The Case for Actigraphy in Pediatric Research and Clinical Practice

Don’t throw the baby out with the bath water.

That was my response on a recent panel discussion about the future of actigraphy and consumer wearables. The panel formed because one of the major producers of actigraphs announced (out of the blue) that they were discontinuing their devices. With the known limitations of actigraphy, and the rapid advancements in consumer wearables, the panel was asked whether it was time to abandon actigraphy altogether.

While I do see the value in consumer wearables, and I am hopeful about the future use of these devices for research and clinical practice, it is not yet time to abandon actigraphy, especially in pediatrics.

Over my 20+ year career I have spent a significant amount of time working to make pediatric actigraphy more standardized for research, with studies examining device validation, scoring rules, and norms for children and adolescents. I have also demonstrated the clinical utility of these devices.

To help researchers and clinicians consider the role of actigraphy in their work, this blog will provide an overview of the strengths and limitations of these devices, and why they remain a better choice than current consumer wearables. Specifically I will provide a high level overview of:

• What is actigraphy?

• The utility of actigraphy in pediatric research

• The utility of actigraphy in pediatric clinical care

What is Actigraphy?

Actigraphy is an ambulatory study used to estimate sleep-wake patterns with a wrist-watch sized device (an actigraph). These devices have different types of accelerometers, and estimate sleep with the premise that movements are frequent and large during wakefulness, but absent or small during sleep. In this blog, actigraphs refer to FDA-cleared, medical grade devices.

The actigraph device is typically placed on the non-dominant wrist (or on the ankle of children under 3 years), and worn 24-hours a day for 1-2 weeks. Using device specific software and algorithms that have been validated again PSG, each minute is identified as “sleep” or “wake.” Ideally, a sleep diary is also provided to help with the scoring of sleep periods (reported bedtime to wake time), with event markers (a button that can be pushed to also report bedtime and wake time) and light sensors also used to interpret the data seen in the actigram (example below).

As discussed in a previous blog, compared to the gold standard PSG, actigraphy is a useful tool to capture multiple nights of sleep duration, sleep timing, and sleep efficiency in a person’s natural sleep environment.

However, because these devices primarily use a single channel of data, in this case movement, actigraphy is not without limitations. In children, who are known to be restless sleepers, actigraphy can underestimate sleep duration. While in adolescents and adults, motionless wakefulness, or lying still for long periods while awake, can result in an overestimation of sleep duration.

Consumer wearables (e.g., Fitbit, Oura, Garmin, Apple Watch, etc.) also estimate sleep-wake patterns through movement. However, some devices also use other channels of data, such as heart rate variability. Notably, these devices are not designed for children and adolescents, and no consumer wearable device has received FDA clearance for sleep. Some devices have been validated against PSG, with a limited number of studies in pediatrics. The rapid evolution of the devices raise questions about the validity of each new device. Scoring algorithms are proprietary, and can be changed at the whim of the manufacturer. Consumer wearables are prone to the same limitations of over and underestimating sleep duration as pediatric actigraphy.

The Actigram

Once actigraphy data are scored, the software provides an actigram, or pictorial version of the data, as well as data, including means, ranges, and other descriptive information requested by the user.

A quick tour of the actigram you see above. Each line is a day of the week, starting with Thursday. Each day starts at noon (the time is the X-axis) with midnight in the middle. The vertical black lines represent activity. The thin yellow line is a light sensor. The thin pink line is a temperature sensor (which assists with telling when the device has been removed), and the thick pink line is when the device was actually off. The blue triangles are when the patient pushed the event marker button, and the shaded aqua area is the manually scored sleep period. The red underlines are when the software scored sleep.

Without even seeing the data you can quickly guess this is an adolescent who gets insufficient sleep on weekdays, and then significant oversleep on weekends. Notably, she was also sick during the first few nights of this study, and you can see increased activity during sleep and a long nap on Saturday afternoon.

But it is not just a pretty picture. Because data are generated in an exportable format (e.g., csv) we can calculate means, night-to-night variability, or examine differences between weekdays and weekends. For example, while the overall average wake time of this teen was 7:49am and sleep duration was 7.5 hours, I was able to calculate averages for the five weekdays, with a wake time of 6:15am and a sleep duration of only 6.4 hours.

