Every few days a patient asks me if sleep apps are reliable. Others bring me data that they have gathered from their smartphone apps and want it interpreted. I have often replied that I wish these apps could be tested against the gold standard, a polysomnogram (PSG), to assess their reliability. Recently, one app called Sleep Time from Azumio, Inc. was evaluated against polysomnography in a small study from the JFK Neuroscience Institute.

Sleep Time is one of the most popular downloadable sleep apps and is marketed to provide users with information regarding different stages of sleep. The app is designed to wake users during light sleep before their alarm sounds for an easier arousal in the morning.

The Sleep Time study included participants who were medical residents, fellows, attendings, and sleep lab technicians. The subjects were tested during a full-night PSG in conjunction with using the app. The PSG hypnogram and the sleep app graph were divided into 15 minute intervals for comparison. Unfortunately, the sleep app performed poorly when compared to PSG. It did appear to be effective in being able to detect when the subjects fell asleep, but it was unable to accurately discern when users were in various stages of sleep. These results should not surprise those of us in sleep medicine, as PSGs include EEG sensors that monitor brain waves to detect when a patient is sleeping. Putting a phone next to a person’s head, at least at this point in technology, is unlikely to be able to read brainwaves.

Continue Reading

The manufacturer of the app would not disclose how their technology is supposed to work, but it is believed to be based on the typical movement-based algorithm that other sleep apps use. This is very similar to actigraphy, which is used in sleep medicine to detect movements during sleep.

Actigraphy could potentially be affected by the firmness of a mattress, movement sleep disorders such as periodic limb movements of sleep, and the bed partner’s sleep disorders. We often forget that we are affected by sleep partners. Perhaps they are the ones tossing and turning all night while the phone under your head is being jostled around. If this is the case, the patient may be getting unreliable data and trying to solve a sleep issue that isn’t even their own!

How can these apps be helpful then? Since the app appeared to be able to detect sleep latency, this can help insomnia patients that do not feel like they are getting adequate sleep. They may see that they are actually getting more sleep than they think. It can also remind patients to get more sleep, if needed. If they see they are sleeping less than 7-8 hours, they can adjust their schedule to get more sleep.

These apps, of course, state that they are not medical devices. However, consumers have expectations and sometimes believe that they are getting reliable information. This could be detrimental if the user actually has an untreated sleep disorder.

As technology improves, more sleep apps will likely be released, and patients may ask about them more frequently. If your patients have sleep complaints, be sure that you are giving these complaints adequate attention and referring them to your preferred sleep professional.

Sharon M. O’Brien, MPAS, PA-C, is a practicing clinician with an interest is helping patients understand the importance of sleep hygiene and the impact of sleep on health.


  1. Bhat S et al. J Clin Sleep Med. 2015; doi:11(7):709–715.