Permanent standard time is the optimal choice for health and safety: an American Academy of Sleep Medicine position statement.

The period of the year from spring to fall, when clocks in most parts of the United States are set one hour ahead of standard time, is called daylight saving time, and its beginning and ending dates and times are set by federal law. The human biological clock is regulated by the timing of light and darkness, which then dictates sleep and wake rhythms. In daily life, the timing of exposure to light is generally linked to the social clock. When the solar clock is misaligned with the social clock, desynchronization occurs between the internal circadian rhythm and the social clock. The yearly change between standard time and daylight saving time introduces this misalignment, which has been associated with risks to physical and mental health and safety, as well as risks to public health. In 2020, the American Academy of Sleep Medicine (AASM) published a position statement advocating for the elimination of seasonal time changes, suggesting that evidence best supports the adoption of year-round standard time. This updated statement cites new evidence and support for permanent standard time. It is the position of the AASM that the United States should eliminate seasonal time changes in favor of permanent standard time, which aligns best with human circadian biology. Evidence supports the distinct benefits of standard time for health and safety, while also underscoring the potential harms that result from seasonal time changes to and from daylight saving time. CITATION: Rishi MA, Cheng JY, Strang AR, et al. Permanent standard time is the optimal choice for health and safety: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2024;20(1):121-125.

"Count on Sleep": an OSA awareness project update.

Obstructive sleep apnea (OSA) is a common, chronic sleep-related breathing disorder that affects approximately 12% of the US adult population. Greater public awareness of OSA is necessary to decrease the number of people with undiagnosed or untreated OSA and reduce the negative health consequences of unrecognized OSA. In 2021, the American Academy of Sleep Medicine initiated the "Count on Sleep" project in partnership with key stakeholders with the objective of raising the awareness of OSA among the public, health care providers, and public health officials. Four workgroups implemented strategies and completed tasks focused on increasing OSA awareness in their targeted areas to address the objectives of the project including (1) Public Awareness and Communications, (2) Provider Education, (3) Tool Development and Surveillance, and (4) a Strategic Planning workgroup that coordinated efforts across the project. Over the first 2 years, workgroups made substantial progress toward project goals including holding "listening sessions" with representatives of communities disproportionately affected by OSA and its consequences, developing resources for primary care providers that can be easily accessed and used in practice, and developing a brief survey for use in estimating and tracking OSA risk across the population. Over the first 2 project years, workgroups made significant progress in advancing efforts to increase awareness of OSA in US communities. The third year of the project will focus on dissemination of campaign materials and resources for all targeted groups, including the public, health care professionals, and public health professionals. CITATION: Martin JL, Rowley J, Goel N, et al. "Count on Sleep": an OSA awareness project update. J Clin Sleep Med. 2024;20(2):303-307.

Age and weight considerations for the use of continuous positive airway pressure therapy in pediatric populations: an American Academy of Sleep Medicine position statement.

This position statement provides guidance for age and weight considerations for using continuous positive airway pressure therapy in pediatric populations. The American Academy of Sleep Medicine commissioned a task force of experts in pediatric sleep medicine to review the medical literature and develop a position statement based on a thorough review of these studies and their clinical expertise. The American Academy of Sleep Medicine Board of Directors approved the final position statement. It is the position of the American Academy of Sleep Medicine that continuous positive airway pressure can be safe and effective for the treatment of obstructive sleep apnea for pediatric patients, even in children of younger ages and lower weights, when managed by a clinician with expertise in evaluating and treating pediatric obstructive sleep apnea. The clinician must make the ultimate judgment regarding any specific care in light of the individual circumstances presented by the patient, accessible treatment options, patient/parental preference, and resources. CITATION: Amos L, Afolabi-Brown O, Gault D, et al. Age and weight considerations for the use of continuous positive airway pressure therapy in pediatric populations: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2022;18(8):2041-2043.

Enhancing public health and safety by diagnosing and treating obstructive sleep apnea in the transportation industry: an American Academy of Sleep Medicine position statement.

