This document addresses home/portable sleep studies, multiple sleep latency testing (MSLT), and other services for the diagnosis of sleep disorders including: (1) "nap" studies; (2) actigraphy, including use of static charge sensitive beds; (3) diagnostic audio recording, with or without pulse oximetry, to document sleep apnea; (4) maintenance of wakefulness testing (MWT); (5) topographic brain mapping, and (6) acoustic pharyngometry.

Note: For information related to other technologies utilized in the diagnosis and management of sleep-related disorders, please see:

• MED.00054 Treatment for Obstructive Sleep Apnea in Adults;
• SURG.00074 Nasal Surgery for the Treatment of Obstructive Sleep Apnea (OSA) (Including Radiofrequency Ablation of Nasal Turbinates for Nasal Obstruction with or without OSA);
• Clinical UM Guideline CG-DME-32 Continuous Positive Airway Pressure (CPAP) for the Treatment of Obstructive Sleep Apnea in Adults and Children, and Related Devices for the Treatment of Obstructive Sleep Apnea in Adults;
• Clinical UM Guideline CG-MED-01 Polysomnography Studies in Adults and Children;
• Clinical UM Guideline CG-DME-27 Non-invasive Positive Pressure Respiratory Assist Devices (BiPAP^®)  .

A.    Home/Portable Sleep Studies

Medically Necessary: 

Home/portable sleep studies with Type 3 monitoring devices [minimum of 4 parameters, including ventilation or airflow (at least 2 channels of respiratory movement, or respiratory movement and airflow), heart rate or ECG, and oxygen saturation] for adults are considered medically necessary as an alternative to standard polysomnography in the following situations:

• Patients with severe clinical symptoms highly suspicious for obstructive sleep apnea, where initiation of treatment is felt to be urgent and standard polysomnography is not readily available; or
• Patient is unable to be studied with polysomnography in the sleep laboratory; or
• For follow-up after the diagnosis has already been established by standard polysomnography and therapy initiated.  For example, to evaluate the need for continuing nasal continuous positive airway pressure (CPAP) treatment in the patient who it is thought may no longer require therapy as a result of other lifestyle modifications, including significant weight reduction. or
• To confirm a diagnosis of obstructive sleep apnea in patients with a high pre-test probability of moderate to severe obstructive sleep apnea based on the presence of the following:
  • habitual snoring;  and
  • Epworth sleepiness scale score greater than 10;  and
  • obesity (BMI > 30);  and
  • witnessed apnea;  and

who are without evidence of a significant medical comorbidity (e.g., CHF, chronic pulmonary disease, or neuromuscular disease) or suspicion of other sleep disorder (e.g., narcolepsy, central sleep apnea, or periodic limb movement disorder).

Not Medically Necessary:

Home/portable sleep studies for adults are considered not medically necessary unless the criteria in the medically necessary section above relating to the use of Type 3 monitoring devices are met.

Investigational and Not Medically Necessary:

Home/portable monitoring devices for children are generally considered investigational and not medically necessary as an alternative to standard polysomnography.

B.  Multiple Sleep Latency Testing (MSLT) and Maintenance of Wakefulness Testing (MWT)

Medically Necessary:

Multiple sleep latency testing (MSLT) is considered medically necessary for the evaluation of the following conditions:

• Narcolepsy;
• Suspected idiopathic hypersomnia.

Not Medically Necessary:

MSLT is considered not medically necessary in the following situations:

• When performed for routine diagnosis of obstructive sleep apnea;
• For routine follow-up after treatment of sleep related disorders;
• For evaluation of sleepiness in medical or neurological disorders (other than narcolepsy or idiopathic hypersomnia), including, but not limited to, insomnia, circadian rhythm disorders, and Shift Work Sleep Disorder (SWSD);
• Portable MSLT performed in the home setting.

Investigational and Not Medically Necessary:

Maintenance of wakefulness testing (MWT) is considered investigational and not medically necessary for the evaluation, diagnosis or assessment of response to therapy for sleep disorders.

C.    Other Services

Investigational and Not Medically Necessary:

"Nap" studies are considered investigational and not medically necessary either for screening purposes or as an alternative to polysomnography for the diagnosis of obstructive sleep apnea or narcolepsy.

Actigraphy or static charge sensitive beds are considered investigational and not medically necessary when used as the sole method for the diagnosis or evaluation of obstructive sleep apnea.

The following diagnostic tests are considered investigational and not medically necessary:

1. Diagnostic audio recording, with or without pulse oximetry, to document sleep apnea;
2. Topographic brain mapping;
3. Acoustic pharyngometry (Eccovision^™ Acoustic Pharyngometer^®).

