1. When choosing among different actigraph devices on the market, what are the most important features to look for?

    • For sleep labs, the single most important feature in choosing an actigraph is its sensitivity to wakefulness, not to sleep. Some investigations on actigraphy report an impressive ability for the device to predict sleep in a subject in the title or the abstract and relegate results on predicting wakefulness to some place deeper in the body of the paper. Being a good predictor of sleep implies that a device is sensitive to immobility. However, it is the device’s sensitivity to movement that allows it to discern wakefulness from sleep accurately. Devices that are insensitive will tend to overestimate sleep. For these devices, the more instances there are of wakefulness, the worse the results can be. So it is important to look at validations that included a patient population, not just normal subjects.

  2. I have read about actigraphy being used in the diagnosis of attention deficit/hyperactivity disorder (ADHD), even though it is not yet covered by insurance. What data collected by an actigraph device indicates possible ADHD, and how reliable are these results?

    • This is no doubt in reference to the research of Martin H. Teicher, MD, PhD, at Harvard’s McLean Hospital, who has been using actigraphs to aid in the assessment and differential diagnosis of patients with ADHD for more than 15 years. Actigraphy is not used as a “doc-in-the-box” to make the diagnosis without additional input, but rather to aid in the assessment by bringing to bear additional objective data that is well calibrated, reliable, and reproducible. There are three things that can be learned with actigraphy about a subject that are pertinent to the differential diagnosis of ADHD. First, of course, is the assessment of hyperactivity. It is crucial in this instance that the subject’s activity be recorded during days when he/she is in school or at work. Although a number of studies have shown that children with ADHD are more active than controls, in terms of their mean daily activity level (frequency of movement recording mode), the differences are relatively small, with ADHD subjects being about 25% more active than healthy normals. More pertinent to the assessment is the percent of time that the individual spends during the day at very low levels of activity, because the real problem with hyperactivity in ADHD is not extreme activity but a diminished capacity to inhibit activity to low levels. This emerges as a tendency to squirm and fidget while seated. There is a much more marked and reproducible difference between ADHD subjects and controls on this measure, and many subjects who are thought to be primarily inattentive show a diminished degree of low-level daytime activity.

      The second type of information derived from actigraphy is estimates of sleep duration, sleep continuity, and sleep onset latency. Dr Teicher and others have found that children with ADHD are more active than controls, but in the absence of severe comorbidities, their sleep duration and sleep efficiency are basically normal. A serious impairment in sleep duration coupled with high activity would raise suspicion about mania. Dr Teicher also has found that children with post-traumatic stress disorder (PTSD) have a mild degree of hyperactivity coupled with a significant delay in sleep onset latency.

      Finally, actigraphy provides vital information regarding the quality and timing of the subject’s circadian rest-activity rhythm. Dr Teicher has found that children and adults with ADHD have well-preserved circadian rhythms. In contrast, subjects with major mood disorders (both unipolar and bipolar) have a dysregulated circadian rhythm. The presence of disruption in the circadian pattern would raise concerns again about an underlying mood disorder, which may be a more appropriate target for initial intervention.

      For basic review see: Teicher MH. Actigraphy and motion analysis: new tools for psychiatry. Harvard Review of Psychiatry. 1995:3;18-35.

  3. I would like to incorporate greater use of actigraphy as a home screening device for sleep disorders. For which patients is this appropriate, and for which patients is it not, and why?

    • There are very few cases where actigraphy would not be appropriate for screening, assessment of treatment efficacy, or long-term follow-up. But it should never be considered an alternative to polysomnography (PSG). There are certain populations in which PSG is impractical (demented elderly, for example). In these groups actigraphy may be the only means of making an objective assessment of sleep. Because it can be used for long-term monitoring in the patient’s own environment, actigraphy is well suited to assess suspected circadian dysfunctions. Some may also argue that actigraphy is a better measurement for periodic limb movements during sleep (PLMS) than the standard electromyogram (EMG) used in polysomnography since, by definition, the PLMS condition is one involving movement. In this case, actigraphy provides a direct measure of the phenomenon, whereas EMG is an indirect measure. Certainly the American Academy of Sleep Medicine (AASM) report “Practice Parameters for the Use of Actigraphy in the Clinical Assessment of Sleep Disorders” would be the final word on the application of actigraphy in sleep medicine.

  4. I care for a patient who has sleep apnea and possibly narcolepsy. Is actigraphy a good method to demonstrate residual sleepiness after treating the sleep apnea? If not, why not?

    —Kesavan K., Milwaukee, Wis

    • Actigraphy is not a measure of sleepiness. Actigraphy is not even a direct measure of sleep. Sleep is inferred from immobility. The probability that this inference is correct is great when one is looking at a patient's habitual sleep period. When one looks at the remainder of the day, the predictive ability of actigraphy falls off dramatically. Care should be taken when assessing daytime activity scored as sleep. I will offer two scenarios to illustrate. If there is a dramatic increase in activity during the week after treatment, one might surmise that the subject’s sleepiness has abated. But it is equally likely that the same sleepy subject happened to be on vacation at the Grand Canyon that week and simply had a more active week. Taking a good history and having the subject keep a sleep log is important. On the opposite end of the spectrum, actigraphy may show very little increase in overall daytime activity, even though your treatment has been effective. In this case, a sleepy couch potato may have been converted to a wide-awake couch potato. Properly used, actigraphy can offer insight, but there are better measures of sleepiness; certainly the multiple sleep latency test (MSLT) and the maintenance of wakefulness test (MWT) come to mind. A handheld psychomotor vigilance test (PVT) is also sensitive to sleepiness.

  5. Do you agree that wrist actigraphy (ACT) is a reliable and valid measurement to assess people with insomnia compared with the Pittsburgh Sleep Quality Index (PSQI) or a polysomnogram (PSG)? ACT has demonstrated a good reliability and validity by examining and scrutinizing epoch-by-epoch comparison with a PSG with a high correlation (r = 0.70-0.98). However, some studies reported that the PSQI has high correlations with sleep log data, but lower correlations with the PSG. Which measurements do you prefer to assess insomniacs' sleep quality and quantity? —Molly M., RRT

    • What you are describing is the classic problem that arises when one tries to compare and validate an objective measure against a subjective one. The results are never going to be as clear as one would like. Actigraphs show a high validity and reliability when compared to PSG, which is another OBJECTIVE measure. The PSQI shows a high correlation with the sleep log, which is another SUBJECTIVE measure. The problems begin when you try comparing the objective with the subjective! Being an engineer myself, I'll always favor the objective measure.

  6. Our sleep center is considering evaluating the effectiveness of medical treatment for periodic limb movement symptoms (PLMS) by using overnight actigraphy. We have several questions. Is more than one night of recording on each medication dose needed or advisable? Are there adequate billing codes to charge for the technical and professional components of the studies, and if so, what are the codes you use? Finally, what reimbursement rates are you and/or other centers receiving for these studies? We would like to offer the service and feel it would be helpful in evaluating the response of our patients to treatment, but we would like to hear from someone experienced in the field. We are concerned that the service would lose money. Thank you for you consideration.

    - David Brandes, MS, MD, medical director, Northridge Hospital Sleep Evaluation Center, Northridge, Calif

    • When it comes to actigraphy recording, more is always better. Remember, we are dealing with a single channel of information here. Taking a single snapshot in time can be chancy. If the patient has a consistent complaint of leg movements every single night, then perhaps a single night may be enough. Without this kind of information regarding the consistency of the problem, multiple nights are advisable. Certainly the recently established Category III CPT code for actigraphy demands a minimum of 3 nights of recording. However, PLM recordings are typically made with short epoch lengths (2 seconds or less) in order to be able to isolate individual leg kicks. This eats up actigraph memory quite fast. If one wanted to investigate multiple medications or doses for multiple nights and possibly allow for washout nights in between, then a device with a memory size measured in megabytes and not kilobytes is advisable.

