Dealing with Sleepiness in Transportation WorkersStefanos N. Kales MD, MPH, FACP, FACOEMFACP, FACOEM

MEDICAL DIRECTOR EMPLOYEE HEALTH & INDUSTRIAL MEDICINE

CAMBRIDGE HEALTH ALLIANCE

ASSOCIATE PROFESSOR, HARVARD MEDICAL SCHOOL

ASSOCIATE PROFESSOR and DIRECTOROCCUPATIONAL & ENVIRONMENTAL MEDICINE RESIDENCY,

HARVARD SCHOOL OF PUBLIC HEALTH

Funding

– Harvard School of Public Health, NIOSH Education and Research Center (ERC)

– American College of Occupational and Environmental Medicine (ACOEM)

– Federal Motor Carrier Safety Administration (FMCSA), U.S. Department of Transportation (DOT)

– Respironics, Inc.

– Consultant to Novartis

Bus Driver Rear-Ends Parked Bus

55-year-old male, 12 years school bus driver

Students: “Driver’s head resting on steering wheel” while students boarding

“Frequently dozed off at red lights and bus stops”

Fitness for DutyBMI 37 kg/m2

Neck circumference >17 in

Uncontrolled Hypertension (Stage 2)

Polysomnography – Apnea-hypopnea index (AHI)=73

– Nadir SpO2 =69%

– 28% sleep time SpO2 <90%

“My uncle never crashed, but he frequently had to stop his truck and nap….

MD who did his DOT exam never asked about OSA or to have a sleep study.

This went on for months until I finally convinced him to be tested…

Thank God, Uncle Joe retired.”

Uncle Joe’s Dump Truck Siestas

Why are Sleepy Drivers Important?

Roughly 8-14 million Commercial Drivers License (CDL) holders in US

Large proportion of motor vehicular crashes due to fatigue and/or sleep disorders.

Estimates range from 10% to 30%.

Why are Sleepy Drivers Important?

Large truck crashes:

50% lead to death or incapacitating injury

> 5,300 deaths & >104,000 injuries/year

from bus/truck crashes (DOT 2003-2007)

(about One tenth of numbers for Flu in US)

Factors Affecting Operators & Sleepy Crashes

• Sleep Deprivation• Poor Sleep Hygiene• Travel/shift work• Altitude• Alcohol/Drugs• Sleep medication

• Other Sleep disorders• Obstructive Sleep Apnea

Clinical Sleep Disorders

Dagan et al 2006

Israeli truck drivers with BMI >/=32

100% denied all symptoms of OSA/EDS

78% PSG-confirmed OSA & EDS by MSLT

Epworth SS = 0

Snow Plow Scott- CDL Form

Also had Severe OSA, Untreated

Snow Plow Scott- PCP Progress Note

Intervention: Unrestricted sleep, sleep restricted to 4 hours, and vodka to achieve BAC 0.05 g/dL.

Conclusion: OSA Patients more vulnerable than healthy persons to EtOH & sleep restriction on driving performance.

Ann Intern Med. 2009;151:447-455.

Results: OSA more steering deviations, slower braking, more crashes

Mexican Hat, Utah Jan 2008

Bus ran off the road killing 9 & injuring 43

NTSB: driver fatigue likely root cause

Sleep apnea “trouble” using CPAP

Altitude sickness & URI also likely interfered with his sleep

OSA Increases the

Risk of Crash by 2-11 Fold

BMI > 29: RR of OSA >10

BMI >/=32: Chance of OSA ~75%

1980: 15% of US adults Obese

2000: 30% Obese

2018: 43% Will Be Obese

OSA prevalence in U.S. is 2-10%

OSA prevalence in commercial drivers 17-28%

During naps, sleep latency & wake time were significantly

lower in obese

However, during nighttime testing, obese patients demonstrated significantly higher wake time

Arch Intern Med. 1998.

BIXLER, E.O. et al. 2005. Excessive daytime sleepiness in a general population sample: the role of sleep apnea, age, obesity, diabetes and depression.J. Clin. Endocrinol. Metab.

Stoohs et al.

