With all the latest news about portable monitoring for OSA, it may be easy to overlook another major technology development that will inventively affect the sleep market—actigraphy.

In the past, the American sleep community frowned upon actigraphy as being nearer to voodoo science than a valid sleep diagnostic tool. While actigraphy still has its critics for some sleep diagnostic applications such as OSA, there are clear signs of it becoming a regular—and reimbursable—tool for diagnosing insomnia and circadian rhythm disorders.

STEP 1 TO GAINING ACCEPTANCE: NEW AASM PRACTICE PARAMETERS

Actigraphy’s emergence as a part of mainstream sleep medicine is mainly due to two recent events in the last year:

First, the Standards of Practice Committee of the American Academy of Sleep Medicine (AASM) updated its actigraphy practice parameters in 2007. The new guidelines acknowledged the explosion of research in actigraphy since the committee’s previous evaluation in 2002. These new studies presented the AASM with overwhelming evidence that actigraphy can be used as an effective tool for diagnosing circadian rhythm disorders and other sleep conditions.

Specifically, the 2007 practice parameters update states that actigraphy is useful for evaluating the following:

  • Insomnia
  • Hypersomnia
  • Advanced sleep phase syndrome (ASPS)
  • Delayed sleep phase syndrome (DSPS)
  • Shift worker disorder
  • Jet lag disorder
  • Non-24-hour sleep/wake syndrome (including that associated with blindness)

In addition, the new practice parameters suggest that actigraphy may be used to estimate total sleep time in home studies when polysomnography is unavailable. It also opens the door to actigraphy usage as a means to evaluate the response to circadian rhythm therapies and determine sleep patterns.

Finally, AASM practice parameters recommend that actigraphy may be used for evaluating sleep patterns in infants and some senior citizens in nursing facilities. The report concludes by noting that additional research is warranted to further refine and broaden actigraphy’s clinical value.1

STEP 2 TO GAINING ACCEPTANCE: GETTING REIMBURSED

The second—and some might argue—the most significant development for sleep laboratories is that the American Medical Association recently cleared the way for actigraphy to be a reimbursable diagnostic test by reclassifying it as a Category I reimbursable Current Procedural Terminology (CPT) code. Previously, actigraphy was classified as an experimental (Category III) procedure, which was not reimbursable.

Together, these two actigraphy endorsements are a leap forward for actigraphy that will certainly affect both the business of sleep as well as patient care.

Lawrence J. Epstein, MD, current medical director of Sleep HealthCenters, Brighton, Mass, and past president of the AASM, says of the AMA code change, “What this means is that there’s been sufficient documentation of the usefulness of actigraphy and allows it to move from an experimental to an accepted methodology. So, for sleep centers, it means that they will now be able to use this in the evaluation of patients and sleep disorders, and hopefully be reimbursed for it.”

The AMA has yet to release the recommended reimbursement cost or any restrictions that would go along with that reimbursement. However, Epstein and other specialists in the field are cautious about predicting any windfall to sleep laboratories with the new CPT code.

Rick W. Finch, senior vice president for device manufacturer ActiGraph, LLC, Pensacola, Fla, says, “The CPT I code is going to be very valuable to everyone in the sleep world, but that’s just really the first step. The biggest determining factor that we see is what types of restrictions are placed around the code, because if it’s still difficult for physicians to prescribe the ActiGraph, they simply won’t do it.”

Mark Reed, MS, clinical consultant for Respironics, Murrysville, Pa, and a longtime researcher and advocate of actigraphy, is more optimistic about the AMA decision on sleep laboratories, especially with regard to circadian rhythm disorders and insomnia.

“You have a large number of sleep labs around the country that have not implemented the technology because they haven’t been able to utilize it and have it pay for itself,” says Reed. “So, the ability to potentially make the use of a technology and get compensated for it might really open the possibility that they will be able to more cost-effectively work with those patient groups instead of simply referring them to other places for care, like to a psychiatric professional.”

Actigraphy is currently before the AMA’s Relative Value Update Committee (RUC), which is surveying people who use the device. Committee members will eventually use the data to compare actigraphy with other established procedures and set a relative value for the technical and professional components.

The decision is expected sometime in late 2008 or early 2009, but just because actigraphy will become reimbursable to physicians, few believe that sleep laboratories will lose potential insomnia patients to primary care physicians.

