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| Journal of the New Zealand Medical Association,
27-August-2010, Vol 123 No 1321
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In New Zealand, motor vehicle accidents (MVAs) account for
over 30% of all deaths from external causes.1
Alcohol, speed, and not wearing seat belts are commonly identified as causal
factors,1 however driver sleepiness and fatigue
are estimated to contribute to 20% of all injury
crashes.2
Obstructive sleep apnoea syndrome (OSAS) is a medical
condition that is associated with elevated sleepiness and a heightened risk of
MVAs.3–5 This condition is characterised
by repetitive episodes of complete or partial upper airway obstruction that
occur during sleep, and are usually terminated by brief
arousals.6 Disease severity is defined by the
number of apnoea (complete obstruction) and hypopnoea (partial obstruction)
events per hour of sleep, as measured by the apnoea-hypopnoea index
(AHI).6-8
The most common treatment for OSAS is nasal continuous
positive airway pressure (CPAP), which splints the airway open during sleep and
significantly improves daytime sleepiness.9,10
The profile of risk factors for OSAS suggests that prevalence may be high among
professional drivers. These include being male, middle-older age, and having an
elevated BMI, which may be exacerbated by the sedentary lifestyle of
professional drivers.
Our recent study (n=243) estimated a high proportion (15%)
of moderate to high risk of OSA among a sample of New Zealand-based taxi
drivers.11 In that study, our prediction
equation was used to estimate the probability of having at least 15 respiratory
disturbance events (apnoeas) per hour of sleep, using the respiratory
disturbance index (RDI≥15). The equation included the following variables:
being male, increasing age, increasing neck size, excessive daytime sleepiness
(ESS>10), snoring ‘always’, and reported observed apnoeas. These
variables have been shown to be consistent predictors of
OSA,12 and thus it is considered to provide
reliable estimates of a priori probability of OSA with 71–80%
sensitivity and 81–86% specificity. This predictive model is in the
process of being prospectively validated.
An Australian study of commercial vehicle drivers (n=2342)
found 16% had OSAS.13 A recent study found an
unexpectedly high prevalence (77.7%) of OSA (at least five respiratory
disturbances per hour of sleep, RD≥5) among 153 Israeli professional
drivers,14 of whom 47.1% were classified as
sleepy, and 19% had severe sleepiness (classified as an average sleep latency on
the multiple sleep latency test ≤ 5minutes). Another study of 216 Hong
Kong bus drivers found over 9% had OSAS, as defined by having an RDI≥5 and
having excessive daytime sleepiness (Epworth Sleepiness Score≥10).
There is minimal information available about the prevalence
of sleep disorders among professional taxi drivers, who are at elevated risk for
MVAs because of the extended time they spend driving, compared to
non-professional drivers. In New Zealand, the taxi industry has recently
undergone significant deregulation, which some industry participants believe has
resulted in a progressive decline in drivers’ working conditions and a
surplus of taxi cabs and drivers.15 Some
drivers maintain that this has forced them into working longer hours in order to
earn a living.16
The increased MVA risk among untreated OSAS sufferers has
drawn the attention of regulatory authorities in a number of countries,
including New Zealand and Australia.17–19
The debate centres on whether OSAS sufferers should be allowed to hold certain
categories of driving license, and on the conditions under which treated OSAS
sufferers should be allowed to continue to drive. A major difficulty is
predicting who is at elevated risk for MVAs, because the severity of sleep
disordered breathing is not reliably correlated with measures of daytime
sleepiness.
Risk assessment for the individual OSAS patient currently
remains a clinical decision based on a combination of objective and subjective
information.20 Clinicians may (but are not
obliged to) advise the chief medical advisor outlining a drivers’ medical
and driving circumstances, and make appropriate recommendations (e.g.
temporarily suspend a drivers’ license pending adequate treatment of
OSAS).18
In New Zealand, access to specialist services for the
diagnosis and treatment of OSAS is through referral from general practitioners
(GPs), who are also typically responsible for follow-up evaluation of the
adequacy of treatment, should this be imposed as a condition for driver
licensing.
