Sleep Apnea- A Smoke Screen for Many Truck Driver Fatigue Issues
Written by Allen Smith
by Allen Smith
Driver Fatigue and Sleep Apnea
Driver Fatigue is no stranger to the trucking industry. The FMCSA has performed studies in the past in order to better understand what causes driver fatigue and how to reduce it by correcting the major contributing sources.
Back in 1996, a 7 year study, The Commercial Motor Vehicle Driver Fatigue and Alertness Study (DFAS), was published by the FMCSA evaluating driver fatigue. At the time, Hours of Service was under review and many contributors to driver fatigue were considered. The cost of this study was 4.45 million dollars. This is the Introductions written by the FMSCA concerning this study.
“The Driver Fatigue and Alertness Study (DFAS) was the largest and most comprehensive over-the-road study ever conducted on driver fatigue and alertness in North America. It provides extensive information on the alertness, driving performance, and physiological and subjective states of commercial motor vehicle (CMV) drivers as they perform real-life, revenue-generating trips. This Executive Summary overviews the objectives, methods, principal findings, and safety implications of this landmark 7-year study.”
During this comprehensive study this is what was concluded in regards to the concerns of Sleep Apnea:
“Although this study was not designed to determine a population prevalence, analysis of subject sleep revealed that two of the 80 drivers (2.5%) had clinically-diagnosable apnea, a sleep disorder characterized by breathing cessations. The driving performance of these two individuals was not statistically different from that of other comparable drivers in the study.”
The Study concludes with:
ASSESSMENT OF RESULTS FOR FATIGUE MANAGEMENT:
“There is no quick fix and no single solution to the fatigue problem. Sleep is the principal countermeasure to fatigue…. Partnerships among government, industry, drivers, safety groups, the scientific community, and shippers are needed for effective solutions to the commercial motor vehicle driver fatigue problem.”
In an article by Misty Bell of eTrucker , Mary Gunnels, director of the Federal Motor Carrier Safety Administration Medical Programs made the statement “We know that fatigue is a problem,” she said, “and we know that sleep apnea is a major contributor to fatigue.”
Do we really know that sleep apnea is the major contributor? Where is the data?
In that same article, Martin R. Walker, chief, FMCSA Research Division, pointed to the prevalence of sleep apnea in commercial truck drivers, noting that a study published in 2002 found that almost a third of CMV drivers have mild to severe obstructive sleep apnea. This study, along with a later study, found that older age and higher body mass index are two factors commonly linked with sleep apnea. 30% of drivers have mild to severe sleep apnea? How could that be? The 7 year study performed by the FMCSA didn’t come close to those figures?
I decided to look at the research, and this is what I came up with:
It appears that these figures and statements made during the Sleep Apnea & Trucking Conference of May 12, 2010 were possibly based on this study. At least this is the only study I could find actual data on.
The study was conducted by the University of Pennsylvania Sleep Apnea Study. The research was conducted during 1996 to1998. Sleep apnea is a condition in which a narrowing or closure of the upper airway during sleep causes repeated sleep disturbances, and possible complete awakenings, leading to poor sleep quality and excessive daytime sleepiness. This study was completed to assess the risks of commercial motor vehicle (CMV) crashes due to the presence of sleep apnea among truck drivers.
Basically, this study involved 1391 drivers. The drivers were asked a series of questions, including their height and weight, sleep patterns, medical history, snoring, etc. This was used as a screening process to determine which drivers were most likely to have sleep apnea. Out of the 1391 drivers, 406 were selected as a result of their questionnaire, to proceed with the overnight laboratory study in order to determine how many of them were accurately predicted to have sleep apnea.
The results were as follows:
64% or 260 of the 406 flagged for most likely to have sleep apnea had no sleep apnea. 21.2% or 86 of the 406 flagged for most likely to have sleep apnea had mild sleep apnea. 7.9% or32of the 406 flagged for most likely to have sleep apnea had moderated sleep apnea. 6.9% or 28 of the 406 flagged for most likely to have sleep apnea had severe sleep apnea.
Now, the above percentages and figures are for the 406 flagged drivers. When you perform the calculations based on the group study of ALL 1391 Drivers, here are the results ( the calculation required to accurately represent and determine % of ALL drivers):
2.0% or 28 of total 1391 drivers had severe sleep apnea ( matches the 1st study by FMCSA- DFAS) 2.3% or 32 of total 1391 drivers had moderate sleep apnea 6.2% or 86 of total 1391 drivers had mild sleep apnea.
This would mean that only 4.3% of drivers have moderate to severe sleep apnea. If you include mild sleep apnea, the % jumps to 10.5%
The following statement in the report however is the most revealing of all:
“The results of the study showed that the prevalence rates of sleep apnea among commercial truckdrivers are similar to sleep apnea rates found in other general populations.” The study also revealed that the prevalence of sleep apnea depends on the relationship between two major factors – age and degree of obesity as measured by body mass index (BMI) – with the prevalence of sleep apnea increasing with increasing age and BMI. Another meaningful study finding showed that the prevalence of sleep apnea depends on the average duration of sleep over consecutive nights at home. Short sleep duration, six hours or less per night, results in an increase in the prevalence of sleep apnea.”
Here’s that last statement again which has not been mentioned by the authorities and experts as a major source of sleep apnea,” Short sleep duration, six hours or less per night, results in an increase in the prevalence of sleep apnea.”
When you consider that the average OTR truck driver gets 5.2 hours sleep/night, then you have to wonder if it is the trucking industry lifestyle, behavior, and rules which are major causes for driver fatigue and also for creating/inducing “driver sleep apnea.”
The original hypothesis tested was the following: “A driver diagnosed with sleep apnea is more likely to be involved in a motor vehicle crash than a driver with no history or symptoms of sleep apnea, after controlling for differences in the other predictor variables included in the model.“
Finally, the study concluded to say, “No association was found between sleep apnea presence or severity and multiple crashes. This suggests that the commercial drivers in this study who were diagnosed with sleep apnea were not at increased risk for having more than one crash over the 14 year period prior to and following diagnosis…. Furthermore, there was no evidence from the data used in this study to suggest that crash risk is impacted before and after drivers are diagnosed with sleep apnea.”
There are many reasons for Driver Fatigue, and despite what many would like you to believe, lack of available sleep is the major cause. Sleep Apnea appears to represent a much smaller percentage than what is being stated. The data strongly suggests this.
Although sleep apnea is a real condition, it represents a much smaller percent of the driver population than the FMCSA and the ATA are suggesting. To screen a driver by height and weight (BMI), and neck size ( 17 or greater) is not only discriminatory, but is ludicrous. To force drivers to pay for the testing based on such information is simply wrong and unjust. A serious look at other reasons for driver fatigue should be investigated.
On the other side of that coin, if you do believe you may have sleep apnea, then you should by all means be tested and start the treatment.
The FMCSA needs to create laws, ensuring that drivers are not sleep deprived rather that associate driver fatigue on the hype of sleep apnea. It appears this is just a way to take the attention off of the real and valid reasons that drivers are fatigued, thus relieving the responsibility from carriers, shippers, and receivers who are all a part of depriving drivers from the rest they need. It’s also a way to deviate attention from the present HOS rules which need to be modified in order to aid in better and more rest for drivers.
Creating a sleep apnea testing program will be a BIG money maker for many as well as one more excuse to eliminate “undesirable” drivers from the industry.
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