Screening for OSA among DOT Examinees: Challenges and Advancement Chunbai Zhang, MD, MPH Medical Director Employee Occupational Health Service (EOHS) Silverman Institute of Healthcare Quality and Safety Beth Israel Deaconess Medical Center, Boston, MA Instructor of Medicine, Harvard Medical School PLEASE STANDY BY WEBINAR WILL BEGIN AT 12:00 PM PST FOR AUDIO: CALL 866-740-1260 / ACCESS CODE: 764-4915#
Conflict of Interest Disclosures: I have no financial relationships with commercial entities producing, marketing, re-selling, or distributing health care goods or services consumed by, or used on, patients relevant to the content I am planning, developing, presenting, or evaluating.
Content Attestation I, Chunbai Zhang, hereby declare that the content for this activity, including any presentation of therapeutic options, is well balanced, unbiased, and to the extent possible, evidence-based.
Outline 1. Brief background of OSA 2. Epidemiology of OSA among CMV Operators 3. Diagnostic Approaches among CMV Operators 4. Screening/Diagnostic Challenges 5. Case Discussion 6. Future Outlook
Obstructive Sleep Apnea
Who is at Risk for OSA?
OSA prevalence in U.S. is 2-10% OSA prevalence among commercial drivers : 17-28%
Prevalence of OSA among DOT examinees
Consequences (clues) of OSA
OSA Increases the Risk of Crash by 2-11 Fold
Case #1! 52 y.o. obese man presented to your office for biannual DOT exam. He reports of normal health. He denies significant medical history. He has been a driver for a local trucking company for 20 years.! You assess his sleepiness by a questionnaire Epworth Sleepiness Scale (ESS)
JTF Guideline 2008 for OSA Adapted from :Screening Recommendations for Commercial Drivers With Possible or Probable Sleep Apnea from Hartenbaum et al. J Occup Environ Med. 2006;48(9 Suppl):S4-S37.
ESS background:! Australia added the Epworth Sleepiness Scale (ESS) to its CDL health questionnaire.! At an occupational clinic setting, drivers behave differently from those found in sleep clinic (Durand JOEM 2009 and Parks JOEM 2009)! Low Epworth Score (avg: < 3 out of 24)! Low self-reported symptoms! doctor shopping
Epworth Sleepiness Scale (ESS)
Epworth SS = 0!!!
OSA Screening or Case - finding Methodology Subjective Questionnaires Objective Measurements Method I + - - Method II + + - Method III + + + Test Name Methodology Type False Negative Rate Ease of Use Test accuracy by DOR Applicability for Universal Screening (US) or Case Finding (CF) Both BQ I 0.081-0.382 1 Poorexcellent CHSQ I Utilizes BQ, no separate evaluation ESS II 0.714 1 poor Both STOP_BANG II 0-0.164 2 Averageexcellent Case Finding SA-SDQ III 0.149-0.25 1 Averagegood Case Finding MAP III 0.59-0.281 3 Poor-good Both Kushida III 0-0.062 3 Excellent Case Finding Index Predictive Modeling Ease-of-use scale, with 0 defining easy and 3 meaning complex methodology: 1 point each for four or more test elements or variables, log scale, and need for additional techniques measurements or investigations. Tests applicable for universal screening were previously validated in a general population while those applicable for case finding have been validated only in sleep clinics or populations with a high prevalence of OSA. DOR = diagnostic odds ratio BQ = Berlin Questionnaire, CHSQ = Cleveland Sleep Habits Questionnaire, ESS = Epworth Sleepiness Scale, STOP-BANG = Snoring, Tiredness during daytime, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, Gender, SA-SDB = Sleep Apnea scale of the Sleep Disorders Questionnaire, MAP = Multivariate Apnea Risk Index
Physical Exam: NAD, BMI 36, neck size 18 inch, tonsils size 0 x2 Mallampatti II. VS: BP mildly elevated. Otherwise normal exam What do you do next? Give him a normal 2 year DOT card? Give him a 6 month DOT card? Further testing? Call a sleep specialist?
Mallampatti Scale
Which tests shall you choose next? Home study or In-Lab sleep study?
In-lab polysomnogram (PSG)
MBTA Newton, MA (2008): NTSB Recommendations on OSA To all U.S. Rail Transit agencies: Medical exams should elicit prior diagnoses of obstructive sleep apnea or other sleep disorders and presence of risk factors. Identify operators at high risk for OSA or other sleep disorders and require that such operators be evaluated and treated. NTSB 2009
SCOPER Categorization System for Sleep Studies
PM Devices by SCOPER Categorization
Home Sleep Study (Portable Monitor)
Sleep Study Choices/Chain of Custody technology --- a moving target!