The aim of this research was to explore the attitudes of
professional taxi drivers around OSAS symptoms. In particular, the study sought
to better understand how drivers’ attitudes influence their behaviour with
regard to managing their health and safety as a professional driver.
MethodsTwo local taxi companies distributed study packages to
their drivers, which included a two-page questionnaire and a consent form for
participation in a focus group. A total of 125 consent forms were returned. For
each participant, questionnaire responses were used to derive a pre-test risk of
OSA, defined as having an RDI≥15, based on a multivariate predictive
model.11 Recruitment continued until there were
sufficient numbers in each focus group.
The groups were conducted at the Research School of
Public Health, Massey University (New Zealand), in an environment that offered a
neutral context for drivers to interact freely and with anonymity from their
company management. The focus groups were co-facilitated by one of the named
authors (RF) and a qualified medical physician. Each group lasted two hours.
Nominal group technique was employed to minimise influence and tangential
discussion.21
In line with this technique, participants were asked to
write their responses to a set of semi-structured questions (“Think of
a time when you were working [as a taxi driver], and you felt really tired, not
refreshed, and sleepy on the job, now consider these following questions.”
How did you feel working in this situation? Were you worried about how you could
perform as a taxi driver? If you were worried, what did you do about it?).
Each participant’s responses were transcribed
openly, and common ideas and different responses were identified, and used to
prioritise topics and initiate group discussion. The focus group methodology is
described in detail elsewhere.16 Table 1
describes the characteristics of each focus group. The “Other
Ethnicity” group was self-identified, and included drivers from Asia,
Fiji-Indian, and northern and eastern European countries.
Table 1. Focus group
characteristics
ResultsOne major theme identified from the analysis of the focus
group transcripts,16 and which is the focus of
the analyses presented here, was characterised as “driver avoidance of
health issues and dissatisfaction with doctors”. Within this
major theme, three sub-themes were identified, namely: ignorance, avoidance, and
personal fear.
IgnoranceIgnorance was defined as a lack of awareness about
the underlying causes of sleepiness, and the potential risks of sleepy driving,
and a lack of knowledge about the availability of treatment services for OSAS.
It included both driver ignorance and ignorance among medical professionals. The
following excerpts typify driver ignorance.
Driver 21
added: “I think most people [are] not aware that this is a
problem. It’s just one of the things that happen! ...I think it’s
just a lazy type of job you just sitting down—ya got nothing else to do
[laughs.]”
Driver 22:
“...my problem [i.e. OSAS] was identified with snoring. My wife
complained to my doctor and she was the one that started this whole
investigation off.”
Drivers were generally unaware that a symptom such as
sleepiness could be an indicator of an underlying medical problem. Some blamed
the sedentary nature of the job, which was perceived as inducing daytime
sleepiness. This demonstrates ignorance of the physiological basis of
sleepiness. As expected, drivers who had OSAS symptoms during sleep were unaware
of them, until family members highlighted these issues.
Some drivers reported good relationships with their GPs and
attended regular check-ups. However, their involvement in the focus groups had
clearly heightened their awareness about OSAS symptoms and the dangers of sleepy
driving, and in return the drivers expressed concerns about their GPs lack of
screening for sleep complaints as part of their routine medical check-ups.
Driver 11:
I see my doctor 4 times a year minimum ... he’s never asked me
that question [sleep related]...
Driver 14 added:
Yeah the doctor never asks about sleep. Never!
Driver 16 said:
... [My doctor] might say to me, oh [it’s] this time of the
month, you haven’t had a prostate for 12 months, we’ll check you
over...If I was sleepy, I’d soon tell him that’s for sure. But
that’s a personal thing, I guess ...
From the comments, it appeared that doctors were generally
more concerned with evaluating the more familiar medical issues that could
affect a driver’s license renewal, such as visual acuity, hypertension,
and other medical conditions such as diabetes, but even these conditions were
not routinely assessed according to some drivers. Another facet of this problem
was that some drivers did not think to mention sleep-related issues as a health
concern, because they did not identify them as a priority, as illustrated by the
following example.
Driver 11:
You don’t even think to tell the doctor when you get there, you
don’t even think about it ... you worry about your eyesight and what not,
and so forth, not the sleeping business!