      For more on the actigraphy CPT code, please see my response to Jim Murray, above. Reimbursement on actigraphy is not guaranteed right now. However, the capital investment is relatively small, and the longevity of these devices is typically many years. It may take a while for your lab to recover the cost of the initial investment, but it will happen. As your success in reimbursement rises, you can add more actigraphs to your fleet.

  7. In an effort to promote my sleep laboratory and integrate with the physicians in our area, I have chosen to provide actigraphy as a screening tool for the physicians' patients. I know there is no reimbursement for my lab, but is there reimbursement for the physicians? If there is, it may serve as a great marketing tool and promote a greater interest in my lab.

    —Jim Murry, director, Sleep and Neuro-diagnostics, Marshall Regional Medical Center, Marshall, TX

    • The following Category III reimbursement (CPT) code became active last July and applies to labs and physicians alike: 0089T actigraphy testing, recording, analysis, and interpretation (minimum of 3-day recording). A Category III CPT code is a preliminary code that is used to establish the usage of a particular procedure and the customary charge to the patient for the service. For this reason there is no fixed dollar amount associated with actigraphic assessment until a Category I code can be established. Medicare will not pay on a Category III code, but private insurance may. I have seen actigraph users who have made personal contact with their insurance providers receive as much as $50 per night for the application of actigraphy and $75 for interpretation. The insurance provider has to be made aware of the value of actigraphy and the possible cost benefits to the insurance company. This is not always easy. But certainly, the more this Category III code is used, the sooner a Category I code will be established with assigned dollar value for the procedure.

  8. We are slowly adding actigraphy to our sleep clinic. We know there isn't payment yet, but one of the issues we are facing is how to interpret and report the results of the information we receive from the watch. We would like it to be in the same format as our PSG reports. Any suggestions?

    —Don O., Brighton, Mass

    • Regarding interpretation, actigraphy gives estimates of sleep implied by movement, or lack of movement. As you are aware, actigraphy alone cannot reliably perform sleep staging. So actigraphic results are limited, compared to PSG, to reporting parameters that can be derived from ONLY a knowledge of sleep/wake state. These results would include things like sleep efficiency, sleep latency, and wake after sleep onset (WASO).

      Regarding report formatting, I'd recommend that you contact your actigraph provider. The company should be interested in providing a format that is easily used by the clinician. Be prepared to provide examples of formatting.

  9. Please explain actigraphy. What is the difference between a PSG and actigraphy? Will actigraphy replace the PSG? What is used to perform an actigraphy? Respiratory belts, wires, and an SAO2 monitor?

    —Emma Clark

    • Actigraphy is a method for making long-term sleep estimates in almost any environment, including the home. An actigraph is a device worn on the wrist (in most applications) like a wristwatch. The device has a motion sensor, processing circuitry, and onboard storage. Information about movement is stored in the device at regular intervals for later retrieval and analysis. Actigraphy implies whether a person is asleep or awake based on that person's level of activity. Agreement with PSG can be 90% or more in most populations. Agreement is lower in the case of the type of insomnia in which the subject lies motionless, but awake, in bed.

      Actigraphy alone cannot do sleep staging and so it will never replace PSG, but actigraphy has certain benefits over PSG. It provides information about sleep in the subject's natural environment. It can provide this information over the course of several days to several weeks. These characteristics make actigraphy a natural for investigating suspected disorders of circadian phase. Actigraphy provides a cost-effective tool for screening and follow-up that is objective and reliable.

      I would recommend consulting the recently published practice parameters paper in the journal Sleep for a complete review of the accepted uses of actigraphy.

  10. When interpreting the actigraph data, what are the criteria for sleep and wakefulness? For example, the number of movements over 5 minutes?

    —Rachael Corbett

    • The criteria for making estimations of sleep and wakefulness are embodied in algorithms provided with the software specific to each brand of actigraph. The algorithms vary. Some were determined by collecting PSG data together with actigraphy and performing regression analysis or discriminant analysis on these paired data. Typically, these algorithms assign various weighting coefficients to the activity value of the minute being evaluated and the surrounding minutes. Other algorithms follow a similar format but do NOT have their basis in a carefully calculated comparison. Instead, these algorithms typically supply a number of "sensitivity" settings such that one can adjust to change the proportion of how much sleep and wakefulness the algorithm predicts. This sort of algorithm is typically "back-validated" with a studies run that shows which types of settings might be appropriate for different populations.

  11. Where would I find the closest facility that would provide an actigraph and the follow-up process that should go along with it?

    —Moni Boobar, Lebanon, NH

    • If you are a patient or referring physician, I recommend that you contact an actigraph provider and ask what sleep labs in your area are customers. If you work in a sleep lab, then I recommend that you talk to an actigraph provider about the purchase of a system or rental with analysis service.

  12. Can you possibly recommend one or more books that may be beneficial for evaluating and interpreting actigraphy for diagnostic purposes in regard to behavioral sleep disorders.

    —Roy Hartsook

    • There are only a couple of texts that focus on actigraphy, but you won't find much on behavioral sleep disorders. While actigraphy can estimate sleep and wake with a high degree of accuracy in many populations, it is generally non-specific with regard to the nature of the sleep disturbances it can document. Papers on practice parameters discourage the use of actigraphy alone for diagnosis. However, once a sleep disorder has been diagnosed in the sleep lab and other co-morbidities excluded, an actigraph can be used to assess the degree of efficacy of a particular therapy. It's particularly useful when the actigraph has been applied in the laboratory during the PSG recording, so that the degree of accuracy in the individual case can be documented. The actigraph then allows the physician to follow the patient's treatment remotely using mail or courier service and phone consultations.

  13. Are there Actigraph normal ranges established for a healthy population for such things as sleep efficiency, sleep latency,WASO, and total sleep time? Also do different Actigraphs have comparable data?

    —Leslie Taub

    • Because actigraphy is generally very accurate in a normal population, the values for these parameters found in various papers generally come very close to what one would fine when looking at normative values for these parameters established by PSG. In sleep-disturbed populations, the accuracy of the actigraph becomes the issue and all actigraphs are not alike. Check the published validation papers using PSG as a gold standard on a mixed or sleep-disturbed population when shopping for an actigraph.

  14. What codes do you use to submit for payment on actigraphy now that they are reimbursable?

    —Michelle Kelley

    • Further information on the CPT code for Actigraphy will be published in the November Federal Register. Once the Register is published it will provide information on how to bill future actigraphy procedures. Whatever code you have been using up to this point (most likely 0089T) is what you should continue using. The new code won’t be effective until January 2009.

  15. Is there any reason to use actigraphy with children? What age limits would you impose?

    —Sandy Ricket

    • The Practice Parameters paper on actigraphy (SLEEP, Vol. 26, No. 3, 2003) indicates that actigraphy may be useful in “monitoring circadian rhythm patterns or disturbances in certain special populations (e.g., children, demented individuals)…” when PSG is either impractical or impossible. Numerous studies have been done on children of all ages and infants. In all cases but infants, where a special algorithm was devised for an actigraph placed on the upper thigh, adult wrist-worn sleep estimations have been successfully applied. Actigraphy has been used to document and provide positive feedback to parents applying behavioral interventions in children.

    • Angela:Actigraphy is a method to measure, store and analyze human motion. Actigraphy can be used to make long-term sleep estimates in almost any environment, including the home. An actigraph is a device worn on the wrist (in most applications) like a wristwatch. The device has a motion sensor, processing circuitry and on-board storage. Information about movement is stored in the device at regular intervals for later retrieval and analysis. By using actigraphy one can infer whether a person is asleep or awake based on that persons level of activity. Agreement with PSG can be as high as 90% in many populations. Agreement is lower, for example, in the case of the insomniac who lies motionless, but awake, in bed. Actigraphy alone cannot perform sleep staging and so it will never replace PSG. But actigraphy has certain benefits over PSG. It provides information about sleep in the subject's natural environment. It can provide this information from several days to several weeks. These characteristics make actigraphy a natural for investigating suspected disorders of circadian phase. Actigraphy provides a cost-effective tool for screening and follow-up that is objective and reliable. I'd recommend consulting the recently published practice parameters paper in the journal SLEEP for a complete review of the accepted uses of actigraphy.