Consumer wearables typically only provide summary variables for the past week or month, and may offer pictures of individual nights of sleep. However, they do not provide the ability to visualize 1-2 weeks of detailed data, nor can you easily extract data in an analyzable format for most devices.

The Utility of Actigraphy in Pediatric Research

Unless your goal is to detect a sleep disorder, such as obstructive sleep apnea, actigraphy is the best objective assessment of pediatric sleep. Not only does it allow for multi-night assessment, but collects data in the participant’s familiar sleep environment.

Actigraphy can be used in pediatric research to:

• Measure sleep as an outcome, including sleep duration, sleep timing, and sleep efficiency (three main aspects of pediatric sleep health)

• Monitor adherence to a study protocol

• Compare sleep outcomes before and after an intervention

• Evaluate circadian sleep-activity rhythms

Study Protocol Adherence

Here is an example of using actigraphy to monitor adherence to a study protocol. In this case, adolescent participants were asked to have a short sleep opportunity for five nights (6.5 hours in bed, left actigram), a weekend washout, and a healthy sleep opportunity for five nights (9.5 hours in bed, same participant, right actigram).

Pre and Post Treatment

Here is an example of monitoring sleep before and after intensive treatment for severe eczema in a 10 year old child. In the post-treatment actigram (right side), he had fewer prolonged night wakings. But the extracted data were even more impressive, with his sleep duration improving from 5.1 to 7.6 hours and his sleep efficiency improving from 55 to 79%.

Consumer wearables are an appealing choice for research due to their lower cost. However, the ability to extract usable data, along with concerns about manufacturers changing scoring algorithms in the middle of your study, continue to make these devices less suitable. New software programs are being developed to address the data extraction concerns. However, if you choose to use these devices in research, it is critical that you partner with the device manufacturer to ensure that the scoring algorithm is not changed mid-study.

The Utility of Actigraphy in Pediatric Clinical Care

Actigraphy is recommended in the International Classification of Sleep Disorders - 3rd Edition (ICSD-3), and by the American Academy of Sleep Medicine, to assist with the diagnosis of the following disorders:

• Insomnia

• Narcolepsy (not as a diagnostic tool, but to ensure sufficient sleep duration coming into an MSLT)

• Circadian rhythm sleep-wake phase disorders (in particular delayed sleep-wake phase disorder in adolescents)

• Insufficient sleep syndrome

This article reviews several examples of clinical cases where actigraphy was utilized in pediatric care.

Case Example - Poor Historian

In addition to using actigraphy for diagnostic purposes and treatment monitoring, actigraphy is useful in clinical care when you have poor historians (parent and/or child). The above example was an 18 year old who reported sleeping 16-18 hours a day. In this actigram you can see he did in fact have several prolonged sleep periods, however, he also had several very short sleep periods (mean sleep periods: 9.7 hours, range: 2.3 to 14.3 hours). Notably, he also had prolonged wakeful periods (mean hours of wake: 14.7 hours, range: 1.4 to 31.7 hours). In fact, he had 6 days of being awake at least 21 hours, and 3 days of being awake at least 24 hours. This is different than what was reported in clinic and changed the approach to treatment.

CPT and Billing

The CPT code for actigraphy is 95803, and is defined as “testing, recording, analysis, interpretation, and report (minimum of 72 hours to 14 consecutive days of recording)”. Unfortunately, most private insurance companies will not reimburse for actigraphy, despite years of lobbying efforts and attempts to provide standardized guidance. However, there are several different models for how to charge for actigraphy services to ensure some type of payment/reimbursement for this important service.

Consumer wearables have the same limitations for clinical practice as for research, including the challenge of visualizing data and extracting data for analyses. That said, if a patient comes in with wearable data, take a look! As described in this blog, wearables can be very useful as a sleep diary!!

Need Assistance with Actigraphy?

The goal of this high level summary was to show how actigraphy remains important for pediatric sleep research and clinical care.

Nyxeos Consulting can assist with your actigraphy needs, including:

• Switching brands of actigraphy devices

• Scoring research actigraphy studies

• Integrating actigraphy into research

• Creating a clinical actigraphy program

• Assisting with clinical scoring and interpretation

Learn more about our actigraphy services or schedule your free consultation today!