1. When is ambulatory monitoring for OSA indicated ?
Robert P. Skomro MD, FRCPC, D.ABSM
Associate Professor
Division of Respiratory, Critical Care and Sleep Medicine
University of Saskatchewan
Saskatoon 1

2. AASM Classification
Level I: Standard polysomnography: Minimal requirements include recording of EEG, EOG, chin EMG, ECG, airflow, respiratory effort, and oxygen saturation. Body position must be documented or objectively measured. Trained personnel must be in constant attendance and able to intervene. Leg movement recording is desirable but optional.
Level II: Comprehensive portable polysomnography: Same as for level I, except heart rate instead of ECG is acceptable, and having trained personnel present and able to intervene is not required for all studies.
Level III: Modified portable sleep apnea testing: Minimum requirements include recording of ventilation (at least 2 channels of respiratory movement, or respiratory movement and airflow), ECG or heart rate, and oxygen saturation. Personnel are needed for preparation, but the ability to intervene is not required for all studies
Level IV: Continuous (single or dual) bioparameter recording: Only 1 or 2 physiologic variables need be recorded. The ability to intervene is not required. 2

3. Obesity Trends* Among U.S. Adults 1990, 1995, 2005
(*BMI 30, or about 30 lbs overweight for 5’4” person)
1990
1995
2005 3

4. OSA PREVALENCE Composite of Wisconsin, Pennsylvania, and Spain:
1/ 5 adults with mild OSA, 1/ 15 at least moderate OSA
Young et al Am J Respir Crit Care Med 2002;165:
OSA AFFECTS 2-3% OF CHILDREN 4

5. OSA incidence
Flemons et al estimate that 5.1% of adults will develop OSA over 8 years:
0.6% per year
OSA incidence alone will require 600 studies per 100,000 population per year
What about repeat studies ? 5

6. AASM/ACCP/ATS Review Results (Chest Oct.2003)
Type 3 in-home unattended- 4 studies
Data loss 3-18%
Sensitivities %
Specificities 58-93%
False positives 2-31%,false negatives 0-45%
LR , LR
Adapted from B.Boehlecke 6

7. AASM/ACCP/ATS Review Results
Type 3 in-laboratory - 9 studies
Data loss 3-9%
Define TP by PSG (AHI >15 when reported)
Best sensitivities %
Best specificities %
False positives 0-22%,false negatives 0-21%
LR , LR
Adapted from B.Boehlecke 7

8. AASM/ACCP/ATS Review Summary
Type 3 devices
“Type 3 monitors have utility to both reduce and increase the probability that a patient may have sleep apnea in the attended setting. The utility in the unattended setting is not as well-established”. (Page1573) 8

9. Executive Summary (Am J Respir Crit Care Med)
Type 3 monitors for use in an unattended setting :
Not recommended to decrease or increase the probability that the patient has an AHI >15
Not recommended for use to rule in and rule out OSA 9

10. Position of CMS - USA
“ Effectiveness of Portable Monitoring Devices of diagnosing Obstructive sleep apnea: update and systematic review “ - September 1,2004
Centers for Medicare and Medicaid Services
Decision regarding CPAP coverage
“The polysomnography must be performed in a facility - based sleep study laboratory, and not in the home or in a mobile facility”.
Adapted from B.Boehlecke 10

11. Update for Agency Health Care Research and Quality September 2004
12 studies reviewed in detail
Simultaneous in-lab comparison only
Type 3: 2 studies (fair and poor quality ratings)
Type 4: 5 studies (1 fair, 4 poor quality ratings)
Both in-lab and home comparisons
Type 3: 2 studies (good and fair/poor quality)
Type 4: 1 study (fair quality rating)
Only in-home studies compared to PSG
Type 4: 2 studies (fair and poor quality ratings)
Adapted from B.Boehlecke 11