Based upon the available, peer-reviewed literature, in-laboratory attended polysomnography (PSG) is considered the gold standard for diagnosis of sleep-related disorders, including, but not limited to, obstructive sleep apnea, narcolepsy, nocturnal myoclonia and for titration of continuous positive airway pressure (CPAP). Multiple randomized clinical trials have established that a standard PSG should include the measurement of O₂ saturation, electrocardiography (EKG, ECG), electroencephalography (EEG), electromyography (EMG), electro-oculography (EOG), airflow, and respiratory effort measurements.  Exclusion of any of these measurements may lead to missing vital data needed to diagnose sleep disorders.

There is some controversy in the literature regarding the appropriateness of portable sleep monitors, in lieu of standard polysomnography, in the diagnosis of obstructive sleep apnea, and whether or not home-based studies are reliable.  In 2003, the American Academy of Sleep Medicine (AASM), American College of Chest Physicians, and American Thoracic Society performed an extensive evidence based evaluation; which did not support the use of a home or portable sleep study in lieu of standard polysomnography.  However, they acknowledged that it may be acceptable to perform a Type 3 study (preferably attended) in the home in the absence of the availability of standard polysomnography (Flemons, 2003).

In 2007, the AASM published a clinical guideline for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea (OSA) in adults (Collop, 2007) that specifically addressed the use of Type 3 monitors. A portable monitoring task force reviewed 37 publications from the scientific literature and made a recommendation that Type 3 monitors may be used as an alternative to polysomnography for the diagnosis of OSA in patients with a high pre-test probability of moderate to severe OSA, (since studies had largely involved patients with a high risk for moderate to severe disease) and who do not have evidence of a significant medical comorbidity (e.g., CHF, pulmonary disease or neuromuscular disease) or suspicion of other sleep disorder (e.g., narcolepsy, central sleep apnea, periodic limb movement disorder). The AASM paper continues, "Failure to meet these criteria in patients that are high risk for moderate to severe OSA should lead to an in-laboratory PSG. In laboratory PSG is also the standard in patients with other sleep disorders, such as narcolepsy and central sleep apnea." They also state, "Clinical judgment should be used in determining pre-test risk with snoring, obesity, sleepiness and witnessed apnea representing risk factors." This AASM document also states, "At a minimum, portable monitoring (PM) must record airflow, respiratory effort, and blood oxygenation. The type of biosensors used to monitor these parameters for in-laboratory PSG are recommended for use in PMs." The AASM focused its evaluation of the evidence on Type 3 portable devices, since "The previous reviews and the work of this Task Force uncovered little data on the validity and reliability of Type 2 PM devices." The AASM also noted the following:

After review of the evidence, it was the consensus of the Task Force that an experienced sleep technologist/technician or trained health care provider must be involved in the application of PM. Proper functioning of the sensors and PM equipment is essential to obtain accurate physiologic information and thus, a person thoroughly familiar with the equipment and its operation must perform the setup or provide detailed instruction to the patient.

A 2007 technology assessment performed for the Centers for Medicare and Medicaid Services (CMS) by the Agency for Healthcare Research and Quality (AHRQ) addressed home portable testing compared to polysomnography for diagnosing OSA in adults (Trikalinos, 2007). The AHRQ report concluded that, based on limited data, Type 3 monitors (among others) have a high positive likelihood ratio and low negative likelihood ratio for identifying an AHI suggestive of OSA. Also, for patients with a high probability of OSA, the use of polysomnography does not result in better outcomes over an ambulatory approach to diagnosis and CPAP titration. The increased accuracy of polysomnography does not translate into more accurate predictions of the response to CPAP based on quality of life outcome measures. However, the assessment makes several statements from which conclusions can be drawn that Type 3 monitors are less accurate than polysomnography, particularly when performed in the home setting, and states there may be substantial differences in the AHI compared to polysomnography. Unsatisfactory studies were more common in the home, and this AHRQ report noted, "…Inadequate or missing data precluding adequate interpretation was reported in 13%-20% of studies for Type 3 monitors." Thus, although the AHRQ assessment appears to support the use of Type 3 monitors overall, the observations therein suggest it is not as accurate or reliable as polysomnography, and the favorable assessment appears to be based on clinical outcomes rather than test accuracy per se.

In general, there is a preponderance of literature suggesting Type 3 monitors can be used to "rule in" OSA in patients with a high pre-test probability of moderate to severe OSA. However, high probability patients with negative or indeterminate Type 3 testing would then require diagnostic polysomnography to determine whether a sleep disorder is present and of what nature.

