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Editorials Point and Counterpoint
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POINT:
Does Laboratory Polysomnography Yield Better Outcomes Than Home Sleep Testing? Yes Allan I. Pack, MBChB, PhD; Philadelphia, PA
AHI 5 apnea-hypopnea index; APAP 5 autotitrating positive airway pressure; HST 5 home sleep testing; PAP 5 positive airway pressure; PCP 5 primary care physician; PSG 5 polysomnography
ABBREVIATIONS:
One of the things that has challenged sleep medicine is the debate about which diagnostic study to use for the diagnosis of OSA. It is as if there was only one strategy possible that is appropriate for all patients. Diagnosis is, however, only one part, and indeed a relatively small part, of the total strategy for care. There is little doubt that home sleep studies can be used for the diagnosis of OSA. This is supported by randomized trials1-3 comparing the outcomes of an in-laboratory pathway for diagnosis and CPAP titration to an out-oflaboratory pathway. These studies focused on outcomes of care as advocated by a trisociety report.4 These studies were similar in design using a parallel group strategy to compare outcomes of an in-laboratory pathway to that from an out-of-laboratory home pathway. The in-laboratory pathway used the standard laboratory polysomnography followed by technologist-directed CPAP titration. The out-of-laboratory pathway used a home sleep study without EEG followed by autoadjust CPAP titration for several nights at home before being switched to fixed CPAP. Outcomes assessed at follow-up include changes in the Epworth Sleepiness Score,5 the AFFILIATIONS: From the Division of Sleep Medicine/Department of Medicine and Center for Sleep and Circadian Neurobiology, Perelman School of Medicine at the University of Pennsylvania. FINANCIAL/NONFINANCIAL DISCLOSURES: The author has reported to CHEST the following conflicts of interest: Dr Pack holds an endowed chair, the Miclot Chair, that was funded by a donation from the Respironics Foundation. CORRESPONDENCE TO: Allan I. Pack, MBChB, PhD, Perelman School of Medicine at the University of Pennsylvania, Ste 2100, 125 S 31st St, Philadelphia, PA 19104-3403; e-mail:
[email protected] © 2015 AMERICAN COLLEGE OF CHEST PHYSICIANS. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details. DOI: 10.1378/chest.15-0477
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Functional Outcomes of Sleepiness Questionnaire,6 and CPAP adherence. Outcomes at 6 weeks in one study1 and 3 months in two others2,3 were essentially identical between the in-laboratory and in-home pathways. Kuna et al2 found that CPAP adherence was higher but not significantly so in the in-home pathway while Rosen et al3 did find significantly higher CPAP adherence in the in-home pathway compared with the in-laboratory pathway. These studies, however, had other common characteristics. They were in patients with high pretest probability of disease. Indeed, one might ask whether in this group any study was required for diagnosis. Could this subgroup of patients with OSA simply have been started on autoadjust CPAP? Successful outcomes of this straight-to-treatment approach in a minority of patients with OSA have been documented.7 Management of patients in both studies was not in a primary care setting but by experts in comprehensive sleep centers. While these are the common characteristics of the studies, insurance companies have built policies that imply that the results of these studies are generalizable, that is, they can be applied to any patient with suspected OSA whatever the pretest probability of disease. Moreover, they assume that any physician with or without specific training can manage these patients. Both assumptions are false. First, let us consider the idea that home studies are appropriate for all. Masa et al,8 in an elegant study, compared therapeutic decisions based on the results of home studies or in-laboratory polysomnograms in patients with a variety of severities of OSA. They used an interesting design to address whether, in individual patients, the same therapeutic decision was made with data from in-laboratory polysomnograms and from home studies. Each patient had both a home study and laboratory study (order randomized) at baseline and 1 month later. Thus, each subject had four studies: two laboratory studies and two home. Data from these studies, together with clinical information, were given to independent physicians who decided whether to prescribe CPAP or not. Not surprisingly, there was high concordance of decision-making (. 90%) for data from the two in-laboratory studies. However, while in those with severe disease (apnea hypopnea index . 30 events/h),
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there is similar high concordance between decisions from laboratory and home studies, at more moderate disease (eg, apnea hypopnea index 5 20) concordance drops to around 80%. Thus, individuals who would be treated on the basis of a laboratory study would not be based on results of a home study. Data from the study of Masa et al9 were also used to develop an economic analysis of the costs of a purely in-laboratory pathway for diagnosis compared with a purely home pathway and to a hybrid model. Even allowing for repeat in-laboratory studies for patients in the “gray zone” based on home studies, the home study pathway proved cheaper.
direct management of OSA. They are overwhelmed doing what they do and keeping up with quality metrics. There seems little point in doing sleep studies if there are no committed, trained practitioners to manage the condition once diagnosed. It seems unlikely that this fragmented model of care with diagnosis by PCP and management by durable medical equipment companies will lead to good outcomes although this has not been studied. Unfortunately, tracking outcomes has not been a standard for accreditation of comprehensive sleep centers and we do not know the outcomes that are achieved by more conventional approaches.
