Disclosures Obstructive Sleep Apnea in the Underserved I have - - PowerPoint PPT Presentation

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Obstructive Sleep Apnea in the Underserved

February 23, 2017

George Su, MD Medical Director, Sleep Program Zuckerberg San Francisco General Hospital Associate Professor of Medicine, UCSF

Disclosures

I have nothing to disclose

Objectives

• 1. Pathogenesis and definitions
• 2. Prevalence/risk factors
• 3. Diagnosis
• 4. Management challenges

Obstructive sleep apnea (OSA)

• Estimated general prevalence 15% in U.S. (50-70 million cases)
• 50-78% rates reported in patients with obesity and diabetes
• Absenteeism, loss of productivity, 2x workplace accidents and MVAs
• 30% increased likelihood of death or heart attack, increased risk of

HTN, stroke, depression

• $3.4 billion in medical costs
• ~2x increase in healthcare utilization

Young, et al., 2009; Fredheim et al., 2011; Leong et al., 2013; Olson et al., 2006; Seicean et al., 2008; Ohayon, et al., 2009; Kapur, et al., 1999

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Loss of tone of pharyngeal dilators

Genioglossus (phasic)

Remmers, et al., 1984; Fogel et al., 2000

Tensor palatine (tonic) Genioglossal nerve activity Pressure (cm H2O) GG EMG (% of max)

Schwab, 1996

Cortical arousal

• Aiflow can increase without a

cortical arousal

• Arousal threshold lower with

OSA

Younes et al., 2004

OSA definition

• Decreased airflow due to repetitive complete or partial obstruction of

the upper airway

• Compensatory increase in respiratory effort
• Typically associated with cortical microarousals and decreased SaO2
• Sleep fragmentation and increased sympathetic neural activity

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Clinical presentation

• Excessive daytime sleepiness (EDS)
• Snoring, nocturnal choking or gasping
• Witnessed apneas
• Insomnia (maintenance insomnia, sleep initiation less affected)
• Nocturia, enuresis, frequent arousals, diaphoresis, impotence
• Fatigue, memory impairment, personality changes, morning nausea,

a.m. headaches, automatic behaviors, and depression

Scoring: “obstructive apnea”

Nasal Pressure Thermal Sensor Inductance Pleth Sum SaO2

AASM Scoring Manual Version 2.1, 2014

≥90% cessation

• f airflow for

≥ 10 seconds (with continued respiratory effort)

Scoring: “hypopnea”

Nasal Pressure Thermal Sensor Inductance Pleth Sum SaO2

≥ 30% decrease in (baseline) airflow for ≥ 10 seconds: ↓ ≥ 4% SaO2

• r, with↓ ≥ 3%

SaO2 or cortical arousal event (requires EEG)

AASM Scoring Manual Version 2.1, 2014

Scoring: respiratory event related arousal (RERA)

• Effort increase (flattening of the nasal pressure inspiratory curve)

followed by a cortical arousal

Nasal Pressure

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Apnea Hypopnea Index/Respiratory Disturbance Index

• AHI = (apneas + hypopneas)/sleep hour

Normal: < 5 Mild: 5 – 15 Moderate: 15 – 30 Severe: > 30

• RDI = (apneas + hypopneas + RERAs)/sleep hour

‒Can be large difference in AHI vs. RDI ‒e.g. with a young, thin patient who is less likely to desaturate by 4% with events

AASM Scoring Manual Version 2.1, 2014

“Standard” for diagnosis and therapy

Pre-test PSG PAP Rx Adherence

• Prevalence
• Incidence
• Presentation
• Awareness
• Undiagnosed

Pre-test

Diagnosis disparities

• 26% high-risk adults and ~80% with mod/severe OSA remain

undiagnosed

• Lower socioeconomic status associated with barriers to diagnosis
• Presentation disparities

Simon-Tuval et al., 2009; Young, et al., 2002; Young, et al., 2002

Risk disparities in OSA

Heritable Environmental Upper airway anatomy Regional fat distribution Craniofacial anatomy Other genetic factors Cultural: Attitude, support Symptom reporting Perception Socioeconomic status Diet/physical activity Education/awareness Access Co-morbidity Race/ Ethnicity/ Gender

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Familial and genetic predisposition

• First degree relatives at increased risk
• Risk increases with number of affected family members
• Susceptibility foci identified for OSA with locations for the linkage

patterns differing between Caucasians and African Americans

Strohl et al., 1978; Redline, 2000; Palmer, et al., 2004; Buxbaum, et al., 2002

Obesity

• Increased prevalence with increase in any measure of obesity (BMI,

waist-hip ratio, neck girth)