The available evidence in the medical literature is sufficient to recommend the use of Multiple Sleep Latency Testing (MSLT) with polysomnography for the diagnosis of narcolepsy or suspected idiopathic hypersomnia. According to the American Academy of Sleep Medicine (AASM) Practice Parameters for Clinical Use of the Multiple Sleep Latency Test (MSLT) and the Maintenance of Wakefulness Test (MWT), MSLT is indicated as part of the evaluation of patients with suspected narcolepsy to confirm the diagnosis, because the co-occurrence of obstructive sleep apnea syndrome and narcolepsy is well documented in the published literature.  This AASM paper states further that, "MSLT may be indicated as part of the evaluation of patients with suspected idiopathic hypersomnia to help differentiate idiopathic hypersomnia from narcolepsy" (Littner, 2005).

While there is sufficient evidence to recommend that polysomnography be done prior to a MSLT, there is not adequate information regarding how soon after polysomnography the MSLT may be done.  For the sake of convenience, it is common practice for the MSLT to be done immediately following the polysomnography and if not possible, the MSLT should be done within a reasonable time afterward. However, the use of MSLT as the sole diagnostic tool or performed routinely, in addition to polysomnography for the diagnosis of sleep apnea or for sleepiness associated with conditions other than narcolepsy or idiopathic hypersomnia, is not supported by evidence in the medical literature.

The utility of Maintenance of Wakefulness Testing (MWT), in terms of improved health outcomes, has not been established. The 2005 AASM Practice Parameters (Littner, 2005) note there are no standard or generally accepted guidelines for the performance of a MWT, and several variations in protocol exist, based on differences in definitions of sleep onset, trial duration and the need for previous night polysomnography. Normative data, sensitivity and specificity data in various patient groups are also lacking. Nevertheless, one suggested use has been testing an individual's ability to stay awake when public or personal safety issues are involved. However, the predictive value of MWT in this setting has not been established, and test results may not translate into behavior in workplace situations. Another potential use might be assessing the response to various treatments for disorders, such as sleep apnea or narcolepsy. However there are no established levels to indicate what represents a significant change in the test findings. Also, it is unclear that testing would provide useful information, over and above the patient's clinical response to therapy in these disorders, or would influence clinical decision-making, thereby improving patient health outcomes. The AASM concludes, "Future research is needed to define normative values using rigorous methods, to identify the impact of a standard clinical protocol for MWT, and to correlate the degree of sleepiness on objective testing with safety and occupational risks for the individual and for society in 'real life'circumstances." (Littner, 2005)

The evidence in the medical literature does not support the use of single nap studies. This type of study has not been proven to meet the standards and capabilities of sleep studies conducted in a formal sleep laboratory.  Wide deviations in the conditions and data collection methods available in these types of studies cause too much variability in the result quality for proper sleep assessment.  Additionally, nap sleep is not physiologically the same as nighttime sleep, and does not adequately reflect the range of sleep phases required for proper diagnosis, so results are not accurate when compared to full polysomnography. 

While the use of actigraphy has been demonstrated to be useful in the detection of sleep problems in "healthy" individuals, potential benefits for patients with suspected sleep disorders have not been shown.  The current body of evidence supporting the use of actigraphy for patients with sleep disorders is insufficient to allow adequate conclusions regarding efficacy.

The potential benefits of diagnostic audio recording, used alone or in conjunction with pulse oximetry, has not been demonstrated to provide clinical benefits equivalent to the currently accepted standard of care, polysomnography.  While such methods do potentially identify occurrences of sleep apnea, other aspects of physiological functioning are not recorded simultaneously, thus providing an incomplete clinical picture and allowing the possibility of misdiagnosis. Currently, there are several models of the SNAP^™ Test (SNAP Laboratories, Glenview, IL), which have obtained U.S. Food and Drug Administration (FDA) approval through the 510(k) approval process. Earlier models of this testing device are a sound collection and airflow device whereby data is recorded during sleep and returned to the SNAP laboratory for analysis.  Later models (SNAP Models 6^™ and 7^™ Testing Systems) contain additional channels of data recording, (including 3 respiratory parameters [air flow, effort, and audio] and two additional channels that monitor oxygen saturation and pulse with an optional body position channel).  As such, these newer SNAP Models (6 and 7) meet the definition of a Type III device and would be considered medically necessary when criteria are met.

The Eccovision^™ Acoustic Reflection Pharyngometer^® (Hood Laboratories, Pembroke, MA) is another noninvasive testing device intended to measure the upper respiratory airway by means of acoustic reflection.  Some studies have suggested a correlation between pharyngeal cross-sectional areas measured using acoustic pharyngometry and the presence of OSA; also that sites of airway narrowing may potentially be identified.  However, at the present time, the utility of acoustic pharyngometry measurement in the clinical setting of OSA has not been demonstrated, in terms of how this testing will impact treatment planning and clinical outcomes.

