Q&A: Advantages, pitfalls of sleep-monitoring apps, trackers

Key takeaways:

• Sleep monitoring has been made easy with fitness trackers and apps.
• Data from this technology is useful, but clinicians must put the patient and their health issues at the forefront when helping them.

In September, Apple received marketing clearance from the FDA for its sleep apnea feature within the Health app on the Apple Watch Series 9, Series 10 and Ultra 2, according to an FDA press release.

Using wrist movement data captured via the watch’s sensor when the user is asleep, this feature/software finds patterns of breathing disturbances that could be moderate to severe sleep apnea in adults, according to releases from the FDA and Apple.

Apple reports that users are alerted if signs of sleep apnea (high breathing disturbance values in 50% of sleep recordings) are found during a data analysis that takes place every 30 days, after which, they receive several pieces of information:

• time period of possible sleep apnea;
• educational materials highlighting why seeking treatment is important; and
• a PDF that includes breathing disturbance data from 3 months, notification details and “additional information to reference during a conversation with a health care provider.”

In the study covering the design, testing and validation process for this feature, Apple noted that the algorithm needs a minimum of 10 sleep recordings in a 30-day period to make a judgement on whether signs of sleep apnea are present.

Notably, researchers behind the sleep apnea notification algorithm used 3,936 nights of at-home and in-lab polysomnography recordings (n = 2,160; mean age, 49.1 years; 53% women; 70.7% white; mean BMI, 29.6 kg/m²) for design, 7,220 nights of recordings (n = 2,542; mean age, 48.7 years; 50% women; 69.1% white; mean BMI, 29.4 kg/m²) for testing and 24 nights (n = 1,499; mean age, 46 years; 56.5% women; mean BMI, 32 kg/m²) for validation.

During validation, the sleep apnea feature achieved 66.3% weighted overall sensitivity and 98.5% weighted overall specificity, according to the study. When divided based on severity, researchers found greater sensitivity in the severe vs. moderate category (89.1% vs. 43.4%). For specificity, values were elevated in both the normal category (100%) and the mild category (91%).

Importantly, the FDA states that this feature “is not intended to diagnose, treat or aid in the management of sleep apnea” in the clearance message.

To learn more about sleep tracking/monitoring apps and how Apple’s system is perceived by sleep clinicians, Healio spoke with Seema Khosla, MD, FCCP, FAASM, American Academy of Sleep Medicine (AASM) spokesperson and medical director of the North Dakota Center for Sleep.

Healio: How prevalent are sleep tracking/monitoring apps? Has there been a rise in their use over recent years? If so, why?

Khosla: There has been a shift in our prioritization of sleep. In the past, it was common to dismiss the importance of sleep. People would routinely forego sleep in favor of something else — more practice, more studying, more socializing. We are seeing a shift in the collective mindset — it has become more acceptable to prioritize sleep.

Social media influencers evangelize on the importance of sleep as they highlight their new bedding, eye masks and lavender sprays. Fitness trackers are ubiquitous and most have a sleep metric — monitoring the timing, duration and often the quality of sleep. As technology advances and these trackers become less expensive and more aesthetically pleasing and communities grow around each device, abnormal values spill over into a sleep clinic.

Sleep technology conversations are routinely part of a sleep clinic visit with patients and clinicians reviewing tracker-generated reports while trying to fit the results into the context of clinical symptoms.

Healio: How accurate are these apps?

Khosla: Undoubtedly, the technology has been improving with every iteration. While we are not yet at the point where these would replace traditional in-lab or home sleep apnea tests, they certainly have become more sophisticated. Rather than viewing these as competitors, perhaps we should consider how these devices may supplement the patient history or alert the user to the possibility of a yet undiagnosed sleep disorder such as obstructive sleep apnea. This may prompt a clinical evaluation earlier and may ultimately improve the sleep health of our communities.

Healio: Do these apps offer doctors any clinical value in treatment of sleep disorders?

Khosla: Sleep tracking apps give users useful information about their sleep patterns and potential issues, which can help doctors understand their patient’s sleep quality and spot any trends using data. Apps can also flag signs of something like sleep apnea, which may encourage users to get checked out and start a conversation with their health care provider.