12. Reasons for lack of acceptance of level III home monitoring
Technical:
Lack of EEG monitoring
AHI cannot be established as sleep time is unknown
Failure rate of home monitoring
A large variety of home monitors – lack of standardization
Inability to perform CPAP titration
Scoring – are the automatic scoring systems reliable ? 12

13. Reasons for lack of acceptance of level III home monitoring
Scientific:
Level of evidence
Lack of outcome studies
Poor external validity – studies not including patients with heart and lung problems, children, women, elderly 13

14. Reasons for lack of acceptance of level III home monitoring
Other
Cost effectiveness of home monitoring questioned
Implementation depends on the availability and access to sleep labs in the area
Fees: who pays, how much ?
Quality control 14

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17. Mulgrew et al. Study results
Primary outcome:
AHI at 3 months
Secondary:
ESS, SAQLI, CPAP adherence 17

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20. AAMS 2007 guidelines
PM FOR THE DIAGNOSIS OF OSA SHOULD BE PERFORMED ONLY IN CONJUNCTION WITH A COMPREHENSIVE SLEEP EVALUATION.
CLINICAL SLEEP EVALUATIONS USING PM MUST BE SUPERVISED BY A PRACTITIONER WITH BOARD CERTIFICATION IN SLEEP MEDICINE OR AN INDIVIDUAL WHO FULFILLS THE ELIGIBILITY CRITERIA FOR THE SLEEP MEDICINE CERTIFICATION EXAMINATION.
IN THE ABSENCE OF A COMPREHENSIVE SLEEP EVALUATION, THERE IS NO INDICATION FOR THE USE OF PM. 20

21. AAMS 2007 guidelines
PROVIDED THAT THE RECOMMENDATIONS OF 1.1 HAVE BEEN SATISFIED, PM MAY BE USED AS AN ALTERNATIVE TO POLYSOMNOGRAPHY (PSG) FOR THE DIAGNOSIS OF OSA IN PATIENTS WITH A HIGH PRETEST PROBABILITY OF MODERATE TO SEVERE OSA.
PM SHOULD NOT BE USED IN THE PATIENT GROUPS DESCRIBED IN 1.2.1, 1.2.2, AND (THOSE WITH COMORBIDITIES, OTHER SLEEP DISORDERS, OR FOR SCREENING). 21

22. PM MAY BE INDICATED FOR THE DIAGNOSIS OF OSA IN PATIENTS
AAMS 2007 guidelines
PM is not appropriate for general screening of asymptomatic populations.
PM MAY BE INDICATED FOR THE DIAGNOSIS OF OSA IN PATIENTS
FOR WHOM IN-LABORATORY PSG IS NOT POSSIBLE BY VIRTUE OF IMMOBILITY, SAFETY, OR CRITICAL ILLNESS.
PM MAY BE INDICATED TO MONITOR THE RESPONSE TO NON-CPAP
TREATMENTS FOR OBSTRUCTIVE SLEEP APNEA, INCLUDING ORAL APPLIANCES, UPPER AIRWAY SURGERY, AND WEIGHT LOSS 22

23. AT A MINIMUM, THE PMS MUST RECORD
AAMS 2007 guidelines
AT A MINIMUM, THE PMS 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. 23

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25. Canadian Thoracic Society OSA Guidelines
1. Level I (complete laboratory polysomnography) remains the accepted standard for evaluation of SDB and is the test of choice.
2. Level II (full ambulatory polysomnography) and level III portable monitoring (multichannel cardiorespiratory recording devices) play a useful role in improving access to the diagnosis of SDB. 25

26. 3. Level II and III studies can be used to confirm the
diagnosis of OSAHS in patients with a moderate to high pretest probability of this disorder, but are of more limited use in patients with co-morbid disease and for the diagnosis of other forms of SDB.
4.Studies using oximetry alone may have a role in the initial assessment of SDB, however, their significant limitations in distinguishing different types of SDB must be fully appreciated before using them to make diagnostic and therapeutic decisions 26