Obstructive sleep apnea (OSA) may lead to serious health, safety, and financial implications-including sleepiness-related crashes and incidents-in workers who perform safety-sensitive functions in the transportation industry. Evidence and expert consensus support its identification and treatment in high-risk commercial operators. An Advanced Notice of Proposed Rulemaking regarding the diagnosis and treatment of OSA in commercial truck and rail operators was issued by the Federal Motor Carrier Safety Administration and Federal Railroad Administration, but it was later withdrawn. This reversal has led to questions about whether efforts to identify and treat OSA are warranted. In the absence of clear directives, we urge key stakeholders, including clinicians and patients, to engage in a collaborative approach to address OSA by following, at a minimum, the 2016 guidelines issued by a Medical Review Board of the Federal Motor Carrier Safety Administration, alone or in combination with 2006 guidance by a joint task force. The current standard of care demands action to mitigate the serious health and safety risks of OSA. CITATION: Das AM, Chang JL, Berneking M, et al. Enhancing public health and safety by diagnosing and treating obstructive sleep apnea in the transportation industry: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2022;18(10):2467-2470.

Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine clinical practice guideline.

INTRODUCTION: This guideline establishes clinical practice recommendations for the treatment of central disorders of hypersomnolence in adults and children. METHODS: The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine to develop recommendations and assign strengths to each recommendation, based on a systematic review of the literature and an assessment of the evidence using the GRADE process. The task force provided a summary of the relevant literature and the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations that support the recommendations. The AASM Board of Directors approved the final recommendations. RECOMMENDATIONS: The following recommendations are intended to guide clinicians in choosing a specific treatment for central disorders of hypersomnolence in adults and children. Each recommendation statement is assigned a strength ("strong" or "conditional"). A "strong" recommendation (ie, "We recommend…") is one that clinicians should follow under most circumstances. A "conditional" recommendation (ie, "We suggest…") is one that requires that the clinician use clinical knowledge and experience and strongly consider the individual patient's values and preferences to determine the best course of action. Under each disorder, strong recommendations are listed in alphabetical order followed by the conditional recommendations in alphabetical order. The section on adult patients with hypersomnia because of medical conditions is categorized based on the clinical and pathological subtypes identified in ICSD-3. The interventions in all the recommendation statements were compared to no treatment. 1: We recommend that clinicians use modafinil for the treatment of narcolepsy in adults. (STRONG). 2: We recommend that clinicians use pitolisant for the treatment of narcolepsy in adults. (STRONG). 3: We recommend that clinicians use sodium oxybate for the treatment of narcolepsy in adults. (STRONG). 4: We recommend that clinicians use solriamfetol for the treatment of narcolepsy in adults. (STRONG). 5: We suggest that clinicians use armodafinil for the treatment of narcolepsy in adults. (CONDITIONAL). 6: We suggest that clinicians use dextroamphetamine for the treatment of narcolepsy in adults. (CONDITIONAL). 7: We suggest that clinicians use methylphenidate for the treatment of narcolepsy in adults. (CONDITIONAL). 8: We recommend that clinicians use modafinil for the treatment of idiopathic hypersomnia in adults. (STRONG). 9: We suggest that clinicians use clarithromycin for the treatment of idiopathic hypersomnia in adults. (CONDITIONAL). 10: We suggest that clinicians use methylphenidate for the treatment of idiopathic hypersomnia in adults. (CONDITIONAL). 11: We suggest that clinicians use pitolisant for the treatment of idiopathic hypersomnia in adults. (CONDITIONAL). 12: We suggest that clinicians use sodium oxybate for the treatment of idiopathic hypersomnia in adults. (CONDITIONAL). 13: We suggest that clinicians use lithium for the treatment of Kleine-Levin syndrome in adults. (CONDITIONAL). 14: We suggest that clinicians use armodafinil for the treatment of hypersomnia secondary to dementia with Lewy bodies in adults. (CONDITIONAL). 15: We suggest that clinicians use modafinil for the treatment of hypersomnia secondary to Parkinson's disease in adults. (CONDITIONAL). 16: We suggest that clinicians use sodium oxybate for the treatment of hypersomnia secondary to Parkinson's disease in adults. (CONDITIONAL). 17: We suggest that clinicians use armodafinil for the treatment of hypersomnia secondary to traumatic brain injury in adults. (CONDITIONAL). 18: We suggest that clinicians use modafinil for the treatment of hypersomnia secondary to traumatic brain injury in adults. (CONDITIONAL). 19: We suggest that clinicians use modafinil for the treatment of hypersomnia secondary to myotonic dystrophy in adults. (CONDITIONAL). 20: We suggest that clinicians use modafinil for the treatment of hypersomnia secondary to multiple sclerosis in adults. (CONDITIONAL). 21: We suggest that clinicians use modafinil for the treatment of narcolepsy in pediatric patients. (CONDITIONAL). 22: We suggest that clinicians use sodium oxybate for the treatment of narcolepsy in pediatric patients. (CONDITIONAL). CITATION: Maski K, Trotti LM, Kotagal S, et al. Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2021;17(9):1881-1893.

Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment.

INTRODUCTION: This systematic review provides supporting evidence for the accompanying clinical practice guideline on the treatment of central disorders of hypersomnolence in adults and children. The review focuses on prescription medications with U.S. Food & Drug Administration approval and nonpharmacologic interventions studied for the treatment of symptoms caused by central disorders of hypersomnolence. METHODS: The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine to perform a systematic review. Randomized controlled trials and observational studies addressing pharmacological and nonpharmacological interventions for central disorders of hypersomnolence were identified. Statistical analyses were performed to determine the clinical significance of all outcomes. Finally, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was used to assess the evidence for the purpose of making specific treatment recommendations. RESULTS: The literature search identified 678 studies; 144 met the inclusion criteria and 108 provided data suitable for statistical analyses. Evidence for the following interventions is presented: armodafinil, clarithromycin, clomipramine, dextroamphetamine, flumazenil, intravenous immune globulin (IVIG), light therapy, lithium, l-carnitine, liraglutide, methylphenidate, methylprednisolone, modafinil, naps, pitolisant, selegiline, sodium oxybate, solriamfetol, and triazolam. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations. CITATION: Maski K, Trotti LM, Kotagal S, et al. Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(9):1895-1945.

Sleep is essential to health: an American Academy of Sleep Medicine position statement.

CITATION: Sleep is a biological necessity, and insufficient sleep and untreated sleep disorders are detrimental for health, well-being, and public safety. Healthy People 2030 includes several sleep-related objectives with the goal to improve health, productivity, well-being, quality of life, and safety by helping people get enough sleep. In addition to adequate sleep duration, healthy sleep requires good quality, appropriate timing, regularity, and the absence of sleep disorders. It is the position of the American Academy of Sleep Medicine (AASM) that sleep is essential to health. There is a significant need for greater emphasis on sleep health in education, clinical practice, inpatient and long-term care, public health promotion, and the workplace. More sleep and circadian research is needed to further elucidate the importance of sleep for public health and the contributions of insufficient sleep to health disparities. CITATION: Ramar K, Malhotra RK, Carden KA, et al. Sleep is essential to health: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2021;17(10):2115-2119.

Oxygen Therapy in Sleep-Disordered Breathing.

Sleep-disordered breathing (SDB) is highly prevalent in adults and leads to significant cardiovascular and neurologic sequelae. Intermittent hypoxia during sleep is a direct consequence of SDB. Administration of nocturnal supplemental oxygen (NSO) has been used as a therapeutic alternative to positive airway pressure (PAP) in SDB. NSO significantly improves oxygen saturation in OSA but is inferior to PAP in terms of reducing apnea severity and may prolong the duration of obstructive apneas. The effect of NSO on daytime sleepiness remains unclear, but NSO may improve physical function-related quality of life in OSA. Its effects on BP reduction remain inconclusive. The effects of NSO vs PAP in OSA with comorbid COPD (overlap syndrome) are unknown. NSO is effective in reducing central sleep apnea related to congestive heart failure; however, its impact on mortality and cardiovascular clinical outcomes are being investigated in an ongoing clinical trial. In conclusion, studies are inconclusive or limited regarding clinical outcomes with oxygen therapy compared with sham or PAP therapy in patients with OSA and overlap syndrome. Oxygen does mitigate central sleep apnea. This review examines the crucial knowledge gaps and suggests future research priorities to clarify the effects of optimal dose and duration of NSO, alone or in combination with PAP, on cardiovascular, sleep, and cognitive outcomes.

