Sleep assessment made simple

The arrival of compact wrist-actigraphic technology offers a user-friendly and affordable way for you to evaluate sleep disruption and its effects.

By John A. Caldwell, PhD

Most patients seek chiropractors because of some form of pain or discomfort that is markedly affecting their daily activities at work or play. Complaints of low back pain, neck pain, whiplash, or headaches are among the most common, but other neuromusculoskeletal (NMS) issues are frequently encountered as well.1
Chiropractors, in turn, are well versed in the treatment of such conditions via manipulation, massage, exercise, and nutrition. And a variety of studies have supported the use of chiropractic and manipulation for the resolution of NMS complaints.

However, a lack of scientifically validated metrics hinders a broader acceptance of the success of various pain-reducing therapeutic strategies.

One solution to this problem is to focus less attention on measuring the pain symptomatology itself and more attention on the degree to which the pain is affecting the patients’ general quality of life. Specifically, since restorative sleep is often one of the first casualties of NMS pain, an emphasis on the resolution of pain-related sleep complaints is warranted.

Studies show that 50 percent to nearly 90 percent of patients with chronic pain complain of significant sleep disturbance.2 Furthermore, it has been established that the greater the amount of sleep disruption, the lower the pain threshold becomes.3 This means that even the most efficacious treatments for NMS discomfort may be compromised by sleep difficulties.

The case for validated sleep analysis

In light of these facts, the addition of validated sleep analysis to the clinical assessment regime can serve at least two important functions: The first is a quantification of the degree of overall patient discomfort (i.e., greater sleep disturbances indicative of greater NMS pain); and the second is a post-treatment indication of the degree to which NMS therapeutic interventions are successful (which is valuable to both the patient and the practitioner).

Up to now, however, conducting this kind of sleep assessment has been problematic. At one extreme, in-house polysomnographic studies that require an overnight stay in a specialized facility while electroencephalographic, electromyographic, and electrooculographic data are recorded are too expensive and too inconvenient. And at the other extreme, simple questionnaire-based, self-reported sleep assessments are inaccurate and unreliable.

Recent advances in wrist-actigraphic and computerized modeling technologies, however, have led to the development of sleep evaluation techniques that are well within your reach and that of your clientele. In addition, these advances offer a user-friendly and affordable way to not only evaluate sleep, but to assess the impact of sleep curtailment and sleep disruption on daily cognitive functioning as well.

The new wrist-actigraphic technologies offer easy-to-use tools that convert simple wrist movements, sampled 16 times per second, into accurate and actionable information about sleep quantity, sleep quality, and sleep/wake timing. A typical device will be waterproof, shock-resistant, durable, and can be worn comfortably in the form of a wristwatch for extended periods (Figure 1); a typical data-collection period lasts a week.

The actigraphic analysis can generate a three-part report that shows the patient’s day-to-day sleep history, average overall sleep quality, and the cognitive/performance impact of his or her sleeping habits. The report makes it relatively easy to identify the extent to which NMS pain and discomfort is creating sleep problems and, following treatment interventions, the report can demonstrate treatment efficacy.

This cutting-edge approach offers a way for patients to discover the presence of correctable sleep issues that may be unwittingly degrading their overall quality of life. Some people find they need to lengthen their average sleep duration, others have to work on eliminating sleep-disrupting environmental factors, and still others learn the importance of establishing more consistent bedtimes and wakeup times. All of these factors impact day-to-day well-being, but until a personalized report shows the extent of the impact, there often is little or no motivation for change.

Furthermore, without some type of direct feedback, the success of chiropractic treatments or basic sleep optimization strategies is difficult to judge. The actigraphy system helps solve these problems by placing the power of an individualized sleep and fatigue assessment in your hands.

Actigraphy-based sleep data collection

Although the assessment of sleep with a simple wristwatch-like device may sound too good to be true, there is a great deal of evidence supporting the validity of actigraphy-based sleep analysis. Actigraphy has been endorsed by the American Academy of Sleep Medicine and others as “an acceptably accurate estimate of sleep patterns in normal, healthy adult populations and in patients suspected of certain sleep disorders,” 4 and studies have shown that actigraphic assessments are superior to subjective sleep evaluations.5

Comparisons between polysomnographically based hypnograms and one of the newly available actigraphy-based automated in-bed and sleep/wake determinations revealed that the actigraphic device’s data agreed with polysomnography to nearly a 95-percent level.6

An actigraphy-based system provides an accurate sleep assessment without the hassle and expense of polysomnography.