27. Canadian Thoracic Society OSA Guidelines
5. The level of experience and training available to interpret the results of sleep monitoring is as important as the type of sleep monitoring.
6. All sleep monitoring should be conducted with an appropriate quality assurance program and interpreted by a physician trained in the diagnosis of SDB. 27

28. CMMS CPAP Coverage Decision
Center for Medicare and Medicaid Services – USA
March 13, 2008 28

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30. CMMS 2008
CPAP for adults is covered when diagnosed using a clinical evaluation and a positive:
a. polysomnography (PSG) performed in a sleep laboratory; or
b. unattended home sleep monitoring device of Type II; or
c. unattended home sleep monitoring device of Type III; or
d. unattended home sleep monitoring device of Type IV, measuring at least three channels 30

31. CMMS decision
Coverage of CPAP is initially limited to a 12 week period for beneficiaries diagnosed with OSA as subsequently described.
CPAP is subsequently covered for those beneficiaries diagnosed with OSA whose OSA improved as a result of CPAP during this 12 week period 31

32. AHI or RDI greater than or equal to 15 events per hour, or
CMMS 2008
AHI or RDI greater than or equal to 15 events per hour, or
AHI or RDI greater than or equal to 5 and less than or equal to 14 events per hour with documented
symptoms of excessive daytime sleepiness, impaired cognition, mood disorders or insomnia, or
documented hypertension, ischemic heart disease, or history of stroke. 32

33. 33

34. Berry et al.
Randomised to home diagnosis and therapy using Peripheral Arterial Tonometry device and auto-CPAP or in-lab PSG
Primary outcome – CPAP adherence at 6 weeks
Secondary outcomes: ESS, FOSQ
No difference in outcomes 34

35. 35

36. Antic NA et al.
1427 screened
193 patients with moderate-to-severe pre- test probability of OSA based on oximetry
Randomised to
Nurse-driven care: auto CPAP + fixed CPAP
In-lab PSG X 2 supervised by sleep medicine physician
Main outcome: ESS at 3 months 36

37. Antic NA et al. At 3 months there were similar decreases in ESS
4.02 vs. 4.15; difference, -0.13; 95% confidence interval: -1.52, 1.25
No difference in CPAP adherence
Nurse-driven care less expensive. 37

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43. Patients’ characteristics in RCT of Level III
Study
N enrolled/ N screened
Device used
Inclusion criteria
Mulgrew
2007
79/2135
Males 75-79%
Oximetry
ESS > 10, SACS > 15, ODI > 15
Berry
2008
106/ not specified
Males 90%
Watch Pad 100
ESS > 12, and 2 of: snoring, apnea, HTN.
Antic
2009
195/1427
Males – 72-76%
Oximetry,
ESS > 8, age 18-75, ODI > 27
Skomro
2010
102/270
Males 66%
Embletta
Two of :ESS > 10, apnea and snoring AND age > 18, 43

44. Patient selection for Level III
Evidence from 4 RCTs:
Moderate – high pretest probability of OSA
No comorbidities
Predominantly male
Very selected group: % 44

45. Evolution of diagnosis and treatment of OSA
1981
Diagnostic PSG + manual CPAP titration = 2 lab nights
Split-night PSG = 1 night
Diagnostic PSG + auto-CPAP in the lab = 2 nights ( but less technician time)
Diagnostic PSG + auto-CPAP at home = 1 night
Diagnostic HM ( in the lab) + auto-CPAP (at home) = 1 night
Diagnostic HM (at home ) + auto-CPAP (at home)
2011 45

46. Airflow -Nasal Pressure
Parameters for In-home Unattended Limited Channel Devices for the Diagnosis of OSA (Westbrook, J Clin Sleep Med April 15; 3(3): 318–320). – survey of 175 AASM members
SpO2
Ability to edit automated scoring or to fully manually score recordings
Airflow -Nasal Pressure
Detection and marking of periods of poor signal quality
Full disclosure recording
Signals needed to differentiate obstructive/central events
Pulse Rate
User defined event criteria
Head/Body Position
Respiratory Effort - Qualitative 46