  16. Actigraphs are currently being used to estimate activity levels as well as sleep. I have seen some cut offs for low, moderate and active persons in the literature using activity counts. I am using the Actiwatch 64 and I'm not sure how they are doing this calculation since my data looks like I have average counts/min plus or minus SD and total counts per day plus or minus SD. The literature talks about eg. moderate activity level for say 30 minutes/day. In my mind this would require minute by minute values, which I do not have. I have an interest in using my data to look at activity levels since I think that activity is related to the quality of one's sleep. Any ideas about how this is being done?

    • Leslie:First of all, you should be careful when comparing absolute activity counts when papers have used actigraphs from a different manufacturer. Some papers don’t even reference what actigraph they are using and I hope that reviewers are tougher on this issue. It is equally important to reference the mode of activity collection (some actigraphs can record movement frequency, intensity, or duration) and the epoch length. Different manufacturers provide different metrics in their software and that might be why you don’t recognize the measures cited in the literature. I’d suggest you contact your actigraph provider for more specific help on generating useful daytime information. However, if your software provides text export of raw data, you might be able to use a generic spreadsheet program or statistical package to evaluate minute-by-minute results.

    • Kim:Actigraphs record information about motor activity in a time-series (commonly once a minute). Interpretation is usually done by an automated algorithm which predicts simply a sleep or wake state based on current activity, previous activity and, to a lesser extent, future activity in that time series. It remains for the user to demark the time spent in bed in order to generate some common sleep statistics from the estimated sleep/wake pattern. With “time-in-bed” marked, well-known metrics (that don’t require knowledge of sleep staging) including sleep efficiency and WASO can be generated.

  17. The AASM pratice parameters state that a minimum of three days of actigraphy is necessary for evaluation, can a patient's activity levels be accurately established with only 3 days of monitoring, or should we continue to monitorfor up to 14 days?

    • Kristine:A weakness of actigraphy is that it is primarily a single channel of information and therefore yields results that are not very descriptive. With actigraphy, we can characterize a patient’s activity but we don’t know exactly what they’ve been up to. Balancing this is actigraphy’s main strength. It can be worn for a long period of time. Good science would dictate that one should play to the strengths of the tools being used. With actigraphy, more data is always better.

      Three days is the minimum requirement to get a decent circadian assessment (cosinor analysis, autocorrelation, etc.) with most analysis software packages, PROVIDED that the sample of data is representative of the patient's typical rest/wake pattern. Longer studies allow for small anomalies (Grandma came to visit one night during the course of a pediatric study!) to be washed out. Certainly, it pays to ask the question when retrieving a patient’s actigraph (and especially for short studies), "Was there anything noteworthy or unusual about the time period during which the recording was made that might have had an influence on activity or sleep?" Subjects usually acclimate to wearing an actigraph rather quickly. So, unless there is some reason to have the actigraph returned sooner, longer runs are always recommended.

  18. Are there any examples of classical actigraphy patterns in various types of insomnia?

    • Bashir:Examples demonstrating typical patterns of insomnia can be found in papers and abstracts published (in SLEEP mostly) by Prof. Peter Hauri who pioneered the clinical usage of actigraphy in insomniacs.

  19. Our medical director wants to implement actigraphy in our lab. Do you have a sample policy for using it, and can we bill anything for this procedure?

    • Jeanette:I recommend the most recent practice parameters paper on actigraphy (Practice Parameters for the Use of Actigraphy in the As­sessment of Sleep and Sleep Disorders: An Update for 2007. SLEEP 2007;30(4):519-529) as a source document for wording on accepted policies for actigraphy in your lab. A new billing code (95803) for actigraphy has been established in the 2009 CPT manual. However, an allowable charge for actigraphy has not yet been established for 2009.

  20. Do you have a favorite brand or model of actigraph for home use? Ours needs replacing. We would like to have 3 or 4 to use at different sites. What should I look for in the specs?

    • Kathy:When evaluating actigraphs for the purposes of estimating sleep, the most important information to ask for is the sensitivity (ability to detect sleep) and SPECIFICITY (ability to detect wake) in a mixed population (what you’d expect to see in your lab). Some companies will provide validation studies on normal subjects which are almost useless. This is because when the subject population sleeps very well even insensitive actigraphs demonstrate a high agreement to PSG. Don’t settle for published articles that demonstrate a “high correlation” with PSG. That’s also a useless statistic. Ask for published articles demonstrating the sensitivity and specificity against gold standard PSG.

  21. Is the unit similar to a telemetry recorder or is it a wireless unit that transmits the information to a monitoring station for interpretation?

    • Patrick:Commercially available actigraphs typically store data internally for several weeks. Data transmission to a host computer for analysis is then done using various techniques including, direct electrical connection, USB connection, Infrared, or short-range radio.

  22. What sort of treatment can be gained with the use of actigraphy on ADHD? How can one obtain this type of treatment for ADHD?

    • Drew:Actigraphy can be used to document activity levels and treatment efficacy. Actigraphy has been used to distinguish ADHD from Bipolar disorder (see works by Teicher). Of particular value are actigraphy modes of data collection which record movement intensity. Actigraphy has been used in research settings with some success to reduce activity levels associated with ADHD (see publications by Schulman, and also Tryon), when coupled with a reward system and immediate feedback (sound or vibration). However, no studies have been done demonstrating any effect on attention.

  23. Where can I buy an actigraph at reasonable price?

    • Jose:Actigraphs can be purchased from several sources which can be found in Sleep Review's buyer’s guide or by a simple internet search. The prices will vary depending on capabilities, such as memory and features. However, all actigraphs are not equal in their ability to distinguish sleep from wake. It is not wise to choose an actigraph based on price alone. Ask a potential actigraph provider about their device’s overall agreement (sensitivity and specificity) with PSG in a mixed or sleep-disturbed population. Do not settle for “validations” which discuss only correlations to PSG or ones that are performed on normal populations.

  24. We have a sleep lab that is interested in having an actigraphy study done on one of their patients. Can you recommend some firms that do this in the Boston area? Also, what are some of the criteria for choosing such a company?

    • Bob:Sleep Review's buyer’s guide is a great source for actigraph providers. Only a few provide an actigraphy study service which would include rental of a device and generation of sleep estimates based on actigraphy. Proximity to Boston should not be an issue since the device can usually be shipped overnight to your laboratory or directly to the patient from anywhere in the United States. The most important criteria to consider is the overall agreement of the actigraph (sensitivity and specificity) compared to PSG in sleep-disturbed or mixed populations.

  25. Are there any ICD -9 codes that we can use in order to bill for our services in reading an actigraphy?

    What are the standards for actigraphy interpretation?

    • LyNette:A new billing code (95803) for actigraphy has been established in the 2009 CPT manual. However, an allowable charge for actigraphy has not yet been established for 2009. I believe this leaves the decision about the amount of reimbursement in the hands of the insurance companies for now. Standards for the use of actigraphy have been established by the American Academy of Sleep Medicine; however, there are no standards for interpretation. Essentially “interpretation” is done when a commercially available actigraph’s algorithm performs its proprietary sleep/wake estimation. There are no standards for this, since each commercially available actigraph has different recording characteristics. Most commercially available actigraphs have published validation studies demonstrating the accuracy of their combined hardware and algorithm, which must be reported in terms of sensitivity and specificity in the population you’re are interested in or in a mixed population. Check the literature.

  26. I have a Medicare CAC meeting tomorrow and Actigraphy is on the agenda. The carrier wants to leave the status as experimental pending more research. Any comments we should bring up?

    • JY:I think enough good science has been accumulated, documenting the usefulness and defining the limitations of actigraphy in sleep medicine, including numerous practice parameters paper by the American Academy of Sleep Medicine. All the research is there. After over 20 years of peer reviewed publications, actigraphy can no longer be considered “experimental.”

  27. I believe the new code for actigraphy watch is 95803. Does this code need a modifier?

    • Sharon:We currently are unaware of any modifier being necessary for this new actigraphy code (95803). This code, as of now, still has no charge amountassociated with it. When this finally happens, more information about how to use the code may become available.

