the few minutes they saw us.

Unfortunately looking for medical information online is almost a fool’s errand. Either you get highly generic information that leads you to think your symptoms are some horrible disease, or you find specific information followed by terrible advice in some sort of blind-leading-the-blind forum. Nevertheless, many ill-informed patients gain confidence in their new found ‘expertise’ and begin to distrust doctors, as the medical system isn’t providing them adequate peace of mind in the age of information.

today, Data is for sick people

Medical information and patient data are two sides of the same coin, yet they rarely intersect in a meaningful way for patients. Most health data today is in the form of bloodwork or imaging that we barely have access to. We generally get it only when we’re sick. Because people aren’t sick too often, the data tends to be sparse, and doctor interpretation really matters. This interpretation is costly because that sparseness means the data is rather inaccurate, and expertise is the best way to improve that accuracy.

Because we have so few data points, we actually have little idea about the natural rhythms and individual differences of any one person. Instead, we have this really static view of all aspects of our bodies, coupled with very broad ‘normal’ ranges – the blunt instrument of medicine applied to data. Given this context, if we choose to do a bunch of tests on a perfectly healthy person, it’s highly likely something will be outside normal. Applying todays thinking, that’s a patient over-diagnosis problem, and could lead to over-treatment, so we don’t do it.

The counter-intuitive nature of ‘less data is better’ is not lost on patients, and many have sought to better understand their health through DNA kits, nutrition and activity tracking, heart rate and blood pressure monitors, and many other sources. Meanwhile the medical system itself has no idea what to do with data that is not directly related to sick people. They view this patient data skeptically, and, because they bear the costs of servicing inquisitive patients, simply worry about over-diagnosis.

Yet Data from healthy people means less sick people

The whole process of diagnosis can change though. If we gathered more frequent bloodwork and imaging from lots of people, we’d get a better sense of the patterns and variance in every individual – the dynamic body not the static snapshot. We’d be able to catch things earlier. We’d start to understand what normal was for the individual, rather than the mythical average person (who doesn’t exist). And with more focus on data over time, the medical system would now know what to do with patient provided data – it would act as a complement to paint a more complete picture of what was going on.

This has the potential to lower costs in three ways.

First, this acts as a way to bridge the gap between patients and doctors. With an outlet to provide their own health data, patients would feel heard and get more bought into the process, ultimately being more involved in their health. Mending the distrust between patients and doctors would mean less wasted time fielding questions about google results and patients more likely to follow care plans their doctors give them.

Second, this data would bring greater accuracy in diagnosis. This can lead to a lower cost structure because interpretation could be more broadly distributed among healthcare workers and automated systems, rather than always requiring the expertise of a doctor.

Third, this data would greatly enhance preventative medicine. Instead of being overly concerned when one of our tests goes outside the normal range, as we would today, we’ll be used to this. Normal ranges themselves will change to normal for us ranges. These data might result in health care providers recommending some minor preventative medicine course-correction instead of being unaware of a condition until it reached a sufficiently bad point.

Its the getting there that is hard

This is why the medical system should be working today to move from the doctor-centric, data-when-necessary model to a data early, data often model. With enough data, we’ll have much better ability to understand when something is truly problematic that requires expensive & risky treatment. In that respect, frequent testing can lead to less expensive/risky over-treatment than today’s world of infrequent sampling, and more cheap/minor nutritional/activity/etc interventions backed by data.

I think the concern behind statements about more data leading to over-diagnosis is that the current system isn’t going to be able to easily adapt to this new approach. I’d definitely agree – in the meantime there’s going to be some over-diagnosis until the medical system can wrap its head around a new data-rich approach to things. There was even some over-diagnosis in my recent past, due to poor medical information.

I’ve had to deal a lot with medical data the past year and a half. I learned just how bad the state of medical information is online, and I could see how it would change a patient’s relationship with their doctor. Yet I’m lucky enough to have had enough education and time to empower myself to be a better patient. I kept myself informed enough to have significant insight into what I was dealing with. I got my bloodwork history going back a decade which allowed me to understand what my normal was and how concerned I should be about any particular result. And I logged all my physical activity, tracked medications, and wrote health journals, which let me understand my symptoms, find causality, and optimize treatment. I believe overall my experience is a crudely hacked together glimpse into what a future patient experience could be.