But other economic analyses have come to different conclusions.10,11 Since home studies will miss patients with the disease, there are downstream costs of not treating these patients as a result of the multiple consequences of untreated OSA. Such economic analyses, however, are dependent on assumptions made and hence are not definitive.12 Nevertheless, they do indicate that simply looking at costs of the diagnostic test is a short-sighted strategy. One needs to consider the economic benefits of identifying and treating these patients and the costs of misdiagnosis. Moreover, what is the point of a test if individuals do not get effectively treated?
Ultimately, the debate about which test gives the best outcomes is not the most important question. It is what happens after the test that matters the most. Sleep medicine has never been a diagnostic discipline; it is a chronic care management discipline. This was identified by the Institute of Medicine committee in 2005; Recommendation 9.2 in the report published in 2006 stated, “Sleep laboratories should be part of accredited sleep centers, the latter to include long-term strategies for patient care and chronic disease management. Accreditation criteria should expand beyond a primary focus on diagnostic testing to emphasize treatment, long-term patient care, and chronic disease management strategies.”16
Investigations of use of home studies for OSA diagnosis have largely been conducted in patients with high pretest probability of OSA being evaluated in sleep centers as shown by a recent meta-analysis.13 Thus, the authors of this meta-analysis considered that in-laboratory polysomnography remains the “cornerstone of diagnosis of patients suspected of having comorbid sleep disorders, unstable medical conditions or complex sleep-disordered breathing”.13 Insurers now recognize this and will allow laboratory studies for patients with COPD and those who are taking opiates or have a serum bicarbonate ⱖ 28 mEq/L (a likely indication of obesity-hypoventilation).14 Thus, we can conclude that home studies are not appropriate for all. Insurers and other payors now allow primary care physicians (PCPs) and other physicians to directly order home sleep studies and manage patients with OSA. The management is provided by durable medical equipment companies who prescribe CPAP. While there are studies showing that PCPs can manage OSA,15 there is no evidence that this is broadly true. Certainly PCPs have the intellectual capacity to do so. This is not the question. The question is whether they have the bandwidth and infrastructure to do so. A large number of primary care practices in our health-care system indicate that they cannot take on
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We now have new technology that allows remote monitoring not only of CPAP use but also efficacy of therapy and mask leak. Providing this information to the patients themselves with a patient portal enhances CPAP compliance.17 Thus, the question that matters most to patients is what are the best strategies to adopt to enhance CPAP compliance and efficacy of therapy?
References 1. Berry RB, Hill G, Thompson L, McLaurin V. Portable monitoring and autotitration versus polysomnography for the diagnosis and treatment of sleep apnea. Sleep. 2008;31(10):1423-1431. 2. Kuna ST, Gurubhagavatula I, Maislin G, et al. Noninferiority of functional outcome in ambulatory management of obstructive sleep apnea. Am J Respir Crit Care Med. 2011;183(9):1238-1244. 3. Rosen CL, Auckley D, Benca R, et al. A multisite randomized trial of portable sleep studies and positive airway pressure autotitration versus laboratory-based polysomnography for the diagnosis and treatment of obstructive sleep apnea: the HomePAP study. Sleep. 2012;35(6):757-767. 4. Chesson AL Jr, Berry RB, Pack A; American Academy of Sleep Medicine; American Thoracic Society ; American College of Chest Physicians. 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. 5. Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep. 1991;14(6):540-545. 6. Weaver TE, Laizner AM, Evans LK, et al. An instrument to measure functional status outcomes for disorders of excessive sleepiness. Sleep. 1997;20(10):835-843.