  28. Actigraphy has grown increasingly popular in health monitoring devices (ie. Body Media, fitbit, Axbo, and SleepTracker, to name a few). Many of these devices track sleep efficiency and number of "wake" events. Others do exhibit an ability to follow sleep stages, and even use this data to awaken the user during light sleep. You've mentioned, on several occasions, that actigraphs are not capable of sleep staging. Are these products vapor-ware?

    • It is not vapor-ware, but it is not sleep staging either. I would urge all readers interested in actigraphy to look for peer-reviewed validation studies for ANY claim, including one that might imply an ability to track sleep stages. It is clever marketing to offer a discussion of sleep staging and follow it with a claim of sounding a wake-up alarm during an “almost-awake moment within the sleep cycle.” No scientific evidence of what an “almost awake moment” might be is offered, and no mention of the accuracy of detection, only testimonials. There are no actual claims of sleep staging made. This is because the FDA will not allow an unsubstantiated claim (like the ability to perform sleep staging) to be advertised in the United States. What these consumer-targeted devices do is characterize periods of small movements within sleep. It was first demonstrated in 1995 (Sadeh, et al) that actigraphy could separate active sleep from quiet sleep in infants with varying degrees of accuracy. “Almost-awake moments” are similar to an infant’s active sleep that is characterized by, among other things, twitching. These devices simply sound the wakeup alarm if they manage to detect a characteristic small movement pattern within the predetermined desirable wake-up window.

  29. Could you please discuss the validity and reliability of actigraphy in patients with motor disorders such as stroke, parkinsons, etc.

    • In general, commercially available actigraphs (and accompanyingsoftware) are not validated for these populations. In cases such as stroke, the patient usually has attenuated movement. In Parkinson's Disease, the patient's gross motor activity can be confounded by the sometimes large tremor signal. You will find actigraphy-based studies in the literature on these populations looking at both sleep and daytime activity. But care mustbe taken when examining these populations clinically using actigraphy, especially using sleep algorithms that have not been validated for these populations.

  30. How do we get paid for this? None of the third party payers in this area want to pay for this.

    • Sandy:A Physician Fee Schedule was slotted to come out this month (July 2009). Whether or not a monetary value for the actigraphy code will be included therein, we do not know. What the AASM told us in late May is that it will be CMS’ (Center for Medicare and Medicaid Services) decision as to whether to leave the reimbursement of actigraphy up to the individual carriers or to publish national data in the fee schedule. We’ve been advised to watch the Federal Register this month.

  31. When billing for actigraphy, should we bill units as "1" or should we bill by day (meaning multiple units)?

    • Penny:In general, there is not much more effort involved in using an actigraph for 3 days or 14. The wording of the code, “actigraph testing, recording, analysis, interpretation, and report (minimum of 72 hours to 14 consecutive days of recording)” would suggest billing as a single unit. The minimum and maximum suggested days of recording are presented to bracket the amount of data which might be considered clinically useful.

      The minimum of 72 hours is in place because less data would significantly increase the risk that artifacts or exogenous factors effecting the recording (a car alarm going off on one particular night, for example). The maximum of 14 consecutive days is in place because no more than this amount would be necessary to document any of the disorders that actigraphy has been indicated for in the current Practice Parameters literature (with longer data sets being useful when circadian disorders are suspected).

  32. Is it appropriate to use the date the actigraph is applied as the billing date, or should it be the date it is removed, since the code includes interpretation and report?

    • Rita:Though the wording of the code doesn’t specifically state it, logic would dictate that the date of the billing would be the date the service is completed. This is because you would not bill for an incomplete test.

  33. Can both PhD psychologist sleep specialists and physicians order and interpret actigraphy? Can both bill for it to Medicare?

    • Susan: As of right now there are no special credentials required to order and interpret actigraphy. Having said that, laboratories should do their best to train staff in the operation of their actigraphs and processing/interpretation of collected data. In most cases the difficult task of scoring the file for estimated sleep periods is handled automatically by software algorithms. The task of marking/trimming unwanted data and defining the time in bed is what remains; and it isn’t always easy. Properly used event markers, written sleep logs, and other ancillary information can all help. Some devices now have off-wrist detection which will also aid in data processing. I always recommend that laboratory staff indoctrinate themselves by recording and interpreting actigraphy data collected from themselves or other willing volunteers.

  34. We are going to provide actigraph to patients and are exploring charging a deposit on the equipment. Is this commonly done and are there compliance issues we need to address?

    • Lance:You would not be the first to require a deposit on an actigraph.  But I cannot say whether it could be considered a common practice. Most patients are invested enough in their own well-being to follow through with returning with the device.  Some labs obtain a deposit for equipment or request credit card information. I have seen that some have patients sign a legal-sounding agreement acknowledging that they are responsible for the safe return of the equipment. Certainly, in some scenarios, providing a prepaid, self-addressed mailer can make actigraph returns more likely. 

      Regarding compliance, actigraphs that are sufficiently waterproof can be attached with a hospital-type band to prevent removal or data collection on someone other than the intended patient.

  35. Although I don't actually work in the field, I have a keen interest in sleep medicine, as I am an MD and have both severe OSA and severe PLMD. In regards to PLMD, excuse the obvious question but if the device is worn on the wrist then how is it able to pick up leg movements reliably? Secondly, is it financially practical for me to purchase a home unit, and if so how would I be able to interpret the data? I do have software that allows to me to interpret the smartcard data that comes off my PAP machine. Would it be something easily doable like that?

    • Scott:You are correct, we cannot assess PLM with an actigraph on the wrist. At best, wrist-worn actigraphy will demonstrate the presence of some non-descript sleep disturbance. If, after carefully completing a medical history, you have reason to suspect PLM, you would then ask the subject to wear an actigraph on the ankle (or toe depending on the manufacturer). Not all actigraphs are capable of PLM analysis, so make sure your actigraph and accompanying software support this application. Actigraph systems include some sort of means for data transfer from the device to your computer (IR, radio, or electronic transfer via your USB port). Analysis software is usually part of a purchased system, and would include an algorithm for making the sleep/wake estimates.

      The job of the analyst is to delineate the time in bed and remove any artifact (for example, off-wrist time). Actigraph systems are relatively inexpensive and there is some reimbursement available. Return on your investment can usually be expected within a year depending on how much you use the system and the reimbursement rates of the insurance carriers you deal with.

  36. What are the ranges of sensitivity and specificity that you have seen published? What would you deem as an acceptable minimum based on the products that are out there?

    • Kevin:Sensitivity is defined as an actigraph’s ability to detect sleep. Essentially, this is the actigraph’s ability to detect the absence of motion. This is fairly easy to do and so most actigraphs report a very high sensitivity (typically 90% or higher).

      Specificity is more difficult, since it requires an actigraph to detect and properly interpret small motions. Reported ranges for specificity have been as low as 24% and as high as 65%. There is a natural limit for specificity, since not every moment of awakening is necessarily accompanied by movement. It is here that a single channel of actigraphy and a multi-channel PSG diverge in their assessments of sleep/wake.

      The other natural limit in PSG/actigraphy comparisons would be the limit to which a PSG record, interpreted by independent scorers, compares with itself. While PSG is considered the “gold” standard, the results are not necessarily absolute. As one would expect, inter-rater variability also increases as sleep becomes less “normal.” The importance of an actigraph’s accuracy varies depending on the actigraph’s intended use. When looking at sleep scheduling and circadian dysfunction, accuracy compared to PSG is of less consequence than when one is trying to interpret the quality of sleep. The published sensitivity and specificity of an actigraph should always be taken into account when evaluating treatment effects.

  37. Does the reading physician generally charge for each 24-hour period that the watch is worn? If so, what is a typical fee?

    • Angela:The established reimbursement code implies a single fixed fee covering collection and analysis of anywhere from 3 to 14 days. The charge would be the same within this range. The actual length of the actigraphic study would depend on whether the device was being used for general screening (on the shorter end of the spectrum) or for assessing a possible circadian dysfunction (on the longer end of the spectrum). Since data processing and analysis are fairly automated and interpretation is not much more difficult for 14 days compared with 3, the charges are not per day.