Topographic brain mapping has been briefly described in the evaluation and diagnosis of OSA.  However, the evidence is limited to small case series studies that do not allow full evaluation of this technology.  At this time, the level of evidence supporting topographic brain mapping is insufficient to make any recommendations.

Description of Sleep Disorders
Sleep disorders are some of the most common medical problems in the United States and have a significant impact on quality of life, productivity, and health.  There are many different types of sleep-related disorders, including sleep apnea, upper airway resistance syndrome, insomnia, narcolepsy, nocturnal movement disorders, such as Restless Leg Syndrome (RLS) and Periodic Limb Movement Disorder (PLMD), unexplained excessive daytime sleepiness, and arousal disorders (parasomnias). Most, if not all, of these sleep-related disorders are treatable if diagnosed properly.

Sleep disorder studies, including polysomnography (PSG) and multiple sleep latency testing (MSLT), are used to determine or confirm a diagnosis related to sleep disturbances.  These tests monitor various bodily functions including heart and respiratory rate, body position and movement, to gain an understanding of the conditions under which sleep disturbances occur.  Obstructive sleep apnea represents a very large portion and is the focus of this document.  Another type of sleep disturbance is simply known as "apnea" or "central apnea."   This condition, caused by problems in the central nervous system, is unrelated to obstructive sleep apnea and is not addressed in this document.

A Multiple Sleep Latency Test (MSLT) consists of four or five nap opportunities to determine both severity of sleepiness and presence of sleep onset rapid eye movement (REM) periods.  The presence of sleep onset REM (also known as SOREM) in a nap, as well as the number of naps in which sleep onset REM is detected, are recorded as well.  For correct interpretation, the MSLT must be performed following an all-night polysomnogram.  The patient is given the opportunity to nap at scheduled intervals for 20 minutes.  Sleep is monitored and the sleep onset (if sleep occurs) is determined by the first EEG appearance of any stage of sleep, including stage 1 sleep.  The sleep latency is the time interval from the onset of the nap to the onset of sleep on the monitored EEG. The Mean Sleep Latency is then determined by calculating the mean of the sleep latencies of the nap opportunities.

A patient receiving a MSLT should first undergo a PSG to determine if an MSLT is needed.  The MSLT may be performed immediately following or at some time shortly after a polysomnography study.  During an MSLT, the patient has various sensors attached to their body, and they are encouraged to fall asleep.  Once asleep, the patient is aroused several times and then allowed to fall back to sleep.  The time it takes for the patients to fall back to sleep is used as an indicator of various sleep disorders.  Depending upon the results of the test, a diagnosis may be determined.

Many other tests have been proposed as alternatives to PSG and MSLT tests for the diagnosis and follow-up of sleep disorders. These tests include "nap studies," actigraphy, diagnostic audio-taping, MWT, topographic brain mapping, and acoustic pharyngometry.  These tests are not currently recommended by any authoritative specialty medical organization for this purpose.

Proposed Benefits
The goal of all sleep disorder diagnostic procedures is to correctly identify a specific sleep disorder(s), in order to render proper treatment(s).  Such treatment may alleviate sleep disorder symptoms and/or causes and allow a patient to achieve healthy sleep patterns.

Potential Risks
There are few, if any, risks associated with diagnostic tests for sleep apnea, although the use of non-standard testing may lead to inaccurate diagnosis and less than optimal treatment.

Acoustic Reflection Pharyngometry^® (Eccovision^™):  is a noninvasive device that uses acoustic signal processing technology to provide a graphical representation of airway patency; the technique is based on the analysis of sound waves that are launched from a loudspeaker and travel along a wave tube into the subject's airways where they are reflected; measurement of differences in the reflected wave signals enables a graphic representation of the variations in pharyngeal cross-sectional area at several anatomic levels

Actigraphy: a method used to study sleep-wake patterns and circadian rhythms by assessing a patient's movement over a period of time; measurements usually involve the detection of wrist movements

Apnea: transient period where breathing ceases

Apnea-Hypopnea Index (AHI) or Respiratory Disturbance Index (RDI): a measure of apnea severity defined by the total number of episodes of apnea or hypopnea during a full period of sleep divided by the number of hours asleep; for the purposes of this document, the terms AHI and RDI are interchangeable, although they may  differ slightly in clinical use; an AHI/RDI greater than 30 is consistent with severe obstructive sleep apnea; in some cases, respiratory effort-related arousals (or RERAS) are included in the RDI value; these RERA episodes represent EEG arousals associated with increased respiratory efforts but do not qualify as apneic or hypopneic episodes because of the absence of their defining air flow changes and/or levels of oxygen desaturation

