Transcript Document 7254305

Health and safety
Health Psychology
Statistics
• Government data reveal that accidental
injury is~
– 1. · the fourth most frequent cause of death in
the American population as a whole.
– 2. · The leading cause of death of individuals
under age 45.
– 3. · Responsible for over half of all deaths of
children and adolescents (Cataldo et al., 1986;
Haggerty, 1986; WaIler, 1987).
Definition
• Pheasant (1991) defines
an accident as “ an
unplanned unforeseen or
uncontrolled event –
generally one that has
unhappy consequences”.
Road accidents
• During 1999 there were just over 235,000
accidents causing personal injury, which
caused 320,000 casualties including 3,600
deaths. This actually shows a marked
improvement over the last twenty years, as
deaths and serious injuries have reduced by
36 per cent and 48 per cent respectively
since 1981
• (DETR, 1999).
Accidents in the home
• Around 4,300 people are killed each year in
home and garden accidents, and about
170,000 suffered serious injuries that
required inpatient treatment in hospital.
Home accidents also led to 2.84 million
visits to accident and emergency
departments.
Accidents at work
• Surveys indicate that about 1.5 million
people each year are hurt at work and
treated in casualty departments. Many of the
injuries are minor and so are not reported.
In 1998/9 there were just under 53,000
major injuries reported, of which 24,000
were to members of the public (R0SPA,
2001 a).
CAUSES OF ACCIDENTS
• In some respects all accidents are unique,
but it is also possible to see some common
contributory causes. Reason (2000) says
that the problem of human error can be
viewed in two ways: the person approach,
and the system approach. Each way has its
own model of the causes of error and
suggestions of what is to be done about it.
CAUSES OF ACCIDENTS
• The example below
of giving the wrong
medicine highlights
these two models.
The Wrong Medicine
• On the afternoon of January 4th 2001, a day
case patient at the Queens Medical Centre
(QMC) in Nottingham turned up for his
chemotherapy treatment. Under the
supervision of a Specialist Registrar, a
Senior House Doctor correctly gave the
patient a drug (Cytosine) directly into the
spine.
The Wrong Medicine
• A second drug (Vincristine) was then also
administered by the same route.
Unfortunately, this drug should have been
given intravenously, and despite the efforts
of the medical staff the 19-year-old patient
died.
The Wrong Medicine
• How could this happen? How could two
experienced, specialist doctors make what appears
to outsiders to be such a basic error? The inquiry
into the accident (D0H, 2001 d) highlights how
professional mistakes (personal causes of error)
and the procedures and equipment (system causes)
contributed to the death. It was already known that
there was a danger of giving Vincristine into the
spine because it had happened before.
The Wrong Medicine
• As a result it was part of good practice at the
QMC to give the two treatments — one into the
spine and one into a vein — on different days, but
this procedure was not always followed, especially
when patients had a history of missing
appointments. Also, the manufacturer of
Vincristine provided labels to be attached to the
syringes which said ‘Not for intrathecal use — For
intravenous use only. However the QMC staff did
not use these labels because they believed they
had the potential to confuse people.
The Wrong Medicine
• The inquiry also noted that the syringes for
both injections looked very similar and that
the labels were both in black type.
Unsafe behaviours / systems
• Accidents are caused
by either:
1.Unsafe behaviours or
2.Unsafe systems
Roberts and Holly (1996)
• Roberts and Holly (1996) list the basic causes of
accidents in hospital settings:
1. Inadequate work standards: through a lack of
training and supervision.
2. Inadequate equipment or maintenance of
equipment
3. Abuse or misuse of equipment, or failure to check
equipment.
4. Lack of knowledge (for example in not being able
to use equipment correctly.
•
Roberts and Holly (1996)
5. Inadequate physical or mental capacity to
do the required job.