  38. How does one go about making actigraphy part of a successful sleep clinic?

    • Alan:To make actigraphy part of successful sleep clinic, start by carefully choosing an actigraph that is well validated and reliable. Educate your staff to use the actigraph properly and collect some sample data to be sure that, when the time comes to apply the equipment to a patient, the process can be done smoothly.

      Always collect at least 72 hours of continuous data (more if the actigraph can be spared). Longer periods of collection should be considered if a circadian dysfunction is suspected. Use the actigraph according to the recommended practice parameters, taking advantage of its ability to objectively document sleep in the patient’s home environment. But keep in mind the limitations of actigraphy when using the data as part of your diagnosis and assessment of treatment efficacy.

  39. My question has to do with being reimbursed for actigraphy studies. I am a PhD psychologist, tremendous experience with things circadian, but so far the health insurance companies I've contacted tell me psychologists' contracts cannot include anything having to do with sleep or circadian rhythmicity, and that they will not add the actigraphy CPT code to my contract. Is there any way you know to help me and others in my situation?

    • Gila: The ability to attain a good night's sleep has always been a useful indicator in the assessment of mental health. Papers by Martin Teicher, Rosemary Tannock, Peretz Lavie, Avi Sadeh, Lucinda Miller, Penny Corkum and others have shown the usefulness of actigraphy in assessing ADHD, mood disorders and Post Traumatic Stress Disorder. Adding citations to your submission demonstrating the application of actigraphy could improve your chances of reimbursement.

  40. Many researchers suggested that an actigraph is not suitable equipment for insomnia study. What is your opinion? Which model do you suggest for insomnia research? Thanks.

    • Molly: In “ Practice Parameters for the Use of Actigraphy in the As­sessment of Sleep and Sleep Disorders: An Update for 2007. SLEEP 2007;30(4):519-529,” fifteen papers were cited which justify the use of actigraphy, properly applied, in the assessment of insomnia. One of the earliest papers by Hauri, et al found in 36 insomniacs “that in three-fourths of the cases, actigram and PSG agreed to within 1 hour on the total amount of sleep per night. Discrepancies, however, were not random: In patients with psychophysiologic insomnia and in insomnia associated with psychiatric disease, the actigram typically overestimated sleep when compared with the PSG. In patients with sleep-state misperception, the actigram was either quite accurate or it underestimated sleep when compared with the PSG.” Dr. Hauri went on to recommend that, in complex cases, actigraphy be ‘anchored’ with a night of simultaneous PSG in the sleep lab. When evaluating commercial actigraphs for use in any application, it is wise to ask for any validations the provider may have in the population you are studying.

  41. How do actigraphs detect AWAKE and SLEEP?

    • Actigraphs do not detect sleep or wake directly. Actigraphs infer sleep or wake based on levels of activity during the time in question and, in some algorithms, time surrounding the moment in question. The accuracy of this inference is dependent on the population, device, and circumstances. Because actigraphy usually involves a single channel of monitoring, care should always be taken when drawing conclusions especially over short periods of time.

  42. My company has been building out medical clinics & supplying equipment for 10 yrs. Is actigraphy is used in the doctor's office? Is this something we can add to our services? What are the reimbursement codes and fees? What kind of training is recommended?

    • Actigraphy is a fairly simple technique for the technically savvy. Normally there is no special training involved beyond working with the documentation supplied with the commercial purchase. Sample data is usually supplied, allowing the technical staff to get familiar with scoring and report generating. Real sleep data can easily be collected on any volunteers willing to wear an actigraph for a night or two. There are no special certifications required to use actigraphy in a clinical setting. There is funding for the procedure under Medicare and many private insurance companies are paying for this service. While sleep specialists are most often employing actigraphy, primary care physicians may also utilize this technology.

  43. What is the Medicare reimbursement for actigraphy?

    • It was recently announced in the Federal Register that a price has been provided for CPT Code #95803 – “Actigraph testing, recording, analysis, interpretation, and report (minimum of 72 hours to 14 consecutive days of recording” -- namely, $92.83 without any geographic adjustments (total RVU’s being set at three times the conversion factor of $28.3895).

  44. How can we best use actigraphy in the ICU to help evaluate sleep in patients who are interrupted during the night?

    • One of the big assumptions made when using actigraphy to estimate sleep is that any movement is due ONLY to the subject. In an ICU or other hospital environment, there is also the possibility that the patient is being moved by medical personnel. For this reason, care should be taken when evaluating actigraphy records. A good practice for ICU patients being monitored would be to log interventions which might have physically disturbed the patient. The event marker available on most actigraphs would be convenient in this practice.

  45. Is the Medicare price code for actigraphy per day or is the reimbersment the same regardless of days used? Is there any minimum requirement by CMS?

    • The reimbursement is the same regardless of the days used. A 72-hour minimum is required. Since actigraphy typically involves just the single channel of information, longer studies are always encouraged when feasible to allow the analyst to get a better impression of the patients overall ability to fall and remain asleep

  46. Per a previous question regarding the reimbursement for actigraphy using 95803, even though Medicare lists this code in the fee schedule as an allowable code, they have denied payment as not medically necessary. Per WPS Medicare customer service, the physician that does the medical review has determined that no payment will be made on the 95803. What can we do, as this is a test that can be of great importance?

    • What is lacking is a Medicare National Coverage Determination (NCD) for the actigraphy CPT code. If there is no NCD, then each Medicare Contractor makes its own local coverage determination (LCD). LCDs can’t be in conflict with a National policy--but if there is no NCD related to a service, each contractor indicates what their coverage/non-coverage is for each state the contractor oversees (i.e., an LCD for that state). So in some states, actigraphy may be paid and not in others. So the two paths to pursue would be trying to secure an LCD for your state, and then trying to secure a National Coverage Determination for Actigraphy. While actigraph providers are doing what they can to further the acceptance at the national level, actigraphy users can surely make their voices heard with their state representatives.

  47. We are having a rather difficult time getting authorization/reimbursement for actigraphy in our pediatric population. We have been told several times that actigraphy in pediatrics is still considered experimental. We have done peer-to-peer reviews on a few of our patients, but this is time consuming; and we are not always successful in reversing their decision. What would you recommend?

    • This issue is being addressed on multiple levels by actigraph providers, and sleep societies. All we can suggest to clinicians is to continue to submit, and resubmit when rejections occur.

  48. We have an Actiwatch 2 in our clinic in Cairo, Egypt (probably the only actigraphy device in Egypt). We have started using it in insomnia and circadian rhythm disorders. The results are interesting; but in a very practical/clinical sense, what is the necessity of getting an objective measure of sleep? Many of my patients simply say, "How does this help you more than my sleep diary?" Any advice?

    • Sleep Diaries have been shown to be notoriously inaccurate and this is why sleep labs are using actigraphy more and more. A patient cannot record awakenings during the night that he/she is not aware of or does not remember. Showing a patient their own actigraph record can very often be an enlightening experience. Most patients are unaware of the number of awakenings/arousals that occur during the night, or their level of physical restlessness. The objective information can quickly clear up misperceptions that a patient might have about their own sleep.

  49. We are planning to run a screening program on employees in a corporate setting to detect insomnia/poor sleep quality. In your opinion, what would be the optimum number of days to screen each employee?

    • While insurance reimbursement for clinical studies dictates a minimum of 3 nights, most researchers will record for a minimum of 7 full 24-hour periods. This will demonstrate the weekend and weeknight sleep schedules which are, very often, different. The amount of “recovery sleep” demonstrated on the weekends can give insight into the level of chronic sleep deprivation.

  50. Can the actigraphy watch detect alcohol use? How does the results detect sitting still or lying still as opposed to actual sleeping.

    • Actigraphy alone cannot detect alcohol use with any specificity. However, the actigraph can detect sleep disturbances that usually accompany alcohol use. For this reason, actigraphy has been used to screen subjects for alcohol abuse. A bad night of sleep is, though non-specific, would be followed by a blood test.