In addition to potentially alerting the user to the possibility of an underlying sleep disorder, they may help in the management of sleep disorders, even those as common as insufficient sleep syndrome.

Healio: How does Apple’s system compare with these apps?

Khosla: This is a competitive industry, and algorithms are trade secrets making comparison difficult. There have been many attempts, including our own internal testing, to compare the various consumer-facing sleep technology such as the Apple Watch, FitBit, Garmin and many others. Updates are pushed out without necessarily understanding what those updates do. By the time we’re able to compare devices, they have often become obsolete. Keeping up with every device is untenable. Therefore, the AASM has developed guidelines for clinicians to assist with this challenge.

Even with those peer-created resources, technology improves at a cadence that far surpasses our ability to fully comprehend the nuances of each device.

Healio: The Apple system provides educational materials. How valuable is education in treatment?

Khosla: For the majority of health conditions, education is key. Understanding your own body and how various disorders affect your mind or body is fundamental, especially when a new technology is deployed. The end user needs to understand not only what their device is telling them but what to do with that information.

Healio: The Apple system also provides 3 months of breathing disturbance data. How much value does this data have?

Khosla: We know that our sleep is not exactly the same every single night. We may snore when we have a cold or consume alcohol, for example. We may be worried about something and not sleep as well on some nights. By capturing multiple nights of data, we begin to get a sense of the overall picture. Some patterns may emerge that point us in one direction instead of another.

We also need to remember not to get carried away by the numbers — we need to take a step back and look at the person behind the data. Do they fit with the clinical signs and symptoms? In medicine, we must remember to treat the human being and not just the numbers. The data should be one consideration, but the patient and their health issues should guide the discussion.

Healio: Apple says the system provides users with information to discuss with their health care providers. Do you see value in this information?

Khosla: There’s definitely value in having information to share with health care providers. When users bring data to their doctors — whether it’s about sleep patterns, breathing disturbances or other health metrics — it gives us more insight into what’s going on between visits. It also helps make conversations more focused and productive, since we can use that information to make better recommendations or decide if further tests are needed.

Healio: Are there factors that the Apple Watch feature fails to provide that would assist clinicians?

Khosla: It’s probably a bit early to tell. Once we start to see patients in clinic and review their sleep technology information with them, we will likely start to get a sense of which data point we might like to see — such as an oxygen level, for example.

Part of this will depend upon our clinical experience when we do evidence-based testing and compare those results with the data obtained by the consumer wearable. The more we see it, the more we will understand how important (or unimportant) those metrics may be.

Healio: What would you advise patients who suspect they have sleep apnea who are interested in this or other devices?

Khosla: If someone has signs or symptoms of a sleep disorder, they should see a health care professional and discuss those concerns. There is no need to wait and collect more data — the symptoms are enough to warrant further assessment.

If they happen to have a tracker that notifies them of a potential issue, they can certainly bring that information with them to their health care professional. We don’t want to lose sight of what really matters, the human behind the data.

It is also extremely important to remember that these devices may notify you if something is not right, but if your device is quiet and doesn’t notify you of an issue, you can’t rule it out. Please don’t rely on consumer technology to tell you when you have an issue — if you think you may have a sleep disorder, please have it evaluated even if your sleep score is excellent. We would rather have you feel great with a bad sleep score than have you feel terrible with a perfect sleep score — the person is more important than the algorithm.

Additionally, while these new features are certainly exciting, we still need to make sure we are covering the basics — adults should obtain between 7 to 9 hours of sleep every night, a consistent bedtime and rise time are important and we need to create a sleep environment that makes us feel safe, comfortable and ready for sleep.

References:

• FDA roundup: September 17, 2024. https://www.fda.gov/news-events/press-announcements/fda-roundup-september-17-2024. Published Sept. 17, 2024. Accessed Sept. 17, 2024.
• Estimating breathing disturbances and sleep apnea risk from Apple Watch. https://www.apple.com/health/pdf/sleep-apnea/Sleep_Apnea_Notifications_on_Apple_Watch_September_2024.pdf. Published September 2024. Accessed Sept. 27, 2024.
• watchOS 11 is available today. https://www.apple.com/newsroom/2024/09/watchos-11-is-available-today/. Published Sept. 16, 2024. Accessed Sept. 18, 2024.