The overall impression obtained from the discussion was that
many of the drivers’ GPs are not well informed about sleepiness or sleep
complaints, nor do they routinely assess symptoms of OSAS.
AvoidanceThe second sub-theme, avoidance, was defined as a conscious
decision by drivers not to reveal health concerns to their GPs. The following
discussion illustrates this.
Driver 17:
You tell him [doctor], and then they’ll probably give you another
test or something else and that will delay your certificate of driving, and
that’s probably the worst thing...a delay of another week ... it might
delay you the last certificate for fitness, you know to go and get your licence,
you see what I mean?
Driver 15 added:
...yeah might open a can of worms
Driver 17 continued:
I mean if the doctor tells you ‘excuse me sir, you’re a
little bit overweight, try and lose some weight,’ you don’t want to
say ‘what about my sleeping disorder?’ ‘I feel a bit
tired!’ You don’t want to open up, you know? And I suppose all the
taxi drivers ... feel like that too.
The issues raised by these two drivers led others into a
group consensus. The first issue is withholding information in order to protect
their employment status. Both drivers described actively concealing any health
problems that might impact on their being assessed as medically unfit to drive.
This is understandable in the prevailing context where there was no standard
format for the fitness-to-drive screening of professional taxi drivers carried
out by GPs.
The second issue relates to withholding information from the
doctor for personal reasons. Driver 17 raised the point that drivers who are
overweight, and know that they have a sleeping problem, would not seek help from
the doctor because they would feel embarrassed. Other reasons for avoiding
seeing the doctor included both the cost of the consultation and any medications
prescribed, and the loss of income from being off the road to attend the
appointment.
Personal fearThe third sub-theme was personal fear. This was
characterised by drivers not wanting to believe that something is physically
wrong, or being apprehensive about finding out about further or more serious
health conditions that could compromise their ability to earn a living. A common
element in this sub-theme was mistrust of other people’s concerns about
the driver’s health.
Driver 17:
... I used to smoke until 3 years ago and my wife used to say
‘you snore a lot you might as well you know try and stop smoking’.
So three years ago I stopped but I’m still snoring [laughs with the
group]. ... It’s either your wife or somebody, your friend watching you
while you’re sleeping and they tell you that there’s something wrong
with your sleeping. But you never believe them because you don’t know what
you’re doing while you’re sleeping.
Fear of loss of income was a significant factor for the
participants, who face considerable day-to-day variability in income and very
limited alternatives for owner drivers if they get sick. One approach suggested
was to seek additional information (e.g. on the internet) to assess the possible
outcomes, before speaking to the doctor. This approach also avoids medical costs
(e.g., medication, specialists, and laboratory tests).
Driver 24:
If I knew I had apnoea and I was scared to go to the doctor because I
might lose my license I might get some information first [like searching the
internet or reading a book]. If apnoea was treatable then I’ll go and seek
help and treat it. If not, I’d probably shut up [laughs].
Taking time out from driving to look after personal needs
was identified with loss of income, although it was recognised that failing to
look after one’s self could lead to larger health problems in the long
term. Whether attributed to greed or need, this seemed to be accepted as part of
the ‘taxi culture’, because of the competitive nature of the
business.
Driver 20:
I mean not everyone is hard fetched for cash. Some people are just like
that you know. The first thing is to get another job ... maybe I’m wrong
but that’s how I look at it. A lot of people would do these things. They
don’t have any time for themselves. All they do is sit on the stand and
work and work and work, and after a certain time and unless people decide no
they have to make some times for themselves they have a problem and they got to
go and see a doctor. They have to make the time you know.
The themes identified above reflect attitudes which may
limit drivers’ ability to recognise and act on OSAS symptoms or other
sleep complaints. This raised the question of who they saw as being responsible
for their health and safety. Some believed that their GPs were responsible,
because they conduct the medical check-ups and provide a certificate,
effectively declaring drivers as ‘fit and safe’ to drive, whilst
others believed that the onus of responsibility lies heavily on the individual
driver.