Sleep 1994

US DOT Modal Administrations

* http://www.fra.dot.gov/downloads/safety/hazmatch2.pdf

FMCSA Guideline for OSA *

• Narcolepsy and sleep apnea account for about 70% of EDS. Persistent or chronic sleep disorders causing EDS can be a significant risk to the driver and the public. The examiner should consider general certification criteria at the initial and follow-up examinations:– Severity and frequency of EDS– Presence or absence of warning of attacks– Possibility of sleep during driving– Degree of symptomatic relief with treatment– Compliance with treatment.

* http://www.fmcsa.dot.gov/rules-regulations/topics/medical/faqs.aspx?FAQTypeSub=1010&FaqQ=#question2

FMCSA Guideline for OSA*•  ”Drivers should be disqualified until the

diagnosis of sleep apnea has been ruled out or has been treated successfully, [unless] a CMV driver agree to continue uninterrupted therapy such as CPAP and undergo objective testing as required.”

• “A driver with a diagnosis of (probable) sleep apnea or a driver who has Excessive Daytime Somnolence (EDS) should be temporarily disqualified until the condition is either ruled out by objective testing or successfully treated.” * http://www.fmcsa.dot.gov/rules-regulations/topics/medical/faqs.aspx?FAQTypeSub=1010&FaqQ=#question2

FMCSA Regulations: “no established …respiratory dysfunction likely to interfere with the ability to control

and drive a commercial motor vehicle safely.”

FAA Guidelines for OSA

* 2010 Guide for Aviation Medical Examiners: page 71

FAA Guidelines for OSA

• AME Assisted Special Issuance (AASI) is a process that provides Examiners the ability to re-issue an airman medical certificate under the provisions of an Authorization for Special Issuance of a Medical Certificate (Authorization) to an applicant who has a medical condition that is disqualifying under Title 14 of the Code of Federal Regulations (14 CFR) part 67.

An FAA physician provides the initial certification decision and grants the Authorization in accordance with Title 14 of the Code of Federal Regulations. The Authorization letter is accompanied by attachments that specify the information that treating physician(s) must provide for the re-issuance determination.

FAA Guidelines for OSA• Examiners may re-issue an airman medical certificate

under the provisions of an Authorization, if:1. An authorization granted by the FAA;2. a current report (performed within last 90 days) from the treating physician that references the present treatment, whether this has eliminated any symptoms and with specific comments regarding daytime sleepiness. 3. Maintenance of Wakefulness Test (MWT) will be required if questions on non-compliance or no response.

• The Examiner must defer to the Aerospace Medical Certification Division (AMCD) or Regional Flight Surgeons if:1. There is any question concerning the adequacy of therapy;2. The applicant appears to be non-compliant with therapy;3. The MWT demonstrates sleep deficiency; or4. The applicant has developed some associated illness, such as right-sided heart failure.

Deficiency in FAA Guidelines

• Does not screen for presence of OSA

• Does not ask questions concerning a history of OSA or symptoms (i.e. EDS)

• No guidance to AMEs for risk factors for sleep disorders that maybe related to OSA

Federal Railroad Administration (FRA) on OSA

• FRA requirement exam includes only tri-annual vision and hearing testing

• Additional medical exam is required when a) post-offer b) promotion to a safety-critical position, or c) when fitness-for-duty is questioned

• Most railroads have no written standards• Only 3 entities (1 Class One Railroad Norfolk

Southern + 2 commuter railroads: NJ Transit, Metro-North) require periodic medical exams *

http://www.fra.dot.gov/downloads/safety/hazmatch4.pdfhttp://www.fra.dot.gov/Downloads/safety/hazmatexsum.pdf

USCG non-military on OSA

* http://www.fra.dot.gov/downloads/safety/hazmatch2.pdf

Joint Task Force OSA Guidelines

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.

Drivers meeting one or more of the six criteria are considered to have OSA or probable OSA.