• 10% increase in weight increases odds of developing or worsening of

OSA by 6-fold

• 1986-2000 prevalence of severe obesity (BMI ≥ 40 kg/m2) increased

4-fold, and BMI ≥ 50 kg/m2 increased 5-fold

• Populations with high rates of obesity and diabetes, such as urban

non-white populations, may suffer disproportionate risk

• Impact of BMI on OSA is less significant after age 60

Bixler et al., 2005; Bixler et al., 1998; Ip et al., 2001; Peppard, et al., 2000; Tishler, et al, 2003; Ip et al., 2004; Young, et al., 2002 Schwab, 1996

Pharyngeal wall Para-pharyngeal fat pad Pharyngeal wall Para-pharyngeal fat pad Pre-weight loss Post-weight loss

Prevalence of OSA by age

Young, et al., 2002

35 45 55 65 75 85 Age (years) Prevalence 0.30 0.25 0.20 0.15 0.10 0.05 0.00

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Craniofacial anatomy

Lam et al., 2005

• OSA a/w with higher

thryomental angle (TMA) and Mallampati scores

• Asians with higher

TMA, Mallampati, and smaller thyromental distance (TMD) (after controlling for BMI and neck circumference)

• “retrognathia”

TMD TMA

Disparities with women

• Clinic-based studies OR: 4.13 for male risk factor; but recent large

population-based studies show prevalence 1.5-3 times higher in men

• Gap narrows after menopause and with hormone replacement
• LESS likely to report: “classic” snoring and witnessed apneas
• MORE likely to report: daytime fatigue, morning headache, mood

disturbance, depression

• Fewer apneic events and shorter duration with less O2 desaturation
• Symptomatic at lower RDI

Ancoli-Israel et al., 1995; Redline et al., 1994; Collop, 2004; Duran et al., 2001; Bixler et al., 1998; Breugelmans et al., 2004; Ware et al., 2000; Bixler et al., 2001; Shahar et al., 2003; O’Connor et al, 2000; Young et al., 1996

Disparities with ethnicity

• African American (AA):

‒more common in young (< 25 y.o.) vs. Caucasian (OR 1.88) ‒> 65 y.o. severe OSA (AHI ≥ 30 events/hr) more common (OR 2.55) ‒Bed partners more likely to accept snoring

• Asian: weaker association elevated BMI and OSA (prevalence similar)

‒Craniofacial anatomy differences

• Hispanic: increased rates of obesity, diabetes, CV disease

‒Prevalence of OSA may be higher (questionnaire and indirect measurements)

Redline et al., 1997; Young et al, 2002; Ancoli-Israel et al., 1995; Friedman et al., 2006; Ip et al., 2001; Ip et al., 2004

Barriers to diagnosis

Pre-test PSG Rx Adherence

• Prevalence
• Incidence
• Presentation
• Awareness
• Undiagnosed
• Specialized lab
• Access (wait times)
• Costs
• Overnight test
• Inconvenience
• Safety, comfort

Simon-Tuval et al., 2009; Billings et al., 2011; Kim et al., 2009; Bakker et al., 2011; Young, et al., 2002

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Polysomnography: “in-lab sleep testing” Polysomnography

• EEG, EOG, EMG
• ECG
• Airflow monitors
• Chest/abdominal bands
• Pulse oximeter
• Left/right leg EMG

→ Wakefulness and stage of sleep → Cardiac rate/rhythm → Apnea/hypopnea → Respiratory effort → SaO2 → Leg movements

Polysomnography

• Gold standard
• Small margins, no-shows are significant financial burden for labs
• Repeal of ACA
• “Split-night” studies (combine a diagnostic PSG and therapeutic

positive pressure titration) may decrease need for multiple studies ‒However, decreased time for diagnosis/titration often leads to need for repeat testing

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Portable sleep testing: “home sleep testing” Portable sleep test--home sleep test (HST)

• Airflow
• SaO2/HR
• Chest/abdominal excursion
• No EEG
• Uses wear time, as opposed to sleep time
• No technician

Events Flow Pulse SaO2 Effort

Home sleep test (HST) Portable sleep testing as strategy for high-risk vulnerable population?

• Validated with increasing sensitivity and specificity (76.7% and 92.5%)
• Recent studies on clinical outcomes support the use of HST in patients

with high pretest probability

• Using “type 3” data (as with HSTs) non-inferior to PSG
• Implementation of a billing code (in 2008)
• PSG is the recommended follow-up for a negative HST (high pretest

probability)

• No standard for lower pretest probability and limited access to PSG
• Access benefit and cost-effectiveness still unclear (payer vs. provider)

Sunwoo et al., 2010; Oktay et al., 2011; Collop et al., 2007; Chai-Coetzer et al., 2017; Kim et al., 2015

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Other methods for diagnosis? None recommended…

• Subjective screening questionnaires:

