Med thumb shutterstock 229758175

Wearable devices, like Fitbits and Jawbone bracelets, make it easy to collect data about our bodies and the physiological processes whirring inside them. In recent years, sleep-tracking has joined step-counting and calorie-counting as a popular form of self-quantification — it's estimated that 10 percent of American adults already use smart technology to keep tabs on their shuteye and that 50 percent are open to the idea.

Sleep-tracking might seem like the sort of health-conscious behavior that any doctor would applaud. But it actually gets mixed reviews from sleep bigwigs. In a case report published earlier this year, researchers at Rush University and Northwestern University argued that sleep-tracking can cause people to fixate on data that ultimately isn't that meaningful. They also came up with a name for this counterproductive obsession with sleep stats: orthosomnia. Why? Because the "perfectionist quest to achieve perfect sleep is similar to the unhealthy preoccupation with healthy eating, termed orthorexia." 

The paper detailed the experiences of three people who went to a sleep clinic because their sleep trackers said they were under-slept. The process of diagnosing and treating these patients' perceived sleep disorders revealed an unwavering loyalty to DIY data. For instance, they trusted their sleep-trackers over polysomnography, the "gold standard" in clinical-grade sleep testing.

Polysomnography, which distinguishes between different sleep stages, offers a more nuanced snapshot of sleep than consumer-grade sleep trackers. Fitbits rely on a method called actigraphy, which doesn't measure sleep per se. Instead, it uses motor activity and rest as proxies for being awake and asleep. This means that lying in bed awake can be misinterpreted as snoozing. So, for insomniacs who spend a lot of time in bed not sleeping, actigraphy may not be so reliable. 

Patients' attachment to their sleep trackers also interfered with their ability to finish Cognitive Behavioral Therapy, a non-drug treatment method for insomnia. One part of CBT(i), called sleep restriction, requires people to get out of bed when they can't sleep. The goal is to train people to associate being in bed with being asleep (and nothing else). Practicing sleep restriction often leads to a temporary reduction in sleep — it's a normal, albeit controversial, part of the treatment. But, when sleep-tracking data revealed a dip in nightly sleep duration, patients weren't inclined to stick out their 6-to-8 week course of CBT. 

Overall, patients struggled to put down their wearables and accept the limitations of their data.

Overall, the patients struggled to put down their wearables and accept the limitations of their own data. The obvious takeaway from the study is that sleep-tracking isn't a guaranteed path to understanding or improving sleep. But that doesn't mean actigraphy is useless or harmful in every context. Researchers allowed for the possibility that sleep trackers could be integrated into insomnia treatment regimens. Patients in the current study didn't succeed, but there's still hope for "other patients who are less persistent in their beliefs."

Sleep-tracking comes with pros and cons, just like most endeavors in the quantified self. Consider, for example, the protracted debate over 23andMe and other genome sequencing services. Banking millions of saliva samples has been a boon to population genetics. But, at some point, 23andMe faced criticism for overstating the clinical significance of direct-to-consumer genetic testing. 

So, where does that leave people who are flirting with the idea of tracking their sleep (and not looking to visit a sleep clinic)? Well, based on this paper and my conversations with experts, sleep-tracking poses the least risk, and potentially the greatest benefit, if:

1) You're really curious. And you can learn information about yourself without imposing undue meaning on it. 
2) Your sleep habits aren't up to snuff and daily sleep-tracker reports will give you the push you need to pause Netflix and hit the sack at a reasonable hour. But, if you can see yourself slipping into orthosomnia, find a plan b.

I'm all for learning information about myself — at least, when I think the information will please me or won't matter to me. I assume a lot of people have a similarly flawed relationship with self-discovery. As for tracking my sleep? Pass. Numbers that don't matter seem like an easy thing to obsess over. And obsession is the ultimate upper.