Historical Findings 1. Snoring, excessive daytime sleepiness, witnessed apneas2. MVA likely related to sleep disturbance (run off road, at-fault, rear-end collision)3. Previous OSA diagnosis

Epworth Sleepiness Scale 4. ESS score > 10

Physical Examination Findings

5. Sleeping in examination or waiting room6. Two or more of the followinga. BMI >/= 35 kg/m2

b. NC > 17 inches in men, 16 inches in womenc. Hypertension (new, uncontrolled, or unable to control with < 2 medications)

“New study supports mandatory screenings,

prohibition of ‘doctor shopping’.”

n = 456

n = 378n = 78

n = 53

Referred for PSG

Screened (+)* Screened (-)

n = 13 n = 7

n = 20

Total number of subjects

with confirmed OSA‡

n = 33

Lost to follow-up†

Total number of drivers examined

Underwent PSG and provided PSG results

Positive for OSA by PSG

n = 25

Not Referred for PSG

Positive for OSA by Self-Report

Admitted to past OSA diagnosis

OSA Screening Flow Chart

Parks et al. JOEM 2009

SubjectAge

(years)Gender

BMI(kg/m2)

NC(inches)

ESS Symptoms AHIMinimum O2

Saturation Diagnosis*

CPAP Compliance†

1 67 Male 35.29 16.5 11 Snoring 115 84 PSG Not Provided

2 47 Male 46.16 18.5 1 Snoring 104 78 PSG Not Provided

3 46 Male 40.60 18.5 4 Denied 75 86 PSG Not Provided

4 52 Male 35.89 17.0 5 Denied 72 86 PSG 3.6 hours/day

5 32 Male 35.77 18.0 1 Snoring 70 53 PSG Not Provided

6 42 Male 38.69 18.0 2 Snoring 70 63 PSG Not Provided

7 20 Male 35.12 19.0 4 Snoring 44 86 PSG 0.13 hours/day

8 35 Male 43.12 18.75 1 Denied 36 74 PSG Not Provided

9 45 Male 36.44 17.5 3 Snoring 34 83 PSG 6 hours/day

10 39 Male 37.46 18.0 3 Denied 34 86 PSG Refused CPAP

11 41 Male 33.67 16.5 2 Snoring 30 82 PSG Not Provided

12 41 Male 41.65 18.0 10 Snoring 15‡ 82‡ PSG 1.27 hours/day

13 45 Female 49.19 18.25 1 Denied 14 86 PSG Refused CPAP

14 56 Male 33.94 18.50 5 Denied 11 68 PSGDid not tolerate

CPAP

15 27 Male 35.73 18.5 8Snoring, pauses

in breathing8 81 PSG Not Provided

16 53 Male 35.98 18.5 0Snoring, daytime

sleepiness-- -- Self-report

Not Provided

17 27 Male 37.10 17.5 4 Denied -- -- Self-report Not Provided

18 42 Male 41.93 19.0 0 Denied -- -- Self-report Not Provided

19 58 Male 30.56 17.0 1 Denied -- -- Self-report Not Provided

20 50 Male 26.14 -- 1 Denied -- -- Self-report Not Provided

Mean 43.25 -- 37.52 17.97 3.35 -- 48.91 78.53 -- --

Median 43.50 -- 36.21 18.00 2.50 -- 36.40 82.00 -- --

Characteristic Screened (+) for OSA* and Diagnosis

Confirmed†

(n = 20)

Screened (+) for OSA* but Diagnosis Unconfirmed p-value

Referred for PSG but Lost to Follow-Up‡

(n = 33)

Not Referred for PSG(n = 25)

Men –n (%)

18 (94.7) 33 (100) 24 (96.0) 0.461

Independent Drivers – n (%)

2 (10.5) 3 (9.1) 7 (28.0) 0.105

Age range –years

20-67 25-66 27-61 --

Mean age –years (+/- SD)

43.25 (11.43) 43.12 (11.26) 42.80 (8.57) 0.989

Mean BMI –kg/m2 (+/- SD)

37.52 (5.22) 36.92 (3.86) 32.14 (3.69) <0.001

Mean NC –inches (+/- SD)

17.97 (0.78)(n = 19)

17.9 (1.01)(n = 32)

17.27 (0.98)(n = 23)

0.026

Mean SBP –mm Hg (+/- SD)

128.40 (15.24) 126.73 (10.95) 129.68 (13.05) 0.682

Mean DBP –mm Hg (+/- SD)

79.30 (9.14) 81.39 (6.07) 84.56 (6.89) 0.052

Mean ESS –(+/- SD)

3.35 (3.17) 3.35 (3.02)(n = 31)

4.04 (3.36)(n = 23)

0.688

Comparison of subjects with + OSA screen: confirmed diagnosis vs. no confirmation of diagnosis by polysomnography.