Opioids and sleep.

PURPOSE OF REVIEW: Summarize the effects of opioids on sleep including sleep architecture, sleep disordered breathing (SDB) and restless legs syndrome. RECENT FINDINGS: Opioids are associated with the development of central sleep apnea (CSA) and ataxic breathing. Recent reports suggest that adaptive servo-ventilation may be an effective treatment for CSA associated with opioids. SUMMARY: Opioids have multiple effects on sleep, sleep architecture and SDB. Although originally described with methadone use, most commonly used opioids have also been shown to affect sleep. In patients on chronic methadone, sleep architecture changes include decreases in N3 and REM sleep. However, in patients with chronic nonmalignant pain, opioids improve sleep quality and sleep time. Opioids, generally at a morphine equivalent dose more than 100 mg/day, are associated with an increased incidence of CSA and ataxic breathing as well as obstructive sleep apnea. Other risk factors may include concomitant use of other medications such as antidepressants, gabapentinoids and benzodiazepines. Opioid-induced CSA can be potentially treated with adaptive servo-ventilation. Finally, opioids are a potential therapeutic option for restless legs syndrome unresponsive to dopamine agonists and other medications. However, use in patients with restless legs syndrome should proceed with caution, taking into account the risk for dependence and development of SDB.

Strategies to improve patient care for obstructive sleep apnea: a report from the American Academy of Sleep Medicine Sleep-Disordered Breathing Collaboration Summit.

NONE: In Chicago, Illinois, on Saturday, November 10, 2018, the American Academy of Sleep Medicine hosted 35 representatives from 14 medical societies, nurse practitioner associations and patient advocacy groups for a one-day Sleep-Disordered Breathing Collaboration Summit to discuss strategies to improve the diagnosis and treatment of obstructive sleep apnea. This report provides a brief synopsis of the meeting, identifies current challenges, and highlights potential opportunities for ongoing collaboration.

Daylight saving time: an American Academy of Sleep Medicine position statement.

None: The last several years have seen intense debate about the issue of transitioning between standard and daylight saving time. In the United States, the annual advance to daylight saving time in spring, and fall back to standard time in autumn, is required by law (although some exceptions are allowed under the statute). An abundance of accumulated evidence indicates that the acute transition from standard time to daylight saving time incurs significant public health and safety risks, including increased risk of adverse cardiovascular events, mood disorders, and motor vehicle crashes. Although chronic effects of remaining in daylight saving time year-round have not been well studied, daylight saving time is less aligned with human circadian biology-which, due to the impacts of the delayed natural light/dark cycle on human activity, could result in circadian misalignment, which has been associated in some studies with increased cardiovascular disease risk, metabolic syndrome and other health risks. It is, therefore, the position of the American Academy of Sleep Medicine that these seasonal time changes should be abolished in favor of a fixed, national, year-round standard time.

Sleep, fatigue and burnout among physicians: an American Academy of Sleep Medicine position statement.

None: Physician burnout is a serious and growing threat to the medical profession and may undermine efforts to maintain a sufficient physician workforce to care for the growing and aging patient population in the United States. Burnout involves a host of complex underlying associations and potential for risk. While prevalence is unknown, recent estimates of physician burnout are quite high, approaching 50% or more, with midcareer physicians at highest risk. Sleep deprivation due to shift-work schedules, high workload, long hours, sleep interruptions, and insufficient recovery sleep have been implicated in the genesis and perpetuation of burnout. Maladaptive attitudes regarding sleep and endurance also may increase the risk for sleep deprivation among attending physicians. While duty-hour restrictions have been instituted to protect sleep opportunity among trainees, virtually no such effort has been made for attending physicians who have completed their training or practicing physicians in nonacademic settings. It is the position of the American Academy of Sleep Medicine that a critical need exists to evaluate the roles of sleep disruption, sleep deprivation, and circadian misalignment in physician well-being and burnout. Such evaluation may pave the way for the development of effective countermeasures that promote healthy sleep, with the goal of reducing burnout and its negative impacts such as a shrinking physician workforce, poor physician health and functional outcomes, lower quality of care, and compromised patient safety.