6. Mental or physical stress
7. Improper motivation (e.g. Dr Shipman)
Deskilling
• A source of error in the relationship between
operators and machines is the deskilling of the
workers. Bainbridge (1987) referred to this as the
irony of automation. She pointed out that
designers view human operators as unreliable and
inefficient, and try to replace them wherever
possible with automated devices. Yet this policy
often leads directly to an increased number of
errors and accidents.
Deskilling
• The paralysis of the London Ambulance Service,
a direct result of the introduction of an automated
emergency call routing system in 1993, was a
classic example of how this type of problem
happens. There are two ironies here: the first is
that many mistakes come from the designer’s
initial errors — systems are introduced which
have not been properly worked out and which are
actually unable to do what is required of them.
Second, as Bainbridge points out, designers still
leave people to do the difficult tasks, which cannot
be automated so easily.
Cognitive overload
• The study of selective
attention highlights some
limitations on our ability
to process information.
An example of this
problem was reported by
Barber (1988), in a
description of an aircraft
accident in the area of
Zagreb, which was then
part of Yugoslavia.
Cognitive overload
• A British Airways Trident
collided with a DC-9 of
Inex Adria Airways,
resulting in the loss of
176 lives. One of the
factors identified as
leading to the collision
was the cognitive
overload of the air traffic
controller responsible for
the sector the planes were
flying in.
Cognitive overload
• At the time of the
accident the controller’s
assistant was missing,
there were eleven aircraft
in his sector, he was in
simultaneous radio
communication with four
other aircraft, and he was
taking part in a telephone
conversation with
Belgrade concerning two
further aircraft.
Cognitive overload
• The controller had
received very short notice
of the arrival of the DC-9
into his sector and it
appears that the short
notice and the overload of
information contributed
to the final error.
Nevertheless, he was
prosecuted and jailed.
Cognitive overload
• This is a graphic
illustration of the
limitations of our
information processing
capacities, and shows that
the public response to
disasters is often to blame
individuals, when it is the
systems within which the
individuals are working
which are actually at
fault.
Equipment design
• An illustration of the problem of equipment design
occurred during World War 11(1939—45), and it
came about because the US air force had
concentrated on training pilots to fly aircraft rather
than designing aircraft that could be flown by
pilots. They discovered, however, that even very
experienced pilots were prone to make errors with
the poorly designed control systems.
Equipment design
• For example, similar looking
controls operating the landing
gear and the steering flaps on
some B-25 bombers were
placed next to each other. The
unfortunate consequence of
this was that several B-25s
were brought into land without
the landing gear in place, and
so landed on their bellies.
Equipment design
• The pilots believed that they
had activated the landing gear,
but in fact they had just steered
the plane (Mark, Warm and
Huston, 1987). Observations
like this have led to the
development of aircraft
controls that more nearly
match the capabilities of pilots.
Causes of accidents
• Most accidents have multiple causes,
though we can divide many of them into
two basic categories:
• 1. Individual errors (unsafe behaviours)
• 2. Organisational errors (unsafe systems)
Causes of accidents
• Reason (1990), in his discussion of human error
presented a series of case studies of major
disasters. In each disaster, a situation was created
over a number of months or years, where the
systems introduced or neglected by management
finally produced a major incident. The incident
itself was triggered by the action of one or two
individuals and it was these individuals who
inevitably got the public blame while the
organisation remained relatively unscathed.
Causes of accidents
• In his description of the Herald of Free
Enterprise ferry disaster Reason (1990)
identified ten factors that contributed to the
sinking of the ship. He attributed all of them
to bad management decisions and design
problems, yet it was three sailors who were
punished while the management of the ferry
owners (P&O) avoided any sanctions.
Chain of events
and active
failures
Contributing
conditions and
latent failures
The Herald is docked
at No. 12 berth in
Zeebrugge’s inner
harbour, and is loading
passengers and
vehicles before
making the crossing to
Dover.
This berth is not capable of
loading both car docks [E and
G] at the same time, having only
a single ramp. Due to high water
spring tides, the ramp could not
be elevated sufficiently to reach
L dock. To achieve this, it was
necessary to trim the ship