Advantages and Disadvantages of PMs vs. PSG
Sensitivity and specificity of various portable monitors to diagnose OSA
Potential Applicability of PM Studies among 100 High-risk CMV Operators
Adding a Z-Axis (Time) to the graph: It gets even more complicated!
The Watkins Study (2009)
Watkins Study (cont.)
Answer: it depends. on the pre-test probability (BMI, neck size, symptoms etc.)! High Pre-Test Probability! PM would suffice! Low/Moderate Pre-Test Probability! PSG considered!? Other sleep disorders! PSG considered! Occupational Setting! Chain of Custody if using PM
Case #2! The DOT examinee returns with a diagnosis of OSA! The DOT examinee reports of using CPAP now! You look at the sleep report:! AHI is 39! CPAP titration showed a pressure of 9 cm water was recommended by the sleep specialist! What do you do next?! 1. give him a one year DOT card! 2. check his CPAP compliance then decide! 3. ask for a CPAP titration study report! 4. he is disqualified because he has severe OSA.
Case #2 Definition of CPAP Compliance Medicare Criteria for Compliance: 1.! 4 hours/night AND 2. 70% of the Nights in 30 day period
Case 2 (answer)! Check his compliance:! Either a note from his sleep specialist, or! A compliance report print out from his CPAP machine: Does his CPAP compliance Meet the Medicare Criteria? What do you do now? -A year DOT card -Or 3 month DOT card
Case #3 The same DOT examinee returns 1 year later.!he tells you that despite his perfect CPAP compliance, he had residual daytime sleepiness.!his sleep specialist has placed him on Nuvigil (armodafinil) a week ago, which he claims is helpful.!what do you do next?! Disqualify him because CPAP did not help! Refer for CPAP re-titration study! Give him a one-year DOT card! Contact his sleep specialist for clearance
Modafinil (Provigil ) and Armodafinil (Nuvigil )! Mechanism is unclear (on dopamine receptors)! the viagra of the brain! Armodafinil is the R-enantiomer of Modafinil! FDA approved for adjuvant therapy for OSA! also used in Narcolepsy and Circadian rhythm disorder! Adverse Rxn: SJS, insomnia, nausea, dizziness
FMCSA guidelines on Modafinil! Need close monitoring by the prescriber! Usually titrated up to 150 mg or 250 mg! Recommend a 6-week monitor period! Documentation that the medication helps (?)! MSLT (multiple sleep latency test) may be needed! Rule out Narcolepsy (a rare but disqualifying condition)! Maximum 1 year DOT card if approved.
Key factoids in Obstructive Sleep Apnea (OSA) at Occupational Settings! OSA symptoms (daytime sleepiness, physical exam findings, sleep study)! DOT examinee s self-reported symptoms not reliable! Biometrics and Exams are important! Pre-test probability is important for choosing an appropriate study PM vs. PSG! Follow up and enforcement of sleepy drivers on the road! Keep in mind the goal: sleepiness, not OSA per se
Day-time Sleepiness independent of OSA During naps, sleep latency & wake time were significantly lower in obese subjects However, during nighttime testing, obese patients demonstrated significantly higher wake time Obesity may affect day-time sleepiness via a pathway independent of breathing-related sleeping disorder (BRSD)
Other Determinants of Sleepiness Age Obesity Diabetes Insulin Resistance/Visceral Adiposity Level of Physical Activity Depression/Emotional Stress *Vgnontzas AN, Sleep Med. 2008 October; 9(7) 712-4.
The Ultimate Questions for DOT exam: How do we know if a driver is sleepy enough to crash? On going research: PVT vs. Driving Simulation (JOEM, Zhang et. al. 2010)
Wrap Up:! OSA is a surrogate measure of sleepiness: Not everyone with OSA are sleepy; the sleepy ones may not have OSA! DOT examinees may not volunteer subjective reporting of sleepiness ( A Unique Challenge for Occ Med Providers)! Portable Monitors (PM): an evolving technology ( A Moving Target ). Chain of Custody is much needed! PSG vs. PM will depend on Pre-Test Probability! Post treatment compliance is important! Further data using PM in DOT examinees are needed! New tools are in development for sleepy driving
Q & A:! Questions? Or Comments?
Thank You
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