Continuous Positive Airway Pressure (CPAP): a noninvasive treatment for sleep apnea that involves delivery of pressurized air during sleep through a device that snugly covers the nose; the appropriate setting for standard CPAP treatment is determined during a titration sleep study

Epworth Sleepiness Scale (ESS): a standardized measure of the degree of a patient's sleepiness

Excessive Daytime Sleepiness: a condition where a person feels very drowsy during the day, even after getting adequate night time rest, and has a tendency to fall asleep or requires extra effort to avoid sleeping in inappropriate situations, such as at work or driving; also defined as a score greater than or equal to 10 on the Epworth Sleepiness Scale

Home Diagnostic Audio Recording (SNAP^™ Testing): a diagnostic test proposed for home use which may be self-administered; this test involves an audio recording of a sleeping patient, sometimes accompanied by pulse oximetry; the results may be analyzed by a computer; later models of the SNAP Testing Systems contain additional components or channels for the testing of respiratory parameters (air flow, effort, and audio) and additional channels that monitor oxygen saturation and pulse with an additional optional body position channel which would meet the definition of a Type III home portable testing device

Home/portable Sleep Study: (may also be known as NightWatch^™ System, AutoSet^® Recorder, Morpheus^™ System) a diagnostic test proposed for home use which may be self-administered or attended by a technician; the machine is returned to the doctor the following morning for data analysis

Hypopnea: breathing that is more shallow, and/or slower, than normal

Maintenance of Wakefulness Test (MWT):  a laboratory-based test intended to measure the physiological sleep tendency under standardized conditions in the absence of external alerting factors; the MWT measures the ability to stay awake for a defined period of time, (generally a 40 minute protocol is used), with the first epoch of sleep as the definition of sleep onset

Multiple Sleep Latency Test (MSLT): a test used in conjunction with polysomnography to determine the presence and severity of sleepiness; during this test the patient is given the opportunity to take naps at specified time intervals; the test consists of four or five nap opportunities at two hour intervals; each nap opportunity is 20 minutes in duration; patients with excessive daytime sleepiness may fall asleep almost immediately, while those without excessive sleepiness may not fall asleep at all; severe sleepiness is usually associated with an MSLT mean sleep latency of less than 5 minutes; the presence of sleep onset rapid eye movement (REM) and the number of naps in which sleep REM occurs is also determined

Nap Study: a shorter daytime version of a polysomnography sleep study

Narcolepsy: a neurological condition, where patients experience profound daytime sleepiness; it may also include sudden, periodic, and transient loss of muscle tone associated with extreme emotions, such as laughter or anger (cataplexy)

Obstructive Sleep Apnea (OSA):  a form of sleep disturbance, which occurs as the result of a physical occlusion of the upper airway during sleep, interfering with normal breathing; the occlusion is usually in the form of the back of the tongue and/or flabby tissue in the upper airway; this condition is associated with frequent awakening and often with daytime sleepiness

Shift Work Sleep Disorder (SWSD): a sleep disorder related to unusual or constantly changing work schedules resulting in symptoms of insomnia or excessive sleepiness

Sleep Disorder: a disruptive pattern of sleep that may include difficulty falling or staying asleep, falling asleep at inappropriate times, excessive total sleep time, or abnormal behaviors associated with sleep

SNAP^™ Testing: see "home diagnostic audio recording" (above)

Split-night Study: a combination sleep study where the first half of the night is a polysomnography study; if the study indicates obstructive sleep apnea, the second half of the study is used for a CPAP evaluation and titration

Upper Airway: the area of the upper respiratory system including the nose, mouth and throat

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

A.     Home or Portable Sleep Studies 

When Services may be Medically Necessary when criteria are met: 

When services are Not Medically Necessary:
For the procedure codes listed above for adults when criteria are not met; and for the following:

When Services may be Investigational and Not Medically Necessary:
For procedure codes listed above, when patient identified as a child, or when the code describes a procedure indicated in the Position statement section as investigational and not medically necessary.

B.     Multiple Sleep Latency (MSLT) and Maintenance of Wakefulness (MWT) Testing 

When services are Medically Necessary (for MSLT):

When services are Not Medically Necessary (for MSLT):
For the above procedure code specified as MSLT, for all other diagnoses not listed; or when the code describes a procedure indicated in the Position statement section as not medically necessary. 