DiscussionThis qualitative exploration of the attitudes of taxi
drivers at high risk for OSA has highlighted a number of areas where strategies
could be implemented to improve driver health and safety.
First, the lack of knowledge among drivers about the causes
of sleepiness, including OSAS, and the associated driving risk, points to the
need for better driver fatigue management education.
The National Road Safety Committee has developed an
inter-agency Driver Fatigue
Strategy.22 One of the deliverables in the
strategy is a commitment to providing ‘educative measures to assist
drivers to modify their behaviour to reduce the incidence of driver
fatigue’. In relation to commercial drivers, the Accident Compensation
Commission is charged with workplace delivery of ‘Managing Fatigue’
training and raising awareness with heavy motor vehicle drivers. In addition,
the New Zealand Land Transport Agency (NZLTA) is charged to ensure that the
fatigue section of the “Your Safe Driving Policy” resource reflects
the most up-to-date advice on managing fatigue.
From examining the NZLTA website in May 2009, advice for
companies developing a “Safe Driving Policy” indicated that the
policy must address driver fatigue, but fatigue management education was not
discussed among the recommended strategies. Nor was it listed as a course to
consider for driver training and education, although it was recommended that
regular staff seminars or refresher meetings should cover fatigue as one of a
number of listed topics.
With regard to the issues raised by the present study, it is
not clear whether any of these measures will reach taxi drivers, most of whom
either work as subcontractors or are self-employed, but pay dues to a taxi
company that provides communication services and branding.
Another option would be to include driver fatigue management
education as part of the approved course that drivers must undertake to get a
P-endorsement licence to carry paying passengers. This approach means that the
regulating authority takes responsibility for providing such education, but the
responsibility remains with the individual drivers to apply this knowledge in
their professional activity.
Fatigue management training has been shown to result in
better knowledge levels and (self-reported) improvements in personal fatigue
management strategies among professional tanker
drivers.23
Acknowledging the role of shift-work is important as well,
particularly as sleep becomes displaced from its usual night position, and this
can pose problems with neurobehavioral and cognitive performance.
Shift-workers tend to select their sleep-wake schedules
because of their work commitments and this disrupts the synchronisation of
internal sleep structure. This results in sleep deprivation, fragmented sleep,
and complaints of excessive daytime
sleepiness.24 The issues around shift-work,
sleep deprivation and other sleep disorders are a complex web of circadian,
sleep and social factors, with each influencing the other and impacting on the
ability to adapt and cope with daily
pressures.25 It is also outside the scope of
this study, but it is a necessary consideration in future research with
professional taxi drivers.
Second, in the experience of these focus group participants,
GPs did not routinely ask questions regarding sleepiness or OSAS symptoms, nor
did they demonstrate knowledge or awareness of sleep problems in general, or the
risks associated with sleepy driving. For example, some drivers were told that
sleepiness was part of the normal aging process, or that they just needed to
lose weight.16
These findings are consistent with previous
research,26–28 which has also highlighted
the need for continuing medical education programmes to up-skill GPs in sleep
medicine. One of the deliverables in the national Driver Fatigue Strategy is to
ensure that medical practitioners are aware of the effects of sleep deprivation
and its contribution to driver fatigue.22
The role of GPs is pivotal for managing taxi driver fatigue
issues, because of their established rapport with their regular patients,
especially since they act as a conduit for referral to specialist services for
OSAS treatment and diagnosis, and because follow-up management of OSAS patients
is often referred back to GPs. However, the relationship between taxi drivers
and their GPs is complicated by the fact that GPs also have the responsibility
for evaluating whether a driver is fit for work.
Both in the legally-required medical assessments for license
renewal, and if significant health concerns are identified between the required
assessments, a GP can notify the Chief Medical Advisor who may decide to suspend
a driver’s license. The drivers in the present study were acutely aware of
this and admitted to actively concealing any health problems that might impact
on their being assessed as medically fit to drive. Similar issues have been
reported with other groups of professional
drivers.13,14,27–29
Clearer guidance from the NZLTA about the criteria for being
considered medically unfit, and about returning to work subject to adequate
treatment, could help diffuse some of these concerns, if drivers and their GPs
knew about the criteria. Standardised forms for required medical assessments
might also improve drivers’ confidence and assist GPs in this process.
