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“Every Breath You Take, Every Move You Make…” How Much Monitoring Is Too Much?

The views expressed are those of the author and are not necessarily those of Scientific American.

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It started in the ‘70s. A pregnant woman with diabetes faced a deeply entrenched medical routine: months in hospital having her blood glucose closely monitored. She managed to stay out by convincing her doctor, Clara Lowy, [1] to let her monitor her own glucose levels. Around that time others had been starting down the road of combining wearable sensors [2] with wearable computing.

Since then, medical self-monitoring has galloped along. And somewhere along the line, using sensors feeding data into computers became a normal part of life for high-performance athletes. Now, many of our friends are clocking their every step. There are people using apps to monitor their sleep, food, weight, heart-rate and moods – and even some people without diabetes are buying blood glucose monitors.

If the enthusiasts of the ‘quantified self’ movement [3] are right, this mash-up of health, fitness, gadget and data-crunching crazes is just the beginning of a very big wave that will carry most of us along. [4] And they rather fervently believe that the more people juggling more data, the better. [5] We’ll prevent illness, identify the causes of any ills or irritations we do have by constant cross-analysis of our very own big data, and generally hit any number of health and fitness targets. What could possibly go wrong?

Professor Paul Glasziou, author of Evidence-Based Medical Monitoring, [6] is taking stock this week at Evidence Live [7] in Oxford. Medicine has come a long way since Clara Lowy’s first foray with a patient monitoring her own blood glucose. Glasziou pointed out that billions are now spent annually on blood glucose monitoring. And while it’s valuable for people with diabetes that are pregnant and/or using insulin, it isn’t going to improve the health of those who don’t use insulin. [8]

Glasziou stressed the harm caused from acting on random within-person variations. For monitoring to be effective, he said you need 3 elements:

  • Valid and accurate measurement,
  • Informed interpretation and
  • Effective action that can be taken in response.

And you need evidence to show that a monitoring regime does more good than harm.

How valid and accurate are the tracking devices for healthy people? It’s clear that even the basic ones still have a long way to go on this score. [9] Using two trackers on the same day yielded a count of 7,116 steps from one device and 2,192 steps for one enthusiast who conceded this isn’t yet going the way you’d like. [4]

Whichever pedometer is used though, there’s an underlying problem in the assumption that they will improve health. Pedometers may help you walk more when you start using them, but improvement hasn’t been solidly sustained over time. [10] The same problem may hamper the hopes people have for benefiting from monitoring their weight. [11]

Glasziou’s informed interpretation requirement is another big problem with relying on analyses from big data. There are major pitfalls in acting on random variations and the results of multiple testing. [12] With large datasets, a great deal that may not be important could appear to be “significant”. [13]

What’s more, we are still by no means as well-informed about truly helpful targets for the healthy as many appear to think. [14] Human health isn’t about simple mechanics and tinkering with a few measurable levels.

All this skepticism doesn’t mean that I believe this is all a waste of time. Far from it. There will no doubt be ways that monitoring and monitoring technologies will help many people. There is, though, potential for harm, including unnecessary and pointless anxiety.

There’s value, too, in contemplating the meaning of where we’re going with this, and the consequences of adults focusing so much on our selves in this particular way.

When Clara Lowy’s patient turned to self-monitoring, it was to gain some freedom from medicalization. Self-monitoring still provides that freedom and indeed empowerment for many people with chronic diseases.

But as it encroaches on the healthy, monitoring becomes a beachhead in the medicalization of our lives, and maybe even how we view our selves and what constitutes a life well lived. Socrates spoke of the examined life being the only kind worth living for a human being: [16] he wasn’t expressing a belief in self-improvement from turning our attention ever more to the minutiae of our bodies.


Footnote: Pew Internet researchers [17] estimate that 1 in 5 Americans is using some kind of computer technology to “self-track” their health.

Image: copyright by author.

Hilda Bastian About the Author: Hilda Bastian likes thinking about bias, uncertainty and how we come to know all sorts of thing. Her day job is making clinical effectiveness research accessible. And she explores the limitless comedic potential of clinical epidemiology at her cartoon blog, Statistically Funny. Follow on Twitter @hildabast.

The views expressed are those of the author and are not necessarily those of Scientific American.

Comments 3 Comments

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  1. 1. Carolyn Thomas 5:31 pm 03/25/2013

    Lovely job here, Hilda, in helping to whittle a complex topic down to common sense-ical size. Thank you for this! And a belated thank you for your delightful cartoons which I’ve been enjoying, too.

    As one sage succinctly put it while we were attending Stanford University’s Medicine X conference last fall:

    “Why do we think self-tracking devices will work when mirrors and bathroom scales have so far failed?”

    The third element you mentioned here that’s necessary for monitoring to be effective – “Effective action that can be taken in response” – is often overlooked by the tech hypemeisters who are busy high-fiving each other while developing the Next Big Thing.

    Just this week, I was drawn into lively online discussions about the unanticipated dilemma of using heart monitor technology that produces results doctors aren’t quite ready to act upon. Fire captain/paramedic/blogger Tom Bouthillet pointed out, for example: “AngelMed devices can detect heart attacks so early, clinicians aren’t sure what to do about it. Do you cath them? Do you wait for the surface ECG to show STEMI and then cath them?” You may have collected more data, but data alone won’t necessarily drive reactions to data.

    One Quantified Selfer I met at Stanford told me he’d been monitoring his stress levels by tracking his pulse/blood pressure 24/7 for four years, synched with his Outlook calendar so that he can always tell exactly which activities are most stressful. His 4-year results: being in rush-hour traffic and sitting in meetings caused him the most stress. (I could have told him that for free and saved him four years of tracking…)

    Again, back to your point #3: what “effective action” is this guy planning to do as a result of four years worth of tracking? Stop working?!

    If tracking isn’t tied to some kind of measurable action, it’s merely self-obsession. More on this at: “Does Knowing Change Behaving?” –

    Link to this
  2. 2. HildaBast 7:40 am 03/26/2013

    Thanks, Carolyn! Really like the mirror quote: and it also points to the critical issue of the potential for these things to be anxiety-provoking/depressing. Enjoyed the blog – thanks for that, too.

    Link to this
  3. 3. continuum 2:25 pm 03/26/2013

    Great post Hilda. Whether you want to call it quantified self, connected health, or wearable health – it’s definitely a space to watch. I work for Continuum, a global design and innovation consultancy, and my coworker Kevin Young was on Bloomberg TV last week discussing the growth of wearable health. Check it out:

    Link to this

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