When services are Investigational and Not Medically Necessary (for MWT): 

C.    Other services 

When services are also Investigational and Not Medically Necessary: 

Peer Reviewed Publications: 

1. Aldrich MS, Chervin RD, Malow BA. Value of the multiple sleep latency test (MSLT) for the diagnosis of narcolepsy. Sleep. 1997; 20(8):620-629.
2. Banks, S. et al.  Factors associated with maintenance of wakefulness test mean sleep latency in patients with mild or moderate obstructive sleep apnea and normal subjects.  J Sleep Res, 2004;13(1):71-78.
3. Banks, S, et al.  The Maintenance of Wakefulness Test and driving simulator performance.  Sleep, 2005;28(11):1381-1385.
4. Bar A, Pillar G, Dvir I, et al. Evaluation of a portable device based on peripheral arterial tone for unattended home sleep studies. Chest. 2003; 123(3):695-703.
5. Bonnet MH. The MSLT/MWT should not be used for the assessment of workplace safety. J Clin Sleep Med. 2006; 2:128-131. 
6. Carroll JL.  Obstructive sleep disordered breathing in children: new controversies, new directions. Clinics in Chest Medicine. 2003; 24(2):261-282.
7. Chesson AL Jr, Ferber RA, Fry JM, et al. The indications for polysomnography and related procedures. Sleep. 1997; 20(6):423-487.
8. D'Andrea LA.   Diagnostic studies in the assessment of pediatric sleep-disordered breathing: techniques and indications. Pediatr Clin North Am. 2004; 51(1):169-186.
9. Fletcher EC, Stich J, Yang KL. Unattended home diagnosis and treatment of obstructive sleep apnea without polysomnography. Arch Fam Med. 2000; 9(2): 168-174.
10. Flemons WW. Clinical practice. Obstructive sleep apnea. N Engl J Med. 2002; 347(7):498-504.
11. Fry JM, DiPhilippo MA, Curran K, et al.  Full polysomnography in the home.  Sleep. 1998; 21(6):635-642.
12. Gagnadoux F, Pelletier-Fleury N, Philippe C, et al. Home unattended vs hospital telemonitored polysomnography in suspected obstructive sleep apnea syndrome: a randomized crossover trial. Chest. 2002; 121(3):753-758.
13. Gozal, D, et al. "Objective Sleepiness Measures in Pediatric Obstructive Sleep Apnea." Pediatrics. Volume 108(3): 613-617. 2001.
14. Guilleminault C, Abad VC. Obstructive sleep apnea syndromes. Med Clin North Am. 2004 8(3):611-630.
15. Hatzakis GE, Karsan N, Cook J, et al.  Acoustic reflectance of pharyngeal structures in children.  Int J Pediatr Otorhinolaryngol. 2003; 67(4):373-381.
16. Kamal I.  Acoustic pharyngometry patterns of snoring and obstructive sleep apnea patients.  Otolaryngol Head Neck Surg. 2004; 130(1):58-66.
17. Kushida CA.  A predictive morphometric model for the obstructive sleep apnea syndrome.  Annals of Internal Medicine.1997; 127(8) Pt1: 581-587. 
18. Liesching T, Carlisle C, Marte A, Millman R.  Evaluation of the accuracy of SNAP technology sleep sonography I detecting obstructive sleep apnea in adults compared to standard polysomnography.  Chest. 2004; 125(3):7-11.