      Detection of Sleep is made by inference from lack of activity. The validated sleep estimation algorithms vary in complexity, but they all assume the intention to sleep. The algorithms are validated for people laying in bed at or near their habitual bedtime. During non-habitual bedtime periods the probability that a period defined as sleep by one of these algorithms being properly identified goes down. I discourage clinicians from automatically assuming daytime periods of inactivity identified as “sleep” by an algorithm is an actual “nap,” without confirmation from a diary. Otherwise I recommend the characterization of these intervals as “periods of quiescence which may be consistent with napping.” A similar warning applies to cases of suspected insomnia. The literature is clear that, in these patients, the probability that periods of quiescence at bedtime is reduced because this population is prone to laying in bed perfectly still while attempting to sleep.

  51. Where can I find a sample dictation of an Actigraphy report? I am looking to incorporate this tool into my practice, but would like some type of sample report to use as a template. I have already spoke with the companies that provide the Actigraphy, but they were of no help in this regard.

    • I am not aware of any source for dictation templates for actigraphy reports. In general, report wording can be leveraged from reports one might write based on PSG results, bearing in mind that Actigraphy will yield no statistics having to do with sleep architecture or staging. Remember that sleep is inferred base on motion and that results should be expressed as estimates of sleep. The exceptions to this would be statements made about sleep/rest cycles (possible circadian disorders) and PLM assessment where Actigraphy is a direct measure. Care should also be made when making statements about naps, using instead terms like “nap-like activity levels” or “intervals consistent with napping,” since sleep estimation algorithms are typically validated only for night-time sleep periods.

  52. Is there a billing code for actigraphy. If so, is there a minimum number of days; is there a difference between 7 and 14 days. Thank you

    • “CPT Code #95803: Actigraphy testing, recording analysis, interpretation and report (minimum of 72 hour to 14 consecutive days of recording).”

      There is no difference in billing or the applicable charge based on the length of the recording.

  53. How is actigraphy being utilized in the treatment of ADHD patients?

    • In a study I headed, the “BuzzBee,” a body-worn actigraph, would respond to excessive motion by generating a vibratory pulse which the child could interpret (the duration of the pulse was proportional to the degree to which the child exceeded a pre-set threshold). An operant conditioning approach was used such that the child was rewarded each day for his/her ability to remain below their target activity level. When properly motivated by a reward system children in the study were able to greatly reduce their activity levels.

  54. Does 95803 apply if the actigraph is worn only for specific periods over the course of 3+ days--for instance, if the actigraph is only worn during daylight hours?

    • Though the code description does not state this explicitly, good practice would dictate that at least 3 continuous days of activity data be recorded in order to render any meaningful interpretation. The “minimum of 72 hours” implies a CONTINUOUS recording with the exception of reasonably brief instances of removal (less than 1-hour per day, total) if the actigraph needs to be removed for bathing, etc. Collecting 72 hours of non-continuous data (days only, or nights only) prevents the clinician from understanding the complete picture of the subjects sleep/activity cycle. Indications of excessive daytime somnolence, for example, would be missed if the actigraph is worn only at night.

  55. Are the software algorithms for actigraphy easily available or is it proprietary? Thanks.

    • Any commercial actigraph provider claiming a “validated” algorithm should have a peer reviewed publication available to back up that claim which details both the algorithm mathematics and the results. Be very careful that an algorithm suggested by a manufacturer was actually validated for the device they are selling. The actigraph provider is always mentioned in the validation publication.

  56. We have had a problem with patients returning actigraphy equipment in good condition, if at all. Is it really worth the expense for the information it will add?

    • The actigraph can provide insight that cannot be gained from a single night in the sleep lab. For example, the actigraph can examine a patient’s sleep/wake schedule when a circadian disorder is suspected. The diagnosis of a circadian disorder is less about sleep architecture, and more about long-term patterns that an actigraph can provide. In instances of suspected insomnia, examination of several 24-hour cycles can reveal instances of daytime napping and can illuminate problems which are purely related to proper sleep hygiene. So, performing an actigraph study on every patient is not warranted and will result in excess wear-and-tear on your equipment. But there are circumstances where an actigraph study may be the best (and least expensive) course of investigation.

  57. Are there any published data about actigraph reliability (mechanical sense, not accuracy or correlation to sleep) that would guide purchasers?

    • There are no “technical reliability” studies published. Occasionally some authors will mention fall-out in an actigraphic study based on “technical difficulties.” This, however, is rare. These technical difficulties can encompass a wide range of problems, which can also include user error (like forgetting to change or properly charge a battery), along with true device failures. Also, some populations provide a tougher environment for data collection (e.g. pediatrics, demented elderly) and so reports of technical difficulties need to be viewed in light of the population being studied. FDA requires Class II medical device manufacturers to trend actigraph failures and provide corrective and preventative action based on trends whenever possible, so each manufacturer can continually work towards providing the most reliable product possible. My recommendation is to speak with colleagues that have used the actigraphs you are interested in purchasing, especially if they are involved in a similar population. Also check with the actigraph providers about their warranty and return policy. Some offer immediate exchanges for problematic devices under warranty and “loaner” equipment during repair periods.

  58. Which diagnostic codes are currently being reimbursed? The 2010 Medicare LCD seemed to appropriate actigraphy for SDB-related issues, but not CRSDs, insomnia, etc. Any info on reimbursement trends, which payors are paying for which dx, is much appreciated. I'm an expert in clinical and research use, but impeded in practice from incorporating re: billing hangups. Not asking to discuss "fees" (although we may go cash on actigraphy), but which disorders are being covered. Many thanks.

    • The code established for Actigraphy in Sleep Medicine, “CPT Code #95803–Actigraph testing, recording, analysis, interpretation, and report (minimum of 72 hours to 14 consecutive days of recording," is non-specific regarding diagnosis. Theoretically, reimbursement should apply to any application of actigraphy that is medically indicated. The latest practice parameter’s paper in SLEEP should be your resource in making the determination of acceptable situations where actigraphy should be used. These should include cases of suspected insomnia and circadian rhythm disorders, as you suggest. We encourage all actigraph users to continue submitting actigraphy for reimbursement even if rejection is expected. Making the powers-that-be aware of the prevalence of actigraph usage in clinical practice is one of the ways this code may one day be approved for National Coverage Determination (NCD).

  59. Our research program has been using actigraphy for quite some time now, but we are looking to expand our program and offer implementing actigraphy into several new investigator's studies. The idea is to keep it simple and make it almost as if they are selecting from a menu. Are there any papers/guidelines that give recommendations in terms of what is best for different populations and what settings changes should occur? (I have read the Practice Parameters and some associated papers.) Any help or insight would be greatly appreciated as this is all new to me.

    • Whenever possible, research the available published literature to see how others have used actigraphy in the population you are examining. Not all authors will include details of device models, modes of operation, algorithms and settings that might be available. If this information is not included in the publication, write to the lead author and ask. In most cases the authors will be happy to share details of their experience both with the equipment and the study population. I would also recommend contacting your actigraph provider, who will certainly have recommendations for you.

  60. We are still having many issues getting Actigraphy authorized for our pediatric patients. Most parents are not willing or cannot afford a self-pay plan. Our watches are sitting idle in a drawer. Any progress on educating the payors on the benefits of actigraphy in the pediatric population?

    • The effort to educate payors is ongoing. While there is what many would consider overwhelming evidence that actigraphy can be a useful and cost-saving tool in most clinical practices including pediatric sleep, there is unfortunately at least one published paper demonstrating very low specificity in a pediatric population. The author draws the generalized conclusion that “actigraphy” should not be used, though these results appear to apply only to a single brand of actigraph. A similar published paper exists for an adult population. Reports we have seen from third party payers focus on these publications and then go on to conclude that actigraphy is an “experimental” science and should not be reimbursed.