Artificial intelligence in sleep medicine: an American Academy of Sleep Medicine position statement.

None: Sleep medicine is well positioned to benefit from advances that use big data to create artificially intelligent computer programs. One obvious initial application in the sleep disorders center is the assisted (or enhanced) scoring of sleep and associated events during polysomnography (PSG). This position statement outlines the potential opportunities and limitations of integrating artificial intelligence (AI) into the practice of sleep medicine. Additionally, although the most apparent and immediate application of AI in our field is the assisted scoring of PSG, we propose potential clinical use cases that transcend the sleep laboratory and are expected to deepen our understanding of sleep disorders, improve patient-centered sleep care, augment day-to-day clinical operations, and increase our knowledge of the role of sleep in health at a population level.

Chronic Opioid Therapy and Sleep: An American Academy of Sleep Medicine Position Statement.

None: There is a complex relationship among opioids, sleep and daytime function. Patients and medical providers should be aware that chronic opioid therapy can alter sleep architecture and sleep quality as well as contribute to daytime sleepiness. It is also important for medical providers to be cognizant of other adverse effects of chronic opioid use including the impact on respiratory function during sleep. Opioids are associated with several types of sleep-disordered breathing, including sleep-related hypoventilation, central sleep apnea (CSA), and obstructive sleep apnea (OSA). Appropriate screening, diagnostic testing, and treatment of opioid-associated sleep-disordered breathing can improve patients' health and quality of life. Collaboration among medical providers is encouraged to provide high quality, patient-centered care for people who are treated with chronic opioid therapy.

Clinical Use of a Home Sleep Apnea Test: An Updated American Academy of Sleep Medicine Position Statement.

ABSTRACT: The diagnosis and effective treatment of obstructive sleep apnea (OSA) in adults is an urgent health priority. It is the position of the American Academy of Sleep Medicine (AASM) that only a medical provider can diagnose medical conditions such as OSA and primary snoring. Throughout this statement, the term "medical provider" refers to a licensed physician and any other health care professional who is licensed to practice medicine in accordance with state licensing laws and regulations. A home sleep apnea test (HSAT) is an alternative to polysomnography for the diagnosis of OSA in uncomplicated adults presenting with signs and symptoms that indicate an increased risk of moderate to severe OSA. It is also the position of the AASM that: the need for, and appropriateness of, an HSAT must be based on the patient's medical history and a face-to-face examination by a medical provider, either in person or via telemedicine; an HSAT is a medical assessment that must be ordered by a medical provider to diagnose OSA or evaluate treatment efficacy; an HSAT should not be used for general screening of asymptomatic populations; diagnosis, assessment of treatment efficacy, and treatment decisions must not be based solely on automatically scored HSAT data, which could lead to sub-optimal care that jeopardizes patient health and safety; and the raw data from the HSAT device must be reviewed and interpreted by a physician who is either board-certified in sleep medicine or overseen by a board-certified sleep medicine physician.

Polysomnography for Obstructive Sleep Apnea Should Include Arousal-Based Scoring: An American Academy of Sleep Medicine Position Statement.

