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Dealing with Sleepiness in Transportation Workers. Stefanos N. Kales MD, MPH, FACP, FACOEM MEDICAL DIRECTOR EMPLOYEE HEALTH & INDUSTRIAL MEDICINE CAMBRIDGE HEALTH ALLIANCE ASSOCIATE PROFESSOR, HARVARD MEDICAL SCHOOL ASSOCIATE PROFESSOR and DIRECTOR
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Dealing with Sleepiness in Transportation Workers Stefanos N. KalesMD, MPH, FACP, FACOEM MEDICAL DIRECTOR EMPLOYEE HEALTH & INDUSTRIAL MEDICINE CAMBRIDGE HEALTH ALLIANCE ASSOCIATE PROFESSOR, HARVARD MEDICAL SCHOOL ASSOCIATE PROFESSOR and DIRECTOR OCCUPATIONAL & 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 Duty BMI 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%
Uncle Joe’s Dump Truck Siestas “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.”
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
Snow Plow Scott- CDL Form Epworth SS = 0
Snow Plow Scott- PCP Progress Note Also had Severe OSA, Untreated
Intervention: Unrestricted sleep, sleep restricted to 4 hours, and vodka to achieve BAC 0.05 g/dL. Results: OSA more steering deviations, slower braking, more crashes Conclusion: OSA Patients more vulnerable than healthy persons to EtOH & sleep restriction on driving performance. Ann Intern Med. 2009;151:447-455.
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
1980: 15% of US adults Obese 2000: 30% Obese 2018: 43% Will Be Obese BMI > 29: RR of OSA >10 BMI >/=32: Chance of OSA ~75%
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
FMCSAGuideline 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
FMCSAGuideline 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; or 4. 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 *http://www.fra.dot.gov/downloads/safety/hazmatch4.pdf *http://www.fra.dot.gov/Downloads/safety/hazmatexsum.pdf 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 *
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.
“New study supports mandatory screenings, prohibition of ‘doctor shopping’.”
n = 456 Total number of drivers examined Screened (+)* Screened (-) n = 78 n = 378 Not Referred for PSG Referred for PSG n = 53 n = 25 Underwent PSG and provided PSG results Admitted to past OSA diagnosis n = 13 n = 7 n = 33 Lost to follow-up† Positive for OSA by Self-Report Positive for OSA by PSG n = 20 Total number of subjects with confirmed OSA‡ Parks et al. JOEM 2009 OSA Screening Flow Chart
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”
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” Survey of ACOEM Members
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 CPAP treatment suggest Doctor-Shopping Most OSA cases unreported, undiagnosed, or untreated & contribute to significant public safety risks