  61. Is the procedure reimbursable by Medicare and major insurances?

    • Although Category l CPT Code #95803 for actigraph testing, recording, analysis, interpretation, and report (minimum of 72 hours to 14 consecutive days) has been established and Medicare increased the technical component of an actigraph test by 56% in 2011 (yielding a global reimbursement fee in excess of $160), there is still no National Coverage Determination (NCD). If there is no NCD, then each Medicare Contractor makes its own local coverage determination (LCD). LCDs can’t be in conflict with a National policy – but if there is no NCD related to a service, each contractor indicates what their coverage/non-coverage is for each state the contractor oversees (i.e., an LCD for that state). So in some states, actigraphy may be paid and not in others. Insurance companies generally follow the lead of Medicare in their state. But there has been some success in instances when an appeal has been made with the proper medical justification. In any case I would encourage you continue to submit both to Medicare and private insurance to make them aware of the frequency of clinical use of this procedure.

  62. What would a typical report consist of or look like?

    • In many cases the contents of an actigraph clinical report are customizable. But generally, they’ll consist of demographic information about the patient, a graphical presentation of the Actigram (activity histogram) for the period of the recording and then a tabular presentation of night time and, sometimes, daytime statistics. Again, these statistics can usually be customized but generally present sleep statistics that are familiar to the sleep professional, like Total Sleep Time, Sleep Onset Latency, Sleep Efficiency WASO, etc. All reported values are based only on an estimate of sleep/wake based on the application of a (hopefully) validated algorithm and never include any information about sleep architecture.

  63. I have patients sign a form stating they are financially responsible if the Actigraph is not returned or damaged. So far we have not had a problem. However, I have yet to be reimbursed by any insurance company for Actigraphy. The usual statement is "it is not proven and considered investigational."

    • Third party payers are sometimes making a blanket decision that ACTIGRAPHY, “is not proven and considered investigational," based on a cursory review of the literature that shows that SOME types of actigraphs in SOME populations show poor specificity. My recommendation is that you find a validation article for your particular type of actigraph (in the relevant population, if it can be found) and submit this to the payer to rebut their decision. Your actigraph provider should be able to help you with this documentation.

  64. How can a researcher best ensure that a participant remembers to hit the event marker button when they get in bed and arise the next morning? Any suggestions for increasing compliance with this instruction given that so many forget to do this?

    • There is no perfect solution to this problem. This is the down-side of the ad-lib study. I have seen some studies that do a daily phone call to the subject which includes reminding them to press the event button to demark the sleep period. This seems to have a limited amount of success. Setting up rules based on activity values or using automated software processes for marking time in bed are viable alternatives and should be used with consistency. The other issue is how to handle event marks that clearly contradict what the actigraph histogram is saying. For example a “goodnight” event mark may be missing but the subject remembers in the middle of the night during a trip to the restroom and presses the button. Or, they remember to make their “good morning” mark sometime during breakfast! This is where the analysts interpretation based on context is important.

  65. Can you tell us the best way to interface an actigraphy signal into the polygraph for use of actigraphy during PSG? This would allow us to truly integrate actigraphy into all levels of polysomnography.

    • Some actigraph providers allow export of either activity values and/or sleep-wake determinations based on their sleep algorithm. So actigraphy can be imported into PSG systems that have this capability.

  66. How accurate are the estimates of sleep latency, total sleep time, wake after sleep onset, and sleep efficiency in various actigraphs?

    • Each actigraph provider should be able to provide you with published, peer-reviewed validation studies using their actigraph with their own algorithms. Beware of providers that can’t provide these or who use algorithms developed for actigraphs that are not their own. In general you will find that actigraphs can be very accurate in patients with good sleep, but less so with patients who have sleep disturbances. It is the actigraphs specificity (ability to distinguish wakefulness) in a particular population that should be examined. In some types of insomnia where patients lay awake but motionless, the accuracy of actigraphy can decrease dramatically. So care must be taken and consideration given to the other symptoms and complaints of a subject when examining actigraphic results.

  67. Would actigraphy testing dovetail with sleep hypoxemia testing? For patients being prescribed AVAPS sytems, would you see a beneficial application doing actigaphy simultaneous to these studies?

    • Actigraphy will certainly answer the question about whether there are awakenings associated with desaturations. Because actigraphy is easy to use and inexpensive, the case can certainly be made that it provides an added dimension with very little added effort/cost.

  68. Can you please give us numeric values associated with movement time on the actigraph printout? For example, if there is 6 hours of recodeing time where the patient claims to be asleep, how much movement time would be considered normal?

    • In my experience 20% to 30% is the normal range for the “percentage of time spent in motion” measured by actigraphy during the sleep period. Some systems call this value “movement time” while others call it “activity index.” Of course the actual value will also depend on the sensitivity of the actigraph you are using. Less sensitive actigraphs will naturally show less of the small movements which occur during normal sleep. Larger values are associated with “restlessness.” This percent of time spent in motion includes all motion, regardless of whether said motion contributes to an actigraphically scored awakening according to the algorithm employed, and has been used successfully as an outcome measure in studies of conditions like Atopic Dermatitis.

  69. What is the reimbursement picture for pediatrics and actigraphy? The last I heard, there was no reimbursement and my employer will not permit purchase.

    • While reimbursement is not guaranteed at this point in time, pediatrics is usually an area where an accompanying medical justification suggesting that full PSG is not warranted and not easily tolerated in a particular case can increase your chances of reimbursement because it is more fully in line with recommendations by the published practice parameters papers which indicate that actigraphy is called for in populations where PSG is impossible or not well-tolerated.

  70. As a member of the quality management department, I assist staff in developing quality indicators related to patient safety and compliance. Can you recommend some indicators that could be used for our sleep lab? I am thinking of things like a complete medical history prior to study, timeliness of results to patient and ordering physician. Are there others that we should be using?

    • When it comes to actigraphy, compliance can usually be judged from a visual inspection of the data. Because there is always some small amount of motility during sleep, large gaps of complete inactivity usually denote periods when the actigraph was removed. Some varieties of actigraphs even have special technology to help make determinations of periods when the actigraph was off-wrist. It’s up to the analyst to decide if the timing and duration of the actigraph removal were sufficient to make a determination of non-compliance.

  71. We were denied coverage for actigraphy on a medicare patient because CMS said it is experimental. I billed under CPT code G0400 and then tried 95803. Have you experienced denials of this type in the past?

    • Yes, many CMS are considering actigraphy experimental, citing peer reviewed publications where certain brands of commercially available actigraphs demonstrate very low specificity (ability to detect wakefulness during the sleep period). This is not true of all brands of actigraphs. But perhaps, in the current economic atmosphere, they are ignoring the plethora of good evidence and generalizing the results from some inaccurate actigraphs to ALL actigraphs. It is my feeling that only actigraphs devices with the proper peer-reviewed evidence of accuracy should be reimbursable.

  72. Are you aware of any actigraphy devices capable of integrating oximetry within the actual recording?

    • I’m not aware of any actigraph device capable of oximetry, because of the large size and power drain of this added technology. However, you should be able to find oximetry devices with actigraphy capabilities, since oximeters are usually large enough to house the added accelerometry necessary and there’s usually ample battery power to run the added circuitry. As always, check the provider for validation of actigraph channel.

  73. Several watch devices advertise that they are able to determine position. How does a wrist device determine if a patient is positioned supine, lateral, or prone?

    • In general a tri-axial accelerometer can make a determination of the direction in which gravity is pulling. Just as sleep estimates are inferred from motion, position can be inferred by the direction of gravity relative to the device. The accuracy of these inferences varies with the placement of the actigraph. Wrist placement is the least accurate for position (but best for estimating sleep). Ankle placement is more reliable for distinguishing standing from lying. Torso or upper arm placement has the best chance of correctly inferring supine, lateral, and prone positions but the lowest likelihood of detecting awakening associated with small movements.

  74. Is actigraphy covered by both commercial payors and Medicare? What is the reimbursement?

    • Coverage for actigraphy for Medicare varies from state-to-state and also among commercial payors. When covered, reimbursement between $80 and $120 for recording, analysis, and interpretation has been noted. Unfortunately, many payors have focused on publications showing the poor specificity (the ability to detect night-time awakenings) of some specific brands of devices, and use these publications to draw a generalized conclusion that actigraphy as a science is experimental.