ABSTRACT: The diagnostic criteria for obstructive sleep apnea (OSA) in adults, as defined in the International Classification of Sleep Disorders, Third Edition, requires an increased frequency of obstructive respiratory events demonstrated by in-laboratory, attended polysomnography (PSG) or a home sleep apnea test (HSAT). However, there are currently two hypopnea scoring criteria in The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications (AASM Scoring Manual). This dichotomy results in differences among laboratory reports, patient treatments and payer policies. Confusion occurs regarding recognizing and scoring "arousal-based respiratory events" during OSA testing. "Arousal-based scoring" recognizes hypopneas associated with electroencephalography-based arousals, with or without significant oxygen desaturation, when calculating an apnea-hypopnea index (AHI), or it includes respiratory effort-related arousals (RERAs), in addition to hypopneas and apneas, when calculating a respiratory disturbance index (RDI). Respiratory events associated with arousals, even without oxygen desaturation, cause significant, and potentially dangerous, sleep apnea symptoms. During PSG, arousal-based respiratory scoring should be performed in the clinical evaluation of patients with suspected OSA, especially in those patients with symptoms of excessive daytime sleepiness, fatigue, insomnia, or other neurocognitive symptoms. Therefore, it is the position of the AASM that the RECOMMENDED AASM Scoring Manual scoring criteria for hypopneas, which includes diminished airflow accompanied by either an arousal or ≥ 3% oxygen desaturation, should be used to calculate the AHI. If the ACCEPTABLE AASM Scoring Manual criteria for scoring hypopneas, which includes only diminished airflow plus ≥ 4% oxygen desaturation (and does not allow for arousal-based scoring alone), must be utilized due to payer policy requirements, then hypopneas as defined by the RECOMMENDED AASM Scoring Manual criteria should also be scored. Alternatively, the AASM Scoring Manual includes an option to report an RDI which also provides an assessment of the sleep-disordered breathing that results in arousal from sleep. Furthermore, given the inability of most HSAT devices to capture arousals, a PSG should be performed in any patient with an increased risk for OSA whose HSAT is negative. If the PSG yields an AHI of 5 or more events/h, or if the RDI is greater than or equal to 5 events/h, then treatment of symptomatic patients is recommended to improve quality of life, limit neurocognitive symptoms, and reduce accident risk.

Consumer Sleep Technology: An American Academy of Sleep Medicine Position Statement.

ABSTRACT: Consumer sleep technologies (CSTs) are widespread applications and devices that purport to measure and even improve sleep. Sleep clinicians may frequently encounter CST in practice and, despite lack of validation against gold standard polysomnography, familiarity with these devices has become a patient expectation. This American Academy of Sleep Medicine position statement details the disadvantages and potential benefits of CSTs and provides guidance when approaching patient-generated health data from CSTs in a clinical setting. Given the lack of validation and United States Food and Drug Administration (FDA) clearance, CSTs cannot be utilized for the diagnosis and/or treatment of sleep disorders at this time. However, CSTs may be utilized to enhance the patient-clinician interaction when presented in the context of an appropriate clinical evaluation. The ubiquitous nature of CSTs may further sleep research and practice. However, future validation, access to raw data and algorithms, and FDA oversight are needed.

Medical Cannabis and the Treatment of Obstructive Sleep Apnea: An American Academy of Sleep Medicine Position Statement.

ABSTRACT: The diagnosis and effective treatment of obstructive sleep apnea (OSA) in adults is an urgent health priority. Positive airway pressure (PAP) therapy remains the most effective treatment for OSA, although other treatment options continue to be explored. Limited evidence citing small pilot or proof of concept studies suggest that the synthetic medical cannabis extract dronabinol may improve respiratory stability and provide benefit to treat OSA. However, side effects such as somnolence related to treatment were reported in most patients, and the long-term effects on other sleep quality measures, tolerability, and safety are still unknown. Dronabinol is not approved by the United States Food and Drug Administration (FDA) for treatment of OSA, and medical cannabis and synthetic extracts other than dronabinol have not been studied in patients with OSA. The composition of cannabinoids within medical cannabis varies significantly and is not regulated. Synthetic medical cannabis may have differential effects, with variable efficacy and side effects in the treatment of OSA. Therefore, it is the position of the American Academy of Sleep Medicine (AASM) that medical cannabis and/or its synthetic extracts should not be used for the treatment of OSA due to unreliable delivery methods and insufficient evidence of effectiveness, tolerability, and safety. OSA should be excluded from the list of chronic medical conditions for state medical cannabis programs, and patients with OSA should discuss their treatment options with a licensed medical provider at an accredited sleep facility. Further research is needed to understand the functionality of medical cannabis extracts before recommending them as a treatment for OSA.