Results - Summary

• Estimated PPV of JTF Criteria = 20/20 = 100%

• Subjective Criteria ~ little value

• Estimated prevalence of OSA in the study population:

– 12% (95% CI, 8.68-14.56%) – JTF criteria (BMI ≥ 35 kg/m2)

– 18% (95% CI, 14.86-21.98%) - BMI ≥ 32 kg/m2

• Loss to follow-up rate 33 of 53 (62%);

• 95% diagnosed drivers non-compliant with CPAP

Talmage et al 2008

198 (13%) of 1443 CDME’s OSA screen +

Subjective / Symptom Criteria low utility

134 underwent PSG, 95% had OSA

64 lost to f/u (32%)

N=552 MD’s performing CDME’s

OSA Screening of Drivers

92% “important or very important”

6% “moderately important”

2% “slightly important or not important”

Survey of ACOEM Members

Only 42% using the consensus guidelines or other formal protocol.

Reasons for not applying guidelines: not aware (36%)too complicated (12%)potential to lose clients (10%)driver inconvenience (10%)

Most physicians would consider applying consensus guidelines going forward

39% would do so only based on additional data

22% only if they became the “standard of practice”

MEP recommended: BMI >/=33 trigger referral for PSG

MRB: BMI cut point >30 trigger referral for PSG

MRB Motion carried four to one.

Jan 2008

MBTA Crash Newton May 2008

Operator of striking train at high risk for undiagnosed OSA

Operator failed to respond to signals and several opportunities to slow or stop train

Likely because of a

micro-sleep episode

NTSB 2009

NTSB: Sleep apnea, fatigue fromschedules contributed to tired “go!” pilots

Captain and first officer overflew destination in Hawaii, inadvertently fell asleep while on autopilot

53-year-old pilot was diagnosed (after the incident)

 with severe obstructive sleep apnea

MBTA Newton May 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

All drivers screened by questionnaire and driver fitness medical examination (BMI & BP)

Drivers meeting Screening Criteria- Sleep study via network of Clinics across US

If sleep study positive, immediate (same morning) education and “Driver-friendly” treatment

CPAP compliance tracked by nurses/safety department

Results among Drivers with OSA who were treated:

Saving of $578/driver/month in medical costs

30% decrease in fatigue-related crashes

Higher retention of drivers with company

Dunlap v. Logan Trucking Company

Truck driver struck another vehicle head-on, killing the other driver.

Evidence showed the truck driver falling asleep at the wheel

“Sudden Medical Emergency” Defense.

Dunlap v. Logan Trucking Company

Court concluded: he knew or should have known that falling asleep at the wheel was a potential risk given his health conditions.

Both truck driver and employer were found partially liable for the accident.

Conclusions

• OSA prevalence high across studies.

• Drivers under-report sleep disorders

• Low compliance with PSGs referrals and CPAPtreatment suggest Doctor-Shopping

Most OSA cases unreported, undiagnosed, or untreated & contribute to significant public safety risks

ConclusionsScreening Criteria must be OBJECTIVE and SIMPLE

(i.e. single BMI cutoff)

Authorities should mandate OSA screening& Prohibit Doctor-shopping

Cost, access, wait times, and insurance status are significant barriers to many commercial drivers

Employer-based solutions can be very effective

Education of MD’s, Drivers, Trucking Companies & Insurers Needed

Final Case- School Bus Driver

Final Case- School Bus Driver

BMI 32 kg/m2

Neck circumference 17.5 in

Uncontrolled Hypertension (Stage1 & 2)

Denies All Symptoms; ESS = 0

Polysomnography – AHI=11; Supine AHI and REM AHI both 24

– Nadir SpO2 =93%

– Loud Snoring– Sleep Efficiency 60%

Kales et al 2010

Thank You!

Discussion / Questions