‒ Epworth Sleepiness Scale (ESS): sensitivity 46% and specificity 60% ‒ Berlin Questionnaire (BQ): sensitivity 73% specificity 44% ‒ STOP-BANG: ≥ 3 items (validated in obese surgical patients),

sensitivity 90%, PPV 85%

• Clinical diagnosis alone
• Nocturnal oximetry
• Auto-titrating positive airway pressure (APAP)
• Peripheral arterial tone, actigraphy

Barriers to diagnosis and therapy

Pre-test Testing Rx Adherence

• Prevalence
• Incidence
• Presentation
• Awareness
• Undiagnosed
• Specialized lab
• Access (wait times)
• Costs
• Overnight test
• Inconvenience
• Safety, comfort
• Access
• Costs
• Intolerance
• Inconvenience
• Vendor support

Continuous positive airway pressure (CPAP)

OSA AHI EDS (subjective) EDS (objective) Sleep arch Neuro- cognitive/ mood QOL CV risk Mod- Severe

+ + ± ± ± ± ±

Mild

+ ±

• ±
• ±

NA Patients WITH daytime symptoms

Kushida, et al., 2012; Weaver, et al., 2012

CPAP recommended practice

• CPAP Indications (standards):

‒Treatment of mod-severe OSA, improve EDS

• CPAP Recommendations (options):

‒Treatment of mild OSA ‒Improving QOL

• Full night in-lab PSG recommended method of titration
• Labor-intense to support use and adherence
• Medicare reimbursement rate competitive bidding process

AASM Practice Parameter; Kushida, et al., 2006; Gay, et al., 2006; Epstein, et al., 2009

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Positive airway pressure masks Auto-titrating PAP (APAP) recommended practice

• Clear: Uncomplicated mod-severe OSA
• Unclear:

‒REM-related OSA ‒Positional ‒High pressures (>10 cm H2O) ‒CPAP-intolerant

• NOT recommended (AASM standard):

‒CHF, COPD and chronic lung disease, OHS, other hypoventilation syndromes ‒Diagnosis of OSA

AASM Practice Parameter

PAP therapies

• Optimum form of PAP delivery and interface remain unclear
• Best PAP device and mask is the one the patient will WEAR!
• Lower socioeconomic status have lower adherence rates

Chung et al., 2008; Sunwoo and Kun, 2010; Oktay et al., 2011; Collop et al., 2007; Gay et al., 2006; Simon-Tuval et al., 2009; Billings et al., 2011; Kim et al., 2009; Bakker et al., 2011; Young, et al., 2002

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Oral Appliances Oral appliances: mandibular advancement

• Side effects: excessive salivation, jaw stiffness, TMJ, tooth pain,

malocclusion, loosening of dental work, gag

• Predictors for favorable response: younger, lower BMI, smaller neck

circumference, positional, lower AHI, favorable cephalometrics

• Effective, but inferior to PAP therapies for AHI/RDI reduction
• As effective as PAP in decreasing EDS, ESS, improving QOL
• Failure rate of non-custom devices 69%
• AASM: mild-moderate, and severe o.k. if cannot tolerate PAP
• Medicare DME medical benefit

Vanderveken et al., 2008; Lettieri et al., 2011

Exercise and weight loss: “10-30” rule

Peppard et al., 2000

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Exercise and weight loss

• RDI is more sensitive to weight change in men (vs. women)
• Very low calorie diet (VLCD): 600-800 kcal/day for 12 weeks followed

by lifestyle modification visits (14 over a year) − Weight loss 10.7 kg vs. 2.4 kg with mean reduction AHI 4 vs. 0

• Short-term (12-16 wks) aerobic exercise and resistance training

− In mild-moderate OSA, AHI improved ~8 events/hr independent of any significant reductions in BMI − Epworth score and sleep efficiency also improved

Peppard et al., 2000; Tuomilehto et al., 2009; Iftikhar et al., 2014

Other non-PAP therapies…? MOC Question

Which statement regarding OSA in the underserved is correct?

• a. Higher risk for OSA in the underserved can be attributed to obesity

alone

• b. Portable “home” sleep testing is a highly sensitive and specific

diagnostic modality with proven cost benefits

• c. Access to polysomnography, the gold standard for diagnosis, is

severely limited by narrow operating margins for test providers

• d. Oral appliances are currently an accessible alternative to PAP

therapies in the underserved

OSA in the underserved

• OSA is a highly prevalent and morbid condition
• Diagnosis and treatment pathways are vulnerable for the underserved
• Patient, delivery system, testing and vendor operating margins, and

policy factors all contribute to underdiagnosis, underprescription, and poor adherence to treatments

• Technology advances (e.g. portable studies) may help bridge access

gap; however, need better alignments in health economics

• PAP therapies remain the gold standard, newer technologies may help

target poor adherence, and non-PAP therapies may play a larger role

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Thank you!

George Su, MD george.su@ucsf.edu