Sleep that knits up the ravelled sleeve of care
The death of each day’s life, sore labour’s bath
Balm of hurt minds, great nature’s second course,
Chief nourisher in life’s feast.
–William Shakespeare, Macbeth
The company that makes the Zeo Personal Sleep Coach kindly sent me one of their devices to try out. It’s a nifty little gadget, and if you are a techno geek, you would probably love it. It’s a fascinating toy; but for insomnia, there’s no evidence that it provides any benefit over standard treatment with sleep logs and sleep hygiene advice.
Polysomnography is done overnight in a sleep lab and costs around $1000. It records multiple parameters: EEG, EKG, EMG, breathing, O2, CO2, and limb movements. It is most commonly used to diagnose obstructive sleep apnea (OSA), a serious condition that is linked to hypertension, heart disease, diabetes, metabolic syndrome, stroke, and increased mortality. OSA can be effectively treated with CPAP and other measures. About 50% of snorers have sleep apnea. We typically think of it as a disease of obese, loudly snoring older men, but even young children can have it: snoring is probably never normal in children and should be investigated.
The Zeo is the first sleep monitor available for consumers to use at home. It doesn’t pretend to do what polysomnography does. It can’t diagnose sleep apnea. It is billed as an educational and motivational tool, not intended for the diagnosis or treatment of sleep disorders. A unit that looks sort of like an alarm clock sits on your bedside table and communicates wirelessly with a comfortable soft elastic headband that positions embedded sensors over your forehead to pick up your brain waves.
It provides a graph of the entire night showing when you were awake, in light sleep, deep sleep and REM sleep. It gives a readout of how many minutes you were in each stage and how that compares to your average readings. Most importantly, it gives a ZQ score: a single number that adds the “good sleep” numbers and subtracts the awakenings to provide a single score that you can use to compare your sleep quality from night to night and to compare your sleep to that of the average person of your age.
The information can be uploaded to the Internet and viewed on the company’s website. It is then used to provide individualized coaching. A lifetime of coaching is included in the purchase price of $349, or you can buy the product without coaching for $249 and can add coaching for $7.95/month or $79.95/year.
Normal sleep architecture:
- We should not fall asleep the moment our head hits the pillow: that indicates a sleep deficit. It normally takes 20 minutes or so to get to sleep.
- REM (Rapid Eye Movement): 20-25% of total sleep time. Normally absent during the first 90 minutes of sleep and then occurs about every 90 minutes. Was thought to be the stage where dreams occur, but now we know dreams occur in every stage of sleep.
- NREM (Non-Rapid Eye Movement): 75-80% of total sleep time. Includes light sleep and deep sleep.
- Awakenings during the night are normal and more common as we age. We don’t remember awakenings that last less than a minute. The Zeo registers awakenings that last at least 2 minutes.
According to the manufacturer, two scientifically controlled studies have compared the Zeo’s sleep stage readings to polysomnography readings and found them valid. But how useful is it to know this information? We don’t know what the optimal time in each stage is, and we don’t yet know how to increase REM sleep even if we wanted to. One uncontrolled pre-marketing study found that home users reported significant improvements in the quality of their sleep and better functioning in the daytime, but with no control group these results are uninterpretable.
The ZQ score is an arbitrarily constructed score that has not been validated. If your score goes up 10 points are you really sleeping better? Is it a useful measurement? It is handy in one sense: my husband used to ask me if I slept well, and I would answer “yes” or “no” or “fairly well I guess.” Now I can tell him “68” or “93.” I can see a downside: it would be easy to become psychologically dependent on these numbers and obsess if your score went down. I lent my machine to a friend to try, and immediately found myself missing it. I had come to look forward to seeing my ZQ report every morning.
I chose not to try the online sleep coaching because I thought I could do my own coaching. It’s not hard to read about sleep hygiene measures and apply them, to notice whether the ZQ score goes down if you drink coffee in the evening, etc.
Zeo offers another intriguing service. You can set the alarm and ask it to wake you up to half an hour earlier, picking a time that you are in the stage of sleep that is easiest to awaken from, so you are not violently jolted awake from a deep sleep. I don’t use an alarm (I’m retired and have the luxury of sleeping until I wake naturally) so I didn’t get to try this function out. I don’t know if the benefits of gentle awakening would outweigh the harm of being awakened up to half an hour early and having total sleep time reduced.
Insomnia is a common problem and sleeping pills are not the answer. Insomnia can be treated effectively by cognitive behavioral therapy (CBT): it works to some extent in almost all patients, and has long-term success. It involves counseling in sleep hygiene, cognitive therapy and stimulus control therapy, and when necessary, sleep restriction therapy. It corrects misunderstandings about normal sleep, establishes realistic expectations, and uses simple relaxation techniques and measures like establishing regular sleep hours and a quiet 30-to-60 minute pre-bedtime routine, avoiding caffeine and alcohol, getting out of bed when you can’t sleep, using the bed only for sleep and sex, exercising during the day but not close to bedtime, keeping the bedroom quiet and at a comfortable temperature, banishing pets from the bedroom, addressing stress issues. Patients are instructed to keep a sleep diary, recording how long they slept, how often they woke up during the night, how refreshed they felt in the morning, whether any factors disturbed their sleep, when they exercised, when they drank coffee or alcohol, etc. It’s hard to see how the Zeo could add anything important to this approach except as a crutch to help motivate patients who are not initially cooperative. What I would like to see is a controlled study comparing optimum sleep hygiene and cognitive behavioral therapy to the use of a Zeo and online sleep coaching. One problem would be picking a reliable measure of sleep improvement to assess outcomes.
The Zeo program might turn out to be the best initial approach to insomnia, since it is less expensive than multiple office visits with a provider for CBT. But I wonder if a web-based program providing the same information about sleep hygiene and giving feedback and encouragement might be just as effective without the device. Pending controlled studies, I will have to assume that it is just a gimmick to enlist patients in doing what they should be doing anyway.
Note: My source for the information about normal sleep, sleep apnea, and treatment of insomnia was a CME course on sleep disorders that I attended in Seattle on Feb. 20, 2010, sponsored by the AAFP in conjunction with the American College of Chest Physicians and presented by a panel of experts in sleep disorders.
This article was originally published in the Science-Based Medicine Blog.