47. Quality of the Validation of the In-home Unattended Limited Channel
Less than 10% failure rate
PSG criteria/parameters used to assess accuracy
In-home to PSG sensitivity > 0.9, specificity > 0.8
Clinical study - In-home vs. PSG: N> 100
Clinical study - portable device concurrent with PSG; N > 40 47

48. 48

49. CTS 2011 Update Evidence from 2 Systematic Reviews and 3 RCTs:
Level II, III, IV devices can be used to confirm the diagnosis of OSA in patients with moderate to high pretest probability of this disorder when integrated into a package of care that includes the appropriate level of physician and allied health professional expertise and the backup availability of PSG ( 1B) 49

50. CTS 2011
These devices should be used only with caution in patients with co-morbid diseases and for the diagnosis of other forms of SDB (2C)
The limitations of overnight oximetry in distinguishing between different types of SDB must be fully appreciated before they are used to make diagnostic and therapeutic decisions (1B) 50

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52. Home Study Potential Disadvantages
Data loss – in our center <10%.
Automated scoring not accurate
Indeterminate study results (esp. if separate thresholds for + and – used to increase sensitivity/specificity)
Can’t perform “split night” studies
Can’t determine sleep architecture/quality, freq or types of arousals, other abnormalities
Misdiagnoses esp. if co-morbid conditions present 52

53. Level III monitors - summary
Reasonable PPV for moderate and severe OSA
Poor NPV
Require a repeat in 5-15 %
Should not be used without proper assessment of pre-test probability of OSA
i.e by qualified sleep medicine consultant
Should not be applied to patients with comorbidites
Should be scored by a qualified technician and interpreted by a qualified sleep medicine physician 53

54. Future of diagnosis of OSA ?
Level III devices are already widely used in diagnosis of OSA in parts of Canada, USA, Europe
Current guidelines from AASM, CTS define their diagnostic role and limitations
Dissemination and implementation 54

55. The Sleep Well Program: In-Home Testing and Treatment for Obstructive Sleep Apnea55

56. - 18 – 65 years of age Inclusion criteria
Patient Selection
Inclusion criteria
- 18 – 65 years of age
- Epworth Sleepiness Scale > 10
- Berlin score
- BMI > 30
- Symptoms of snoring and apnea
- Ability to use home testing 56

57. Exclusion Criteria - Cardiac disease/CHF
Patient Selection
Exclusion Criteria
- Cardiac disease/CHF
- Respiratory disease, obesity hypoventilation
- Sleeping disorder
- Currently on CPAP, BiPAP or
supplemental O2
- Safety sensitive occupation
- Upper airway or palatal surgery 57

58. Sleep Well Flow Process
Physician Referral to Sleep Disorders Center
Sleep Physician Assessment
High Likelihood OSA Low Likelihood OSA
Embletta In-Home Monitoring Sleep Lab PSG Testing
Positive Negative
Auto CPAP Trial
Positive CPAP Responsive CPAP Unresponsive
Clinic Follow-up 58

59. Data available on 317 patients – one month f/u.
Outcomes
Data available on 317 patients – one month f/u.
- Successful:
RDI>5 + autoCPAP trial + compliance > 4 hours after 4 weeks 218 (69%)
- Unsuccessful: (18%)
- Declined/Refused/No Show (13%) 59

60. In a subset of patients with OSA, in-home testing is feasible
Summary
In a subset of patients with OSA, in-home testing is feasible
Up to 38% may qualify for home testing
Preliminary data shows that of those who qualify 69% can be diagnosed and treated at home
Patients prefer home testing to PSG. 60

61. Univ. of Saskatchewan
Thank you 61