In the national Driver Fatigue Strategy, the NZLTA committed
to reviewing the relevant sections of its ‘Medical Aspects of Fitness to
Drive’ resource and related forms for medical practitioners, by December
2008. However, use of these resources is voluntary and it is unclear how many
GPs are aware of them, or use them. Another possibility would be to have the
fitness-to-drive medical assessments undertaken by trained occupational
physicians who are not the driver’s GP, as is the case for commercial
airline pilots.
With regard to ongoing management of professional drivers
with OSAS who are receiving treatment such as Continuous Positive Airway
Pressure (CPAP), one approach used in the UK (Rosemary Gibson, personal
communication, 2008) is to schedule an annual check-up at the sleep clinic,
which includes downloading the data collected by the CPAP machine about the
amount of time that it has been used. Threshold criteria for treatment
compliance can be then used to trigger different actions. For example, if a
driver’s usage rate is at least 80%, then the driver’s license can
be renewed.
If the usage rate is between 50-80%, the driver is required
to return for a further follow up at the sleep clinic in three months time.
Lower rates of usage could trigger a referral back to the sleep specialist. This
process could be reinforced by forwarding the names of non-compliant drivers to
the regulator, in the interests of public safety. However, in New Zealand,
funding for sleep apnoea services is directed at diagnosis and initial
follow-up.
There is no funding for long-term follow-up of patients on
CPAP due to limited resources (Dr Alister Neill, personal communication, 2008).
It might have been interesting to explore the acceptability of this approach
with drivers in the focus groups. However their lack of knowledge and experience
with OSAS treatment would have rendered this discussion very hypothetical.
To improve the identification, diagnosis, and management of
OSAS patients, additional research is needed to provide
reliable screening tools for GPs, and to clarify measures to
identify those individuals most likely to be at elevated risk for
MVAs.20 However, improvements in the
identification and referral of patients with OSAS at the primary care level
needs to be matched with an appropriate level and distribution of specialist
services nationwide.30
It would be also be useful to have a better understanding of
the knowledge and awareness levels among GPs. The current study invited a random
selection of GPs from the wider Wellington region to attend a focus group
discussion on these issues. However, only one GP responded favourably, others
were too busy to attend. At the time of this invitation, New Zealand GPs were
preparing to roll out a national strategy of immunising infants against
Meningococcal-B, which the responding GPs reported had higher priority.
Nevertheless, the role of GPs in managing professional
drivers with OSAS is an important one. Further emphasis on the doctor’s
role to advocate for this particular group of patients is necessary, and this
could be endorsed through professional development education workshops about
sleep and sleep related disorders.
Implications for public health policyThe Ministry of Transport and its respective transport
regulatory agencies, the Accident Compensation Corporation, and the Department
of Labour are working together through the National Road Safety
Committee’s inter-agency strategy to combat driver fatigue. One of their
key activities is raising awareness about the dangers of sleepy driving, for
both professional drivers and private motorists. This can be expected to reduce
the acceptability of professional drivers being sleepy at work, and increase the
demand for healthcare services to manage chronic sleep disorders, including
OSAS.
The Ministry of Health needs to become involved in strategic
planning of healthcare services to meet these needs. Taxi company managers also
need to be educated about, and enforce safe driving policies, so that individual
drivers feel supported and are reminded about adhering to such policies.
Competing interests: None.
Author information: Ridvan T Firestone,
Pacific Research Fellow; Philippa H Gander, Director; Sleep/Wake Research
Centre, Massey University, Wellington Acknowledgements: The
Health Research Council of New Zealand supported this study. The authors are
indebted to the drivers who participated in the study. Thank you also to Dr John
Matthewson for his assistance in recruitment and preliminary data analyses with
the focus groups. We also thank Dr Alister Neil who provided useful comments on
this paper.
Correspondence: Dr Ridvan Tupai Firestone,
Centre for Public Health Research, Massey University, Private Box 756,
Wellington, New Zealand. Fax: +64 (0)4 3800629; email: r.t.firestone@massey.ac.nz
References:
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