19. Littner M, Hirshkowitz M, Kramer M, et al. American Academy of Sleep Medicine; Standards of Practice Committee.   Practice parameters for using polysomnography to evaluate insomnia: an update. Sleep. 2003; 26(6):754-760.
20. Marcus CL. Obstructive sleep apnea syndrome: differences between children and adults. Sleep. 2000; 23(4 Suppl): S140-S141.
21. Marcus CI, et al., Respiratory sleep studies in children. Establishment of normative data and polysomnographic predictors of morbidity. American Journal of Respiratory and Critical Care Medicine. 1999; 160:1381-1387.
22. Michaelson PG, Allan P, Chaney J, Mair EA.  Validations of a portable home sleep study with twelve-lead polysomnography:  Comparisons and insights into a variable gold standard.  Ann Otol Rhinol Laryngol. 2006; 115(11):802-809.
23. Millman RP.  Full polysomnography in the home:  Has it come of age?  Chest. 1999; 115(1):6-7.
24. Monahan KJ, Larkin EK, Rosen CL, et al.  Utility of noninvasive pharyngometry in epidemiologic studies of childhood sleep-disordered breathing.  Am J Respir Crit Care Med. 2002; 165:1499-1503.
25. Mulgrew AT, Fox N, Ayas NT et al. Diagnosis and initial management of obstructive sleep apnea without polysomnography: a randomized validation study. Ann Intern Med. 2007; 146(3):157-166.
26. Netzer N, et al. Using the Berlin Questionnaire to Identify Patients at Risk for the Sleep Apnea Syndrome.  Annals of Internal Medicine. 199; 131(7):485-491.
27. Olejniczak, PW, and Fisch, BJ. "Sleep Disorders." Medical Clinics of North America. 2003; 87(4):803-833.
28. Rodway GW, Sanders MH. The efficacy of split-night sleep studies. Sleep Medicine Reviews, 2003; 7(5):391-401. 
29. Rosen CL. Obstructive sleep apnea syndrome in children: controversies in diagnosis and treatment. Pediatr Clin North Am. 2004; 51(1):153-167.
30. Series F. Accuracy of an unattended home CPAP titration in the treatment of obstructive sleep apnea. Am J Respir Crit Care Med. 2000; 162(1):94-97.
31. Silber MH. "Sleep Disorders." Neurologic Clinics. 2001, 19(1): 173-186.
32. Sterni LM, Tunkel DE. Obstructive sleep apnea in children: an update. Pediatr Clin North Am. 2003; 50(2):427-443.
33. Strollo, PJ. "Indications for Treatment of Obstructive Sleep Apnea in Adults." Clinics in Chest Medicine. 2003, 24(2): 307-313.
34. Su. S. et al  A comparison of polysomnography and a portable home sleep study in the diagnosis of obstructive sleep apnea syndrome.  Otolaryngol Head Neck Surg. 2004; 131(6); 844-850.
35. Watanabe T, Mikami A, Kumano-Go T, et al.  The relationship between esophageal pressure and apnea hypopnea index in obstructive sleep apnea-hypopnea syndrome.  Sleep. 2000; 3(4):169-172.
36. Wichniak A, Geisler P, Tracik F, et al. The influence of polysomnography on the Multiple Sleep Latency Test and other measures of daytime sleepiness. Physiol Behav. 2002; 1-15;75(1-2):183-188.
37. Yamashiro Y, et al.    CPAP titration for sleep apnea using a split night protocol.  Chest. 1995, 107(1): 62-66.
38. Young T, Skatrud J, Peppard PE. Risk factors for obstructive sleep apnea in adults. JAMA. 2004; 291(16):2013-2016