While it is not possible for this type of device to diagnose sleep disorders, it makes it easy to objectively quantify sleep complaints and the degree to which effective treatments resolve those complaints.

Sleep report and cognitive effectiveness analysis

In addition, an actigraphy system that automatically processes the objectively assessed sleep history through a validated computer model, such as the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE) model, highlights the impact of sleep difficulties on cognitive performance and effectiveness.

Actigraphy-based cognitive effectiveness reports include a tabular display that illustrates the percentage of waking time being spent at each of various cognitive-effectiveness levels ranging from 100 (highly effective) to below 50 (significantly impaired). See Figure 2.  An independent 2004 evaluation of several models ranked SAFTE the highest in terms of accurately predicting the average cognitive decrements and subjective fatigue associated with sleep restriction.7

The bottom line

Providing clients with a single report that combines an objective sleep analysis with a cognitive-effectiveness summary can be an attractive and affordable strategy for including sleep evaluations in routine clinical assessments. And there is significant evidence that such assessments are of interest to today’s consumers.
In fact, an actigraphy-based device recently made available for a consumer trial conducted in Canada showed that two-thirds of the sample participants were drawn into a specific retail outlet expressly for the opportunity to have access to an easy-to-use, convenient, and accurate sleep assessment without the obtrusiveness of polysomnography (which typically records at least 12 channels of data requiring a minimum of 22 wire attachments to the patient).

If you are interested in including sleep assessments in your practice, examine the recent scientific literature concerning the importance of sleep for quality of life, safety, and performance as well as the proven connections between sleep and NMS status.

Next, consider the feasibility of including the newest sleep technology in your day-to-day practice. From both a business standpoint and a treatment-efficacy standpoint, the benefits of sleep assessment are considerable.

An industry-oriented trial completed in Australia revealed that nearly 95 percent of those who participated in a fatigue-management program were either “satisfied” or “very satisfied” with the actigraphy- based technology. Recent data also indicate that there is growing interest from within the professional sports and corporate wellness communities.

The importance of sleep is becoming more widely recognized and the inclusion of sleep evaluations in health-related activities is growing.

John A. Caldwell, PhD, is the senior scientist at Fatigue Science in Honolulu. He has served as a research psychologist with the U.S. Army for 16 years and with the U.S. Air Force for five years, focusing on sleep studies. He is a fellow in the Aerospace Medical Association. He can be contacted at john.caldwell@fatiguescience.com or through www.fatiguescience.com.

References

1Dagenais D, Haldeman S. Chiropractic. Primary Care. 2002;29(2):419-437.
2Smith MT, Haythornthwaite JA. How do sleep disturbance and chronic pain inter-relate? Insights from the longitudinal and cognitive- behavioral clinical trials literature. Sleep Medicine Reviews. 2004;8:119-132.
3Copperman NR, Mullin FJ, Kleitman N. Further observations on the effects of prolonged sleeplessness. American Journal of Physiology. 1934;107:589-594.
4Morgenthaler T, Alessi C, Friedman L et al. Practice Parameters for the Use of Actigraphy in the Assessment of Sleep and Sleep Disorders: An Update for 2007. Sleep. 2007;30:519-29.
5Westermeyer J, Sutherland RJ, Freerks M et al. Reliability of sleep log data versus actigraphy in veterans with sleep disturbance and PTSD. Journal of Anxiety Disorders. 2007;21(7):966-75.
6Russell CA, Caldwell J, Arand D et al. (2011) Controlling fatigue risk with the Fatigue Science ReadiBand™ actigraph and associated sleep/wake classification algorithms: Use case and validation. Archinoetics, LLC White Paper. Honolulu, HI: Archinotics.
7Van Dongen HP. Comparison of mathematical model predictions to experimental data of fatigue and performance. Aviation, Space, and Environ-mental Medicine. 2004;75(3, Suppl.):A15-A36.