Epstein says there is too much work and expertise involved with actigraphy. He likens the amount of time and expertise to a type III sleep study, yet also points out that there may be even more work involved because an actigraphy device measures patient activity over 1 to 2 weeks of time.

“You’re not looking at a single night’s worth, but 1 to 2 weeks of 24-hour data,” says Epstein. “Then you need to integrate into that sleep diary information, which shows what the patient is doing at the time that you’re getting this information. So actually, it involves a lot of evaluation on the part of both the technologist and the physician doing the interpretation.”

Reed agrees. He says, “The folks who would benefit from actigraphy, you’re going to see them serially. You need to interview [them] and understand their situation and determine if actigraphy or any other behavioral type of sleep medicine approach is applicable. A primary care physician isn’t going to be taking that approach most of the time. In many cases, they’re going to be thinking about prescribing a medication to a person and hopefully that makes this person’s problem go away, or if it’s really a chronic situation, getting them to a sleep professional.”

Epstein also believes that it takes more than standard medical school training to effectively interpret the data for sleep disorders. He says, “You need to understand sleep patterns, sleep disorders, and things like circadian physiology. So, you could be taught to turn on the actigraphy device and print out the report in a short period of time, but you really require some background in sleep in order to fully interpret what you get.”

LATEST FEATURES

Along with the study of actigraphy, the devices themselves have matured to a high level of technical sophistication.

The technology and features that exist now are just the start, however. As physicians and researchers discover new ways to use actigraphy for evaluating various therapies or conditions—inside and outside of sleep medicine—the devices will become more specialized toward a particular medical field.

Today, there are many devices on the market that have both basic and highly sophisticated features for various circadian rhythm disorders and insomnia.

When utilizing an actigraphy device for sleep medicine, Epstein recommends that the device have, at minimum, an activity monitor/accelerometer, an event marker, and an efficient computer interface for downloading data with easy-to-use software for interpretation and preparation for reports.

However, even within that basic list, small things mean a lot. For example:

  • Recording time. Patients can typically wear an actigraphy device for 1 to 2 weeks in order to get a comprehensive view of sleep/wake patterns during weekdays as well as weekends. Obviously, an actigraphy device that can record 14 days or longer would be beneficial.
  • The type of event marker. A marker button that gives some feedback to the patient, such as a beep, display icon, or even a tactile “click,” will reduce patient confusion about whether an event was marked. Likewise, a marker that is more sophisticated and asks patients to input more about the event may reduce compliance. Consequently, simpler may be better.
  • Smaller size. Advanced technology is allowing devices to get small, which is good for compliance as well as for accommodating a wider array of patients.

Additionally, in other new trends, there are actigraphy devices that deliver more information about events and the time of activity.

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One of the most significant for insomniac and circadian disorder patients is the integration of light-sensing technology.

Reed says, “If I’m a sleep physician and I want to understand why this adolescent has delayed sleep phase syndrome, then I can see from a light sensor that there’s a significant amount of light. That’s especially useful if it can tell me that it’s coming from the blue wavelength and that the time is 2 am. So, some sort of light-sensing technology is important, and ideally, if you can actually see wavelengths of the spectrum that greatly impact sleep physiology, that’s even better.”

Other feature trends that may provide useful parameters for sleep include devices that sense levels of ambient sound and/or ambient skin temperature.

FUTURE ACTIGRAPHY ADVANCES

Some future trends that will be in new actigraphy devices in the next few years include:

  • Compliance monitors, sometimes known as “off-wrist detection,” whereby physicians can tell whether the device has been taken off the patient or is defective.
  • Wireless communication between the device and the actigraphy provider will also be more prevalent.
  • Size is limited by battery power, but as battery power improves, actigraphy devices will get even smaller. In fact, ActiGraph is currently working with an apparel company that will incorporate sensors into clothing.

Finch says, “Our science is truly in its infancy, and I think within the next 3 to 5 years, you’ll see this particular science become more mainstream.”

“I don’t expect that we’re going to see actigraphy become the tool of choice for every sleep disorder,” says Reed. “That won’t be the case. But certainly, it will be applied responsibly for those disorders that the AASM has laid out in its practice parameters.”


Tor Valenza is a staff writer for Sleep Review. He can be reached at [email protected]

REFERENCE

  1. Practice Parameters for the Use of Actigraphy in the Assessment of Sleep and Sleep Disorders: An Update for 2007. SLEEP. 2007;30:519-529.