Government Agency, Medical Society, and Other Authoritative Publications: 

1. Agency for Healthcare Policy and Research. Systematic review of the literature regarding the diagnosis of sleep apnea. Evidence Report/Technology Assessment No. 1. AHCPR Publication No. 99-E002. Bethesda, MD: AHCPR, December 1998.
2. American Academy of Sleep Medicine.  Practice parameters for role of actigraphy in the study of sleep and circadian rhythms: An update for 2002.  Sleep. 2003; 26(3):337-347.
3. American Academy of Sleep Medicine.  Practice parameters for the use of portable monitoring devices in the investigation of suspected obstructive sleep apnea in adults.  Sleep. 2003; 26(7):907-913.
4. American Sleep Disorders Association Standards of Practice Committee. Polysomnography Task Force Report Sleep. 1997; 20(6):406-422.
5. American Sleep Disorders Association. "A Position Paper: Guidelines for the Clinical Use of the Multiple Sleep Latency Test." Sleep. 1992; 15(3):268-276. 
6. American Sleep Disorders Association, Standards of Practice Committee. Practice parameter for the use of portable recording of the assessment of obstructive sleep apnea. Sleep. 1994; 17(4):372-377.
7. Blue Cross and Blue Shield Assoc. Technology Evaluation Center (TEC) assessments. Portable sleep studies for the diagnosis of obstructive sleep apnea syndrome. 1996; 11(2).
8. Centers for Medicare and Medicaid Services. National Coverage Determination for Continuous Positive Airway Pressure (CPAP) Therapy for Obstructive Sleep Apnea (OSA). NCD #240.4. Effective March 13, 2008. Available at: http://www.cms.hhs.gov/apps/media/press/release.asp?Counter=2975.  Accessed on October 14, 2008.
9. Chesson AL, et al. Practice Parameters for the Indications for Polysomnography and Related Procedures. An American Sleep Disorders Association Report.  Standards of Practice Committee of the American Sleep Disorders Association.  Sleep 1997; 20: 406-422.
10. Chesson AL, et al.    Practice Parameters for the Use of Portable Monitoring Devices in the Investigation of Suspected Obstructive Sleep Apnea in Adults.  A joint project sponsored by the American Academy of Sleep Medicine, the American Thoracic Society, and the American College of Chest Physicians.  Sleep. 2003, 26(7):907-913.
11. Collop NA, Anderson WM, Boehlecke B et al. Portable Monitoring Task Force of the American Academy of Sleep Medicine. Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients. J Clin Sleep Med. 2007; 3(7):737-47. Available at: http://www.aasmnet.org/jcsm/AcceptedPapers/PMProof.pdf. Accessed on October 14, 2008.
12. Flemons WW, Littner MR, Rowley JA, et al.  Home diagnosis of sleep apnea: a systematic review of the literature. An evidence review cosponsored by the American Academy of Sleep Medicine, the American College of Chest Physicians, and the American Thoracic Society. Chest. 2003; 124(4):1543-1579.
13. Hayes Inc. Medical Technology Directory. Home sleep studies for diagnosis of obstructive sleep apnea in adults. Lansdale, PA:Hayes, Inc; April 2003. Search updated March 22, 2007.
14. Institute for Clinical Systems Improvement (ICSI).  Diagnosis and treatment of obstructive sleep apnea.  Bloomington, MN:  Institute for Clinical Systems Improvement; 2006.  Available at:  http://www.icsi.org/.  Accessed on October 14, 2008.
15. Littner MR, Kushida C, Wise M, et al. American Academy of Sleep Medicine Report: Practice Parameters for Clinical Use of the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test.  Standards of Practice Committee of the American Academy of Sleep Medicine.  2005 update intended to replace the 1992 Position Paper of the American Sleep Disorders Association on the Clinical Use of the Multiple Sleep Latency Test.  Sleep. 2005; 28(1):113-121.
16. Marcus CL, et al. American Academy of Pediatrics. Clinical Practice Guideline: Diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics. 2004, 109(4).
17. Schechter MS, et al. American Academy of Pediatrics technical report: Diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics. 2002; 109(4).
18. Thurnheer R, Bloch KE, Laube I et al; Swiss Respiratory Polygraphy Registry. Respiratory polygraphy in sleep apnea diagnosis. Report of the Swiss respiratory polygraphy registry and systematic review of the literature. Swiss Med Wkly. 2007; 137(5-6):97-102.
19. Trikalinos TA, Ip S, Raman G, et al. Home diagnosis of obstructive sleep apnea-hypopnea syndrome. AHRQ Technology Assessment Program. Agency for Healthcare Research and Quality (AHRQ), Rockville, MD; August 2007. Available at:  . http://www.cms.hhs.gov/determinationprocess/downloads/id48TA.pdf.  Accessed on October 14, 2008.
20. U.S. Food and Drug Administration 510(k) Premarket Notification Database.  Eccovision Acoustic Diagnostic Imaging Acoustic Pharyngometer Summary of Safety and Effectiveness.  No. K011329.  Rockville, MD: FDA. July 26, 2002.  Available at:  http://www.fda.gov/cdrh.  Accessed on October 14, 2008.
21. U.S. Food and Drug Administration 510(k) Premarket Notification Database.  Summary of Safety and Effectiveness. SNAP Model 6^™ Testing System.  No. K002095. Rockville, MD: FDA. March 2, 2001. Available at:  http://www.fda.gov/cdrh/pdf/k002095.pdf.  Accessed on October 14, 2008.
22. U.S. Food and Drug Administration 510(k) Premarket Notification Database.  SNAP Model 7^™ Testing System.  No. K080321. Rockville, MD: FDA. May 23, 2008. Available at: http://www.fda.gov/cdrh/pdf8/K080321.pdf.  Accessed on October 14, 2008.

1. Hood Laboratories, Pembroke, MA.  Product information: Eccovision^™ Acoustic Reflection Pharyngometry^®.  Available at:   http://www.hoodlabs.com  Accessed on October 14, 2008.
2. Journal of the American Medical Association.  Patient Page. Breathing Problems during Sleep.  Available at: http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZWT155MNC&sub_cat=593 Accessed on October 14, 2008.
3. National Center on Sleep Disorders Research. Available at: http://www.nhlbi.nih.gov/about/ncsdr/index.htm Accessed on October 14,  2008.
4. National Library of Medicine.  Medline Plus Health Information. Sleep Apnea. Available at: http://www.nlm.nih.gov/medlineplus/sleepapnea.html   Accessed on October 14, 2008.

Apnea/Hypopnea Index (AHI)
Electrosleep Therapy
Obstructive Sleep Apnea (OSA)
SNAP^™ Testing
Topographic EEG Mapping

The use of specific product names is illustrative only.  It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.