  75. Is actigraphy a billable service? What are the main indicators?

    • Actigraphy is a billable service (CPT code 95803). Actigraphy is indicated in situations where full PSG is impractical (like pediatrics) or impossible (suspected circadian rhythm disorders) and can be used to rule out the need for full PSG studies in cases where poor sleep hygiene is suspected.

  76. Why should an actigraphy device be worn on the non-dominant hand? What happens if it's worn on the dominant hand?

    • While studies have shown no significant difference in mean nocturnal activity between wrists, in general, the dominant wrist is slightly more active than the non-dominant. I’m not aware of any studies that have evaluated the accuracy of any particular algorithm on the dominant versus non-dominant hand. So we have no information on how the sleep estimate may change with placement. Naturally, sensitivity to placement would also depend on the algorithm and the sensitivity of the actigraph. Since sleep estimation algorithm development and validation studies have been conducted using the non-dominant hand, I’d recommend using the non-dominant hand whenever it’s feasible. Clinically, it’s more important that the actigraph be worn on the same hand between baseline, treatment, and any possible follow-up study, so that changes in estimated sleep are not caused by changes in placement. It’s better to have dominant hand data than no data, but avoid mixing dominant and non-dominant hand data.

  77. Do you use actigraphy to support diagnosis of insomnia and/or circadian rhythm disorders? Are you having reimbursement issues, claiming actigraphy is investigational?

    • Yes, these are both very good applications for actigraphy because they take advantage of its ease of use and long-term data collection. And yes, there have been reports of some private insurance providers claiming actigraphy is investigational based on some very poor published results of some particular brands of actigraphs. Remember, 510(k) clearance to market from the Food and Drug Administration (FDA) is not an endorsement by the FDA. Not all actigraphs are alike in their ability to assess sleep (sensitivity) and awakenings (specificity). If you are being denied reimbursement, resubmit with copies of peer-reviewed validation papers. If your actigraph provider can’t provide these validations, switch actigraphs!

  78. Which actigraphy devices have been validated against polysomnography? What percentage of correlation can we expect in relation to sleep/wake/sleep disruption percentages?

    • It’s easy to find which devices have been validated against polysomnography (PSG). Simply go to the provider’s website. If they have validations against PSG, they are proudly and prominently noted there. If the company has no validations, or the validations are poor, you won’t find them and might even get an evasive answer if you email asking for them. Also, don’t ask for “correlations” to polysomnography. Ask for agreement rates, sensitivity and specificity! Agreement rates reflect how well the actigraph detects sleep where PSG detects sleep and wake where PSG detects wake. Actigraphs with poor agreement to PSG can still have fairly high correlation to PSG results. High sensitivity (sleep detection) is easy to achieve, especially if the population used in the validation is normal. Most providers can document sensitivity in the mid to high 90% range in most populations (the exception being cases of insomnia where the subject is wide awake, but motionless). High specificity (wake detection) is much more difficult to achieve, without sacrificing sensitivity. Some commercially available devices fall below 50%, especially with a sleep-disturbed population. A good actigraph should be at least better than chance at picking up awakenings!

  79. We are in the process of implementing the use of actigraphy in our sleep lab. Can you suggest any type of education for both physicians and sleep technologists?

    • Since actigraphy is a relatively simple technology compared to most other gear found in a sleep lab, you won’t find much in the way of formal education programs available. While the generalities of scoring and interpretation are universal, the nuts and bolts of daily use are specific to the type of device you have purchased. When it comes to actigraphy training, hands-on is the best form. Each person involved in actigraphy should be required to read the manuals included with the device and collect a week of data on themselves, which they can then analyze. The trainee should have access to your device provider’s customer service department for any troubles with initialization or data retrieval and the opportunity to work with experts analyzing and interpreting their own data. You can use your own in-house actigraphy veterans or your actigraph provider’s experts via phone and shared-computer sessions.

  80. Our research team (toddler sleep study) has a question regarding to actigraph data processing: In a 14-day actigraph data collection, only 3 days show good data. Is it feasible/appropriate to process this data? Why or why not?

    • That would depend, to some extent, on why you did not get “good data” on the remaining 11 days. If you can be sure that there was only a simple compliance problem (the actigraph was not worn the remaining days), then the 3 days should be usable, provided these 3 days of data seem reasonable (an expected diurnal variation and activity level is observed). If the actigraph has malfunctioned, then I would suggest exercising more caution. One way to differentiate between a malfunction and a compliance problem is to further test the actigraph in question on yourself for 24-hours and see if the data collected is reasonable.

  81. We conducted a study in which we used two different actigraphy models. I am planning to compare sleep/wake estimates from actigraphy with PSG results, and I was wondering if we could combine these two sets of data to increase statistical power. What would (if any) the acceptable disagreement between the two devices be?

    • In general, it’s never a good idea to mix actigraphs models within a study. Each actigraph (and its associated sleep estimation algorithm) has its own sensitivity and specificity when predicting sleep/wake. Because of differences in device sensitivity, one actigraph may overestimate sleep and another underestimate sleep. These differences are not linear and so there’s no way to “adjust” for actigraph model.

  82. When we use an actigraph on the ankle instead of the wrist, is there anything specific that we're supposed to ask the mother to note in the sleep log? Is there any difference in filling up the sleep log?

    • When using the actigraph on the ankle in pediatrics, the same care should be taken with a written log as one would if the actigraph were worn on the wrist. Times of actigraph removal and times when the child is traveling in a vehicle are particularly important to have the parents document.

  83. Which sleep metrics can be measured accurately with actigraphy?

    • Actigraphy can supply any sleep metric that is delivered by PSG that doesn’t involve sleep staging. Actigraphy can only estimate sleep and wake. The accuracy of any actigraphic metric is solely based on the actigraph’s ability to distinguish sleep (sensitivity) and wake (specificity). If your actigraph provider doesn’t have published validity papers showing high sensitivity and specificity, consider another actigraph! Also note that sleep latency (or Latency to Persistent Sleep) is probably the least reliable metric. This is due partly to the fact that falling asleep is a transitional state. Some patients toss and turn; others may lay perfectly still and stare at the ceiling. The other problem is that, while the start of a sleep recording is well defined in the sleep laboratory, the time the patient goes to bed with the intention of sleep can be harder to establish with an actigraph (though light sensors and event markers can certainly help with this).

  84. Can the sensor be placed anywhere else, such as the forehead, ear, mouth, or nose?

    • Over the years I’ve seen many different placements. Depending on the size of the actigraph, any placement is possible, at least for a while. Compliance becomes an issue when devices are placed on the face. If you intend to measure sleep in these locations, there may be some sensitivity loss as you move away from the wrist and applying sleep algorithms developed for the wrist would not be optimal.

  85. If you have an actigraph data collection period occurring across a daylight savings time shift, how does AW2 treat the data occurring after the shift? Follow up question: Is there a way to manually shift the data by 1 hour to account for daylight savings?

    • Actigraph data collected across a daylight savings time shift (or across time zones) do not need to be manipulated in any way. The meaningful statistics such as sleep efficiency, sleep latency, and WASO are all independent of the actual time that they are calculated. Lights-off and lights-on times will be the only metrics that will be shifted by an hour (though they are a truer representation of the patient's internal clock). The real reason that actigraph recordings across these time shifts is discouraged is because you are introducing an additional circadian disturbance to sleep quality that doesn’t need to be there (unless you’re specifically trying to measure these effects).

  86. How would you rate the info obtained from the Fitbit device? It gives apparent actigraphic data as well as movement data.

    • Medical-grade actigraphs with FDA clearance to market as medical devices are typically close to 90% in agreement with PSG for sleep/wake predictions. The PSG comparisons I’ve seen for Fitbit show that it has a 70% in agreement with PSG. This is not a surprising result since the Fitbit design was optimized for step counting and energy expenditure estimates, not for sleep estimations. FDA prohibits medical claims in advertising for devices that are not cleared. Manufacturers of consumer devices like Fitbit use the ambiguous term of “sleep tracking,” hoping the FDA sees this as a non-medical claim.