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7. Mulgrew AT, Fox N, Ayas NT, Ryan CF. Diagnosis and initial management of obstructive sleep apnea without polysomnography: a randomized validation study. Ann Intern Med. 2007;146(3): 157-166. 8. Masa JF, Corral J, Pereira R, et al; Spanish Sleep Network. Therapeutic decision-making for sleep apnea and hypopnea syndrome using home respiratory polygraphy: a large multicentric study. Am J Respir Crit Care Med. 2011;184(8):964-971. 9. Masa JF, Corral J, Sanchez de Cos J, et al. Effectiveness of three sleep apnea management alternatives. Sleep. 2013;36(12):1799-1807. 10. Chervin RD, Murman DL, Malow BA, Totten V. Cost-utility of three approaches to the diagnosis of sleep apnea: polysomnography, home testing, and empirical therapy. Ann Intern Med. 1999;130(6):496-505. 11. Pietzsch JB, Garner A, Cipriano LE, Linehan JH. An integrated health-economic analysis of diagnostic and therapeutic strategies in the treatment of moderate-to-severe obstructive sleep apnea. Sleep. 2011;34(6):695-709. 12. Ayas NT, Pack A, Marra C. The demise of portable monitoring to diagnose OSA? Not so fast! Sleep. 2011;34(6):691-692. 13. El Shayeb M, Topfer LA, Stafinski T, Pawluk L, Menon D. Diagnostic accuracy of level 3 portable sleep tests versus level 1 polysomnography for sleep-disordered breathing: a systematic review and meta-analysis. CMAJ. 2014;186(1):E25-E51. 14. Mokhlesi B, Tulaimat A, Faibussowitsch I, Wang Y, Evans AT. Obesity hypoventilation syndrome: prevalence and predictors in patients with obstructive sleep apnea. Sleep Breath. 2007;11(2): 117-124. 15. Chai-Coetzer CL, Antic NA, Rowland LS, et al. Primary care vs specialist sleep center management of obstructive sleep apnea and daytime sleepiness and quality of life: a randomized trial. JAMA. 2013;309(10):997-1004. 16. Colten HR, Altevogt BM. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington, DC: The National Academies Press; 2006. 17. Kuna ST, Shuttleworth D, Chi L, et al. Web-based access to positive airway pressure usage with or without an initial financial incentive improves treatment use in patients with obstructive sleep apnea [published online ahead of print January 12, 2015]. Sleep.
COUNTERPOINT:
Does Laboratory Polysomnography Yield Better Outcomes Than Home Sleep Testing? No Neil Freedman, MD, FCCP; Bannockburn, IL
It has been almost 7 years since the Centers for Medicare and Medicaid Services approved home sleep testing (HST) for the diagnosis of OSA in adults. Since the initial approval of HST, there have been several peer-reviewed AFFILIATIONS: From the Division of Pulmonary, Critical Care, Allergy and Immunology, NorthShore University Health System. FINANCIAL/NONFINANCIAL DISCLOSURES: The author has reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. CORRESPONDENCE: Neil Freedman, MD, FCCP, 2151 Waukegan Rd, Bannockburn, IL 60015; e-mail:
[email protected] © 2015 AMERICAN COLLEGE OF CHEST PHYSICIANS. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details. DOI: 10.1378/chest.15-0479
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studies validating many different portable diagnostic devices as well as numerous randomized controlled trials demonstrating similar outcomes when comparing an ambulatory approach that incorporates HST to a management strategy utilizing polysomnography (PSG) for diagnosis and determination of appropriate CPAP therapy.1-7 Yet, despite advancements in technology and a growing body of outcome data supporting the use of HST in appropriate patient populations, many clinicians have not willingly adopted HST as part of a standard strategy for the diagnosis and management of OSA.
PSG Compared With HST for the Diagnosis of OSA PSG has been considered the gold standard for the diagnosis of OSA, as for many years there had been few alternatives. While many critics argue that the sensitivity and specificity of HST for assessing OSA are inferior to that of PSG, PSG is far from perfect for diagnosing OSA or defining its severity. Estimates of the sensitivity of one night of PSG to detect an apnea-hypopnea index (AHI) . 5 in patients with OSA range between 75% and 88%.8 The less-than-optimal sensitivity and specificity are due to several factors including disease-related night-to-night variability, the patient population being tested, number and types of parameters being measured, and the differences in disease definition. Specifically, the sensitivity and specificity for both PSG and HST depend on the hypopnea definition used to define sleep-disordered breathing events as well as the threshold AHI used to define OSA. Proponents of PSG also contend that HST results in higher failure rates and greater need for repeat testing when compared with PSG. While there are no standard definitions for failure vs success with HST, failure rates in the literature range from 1% to as high as 20% depending on the study and type of device. Aside from a minimum of 6 h of recording time that is typically required for reimbursement for PSG, there are no standard definitions for failure vs success for PSG. Thus, it is difficult to accurately determine whether HST actually results in higher failure rates when compared with PSG in clinical practice. Even in cases where an HST is not successful, the cost of repeating an HST is still less than the cost of a single PSG. When comparing HST devices as a group to PSG for the diagnosis of OSA, several issues need to be acknowledged. First, many of these devices use an array of technologies that incorporate alternative physiologic measurements and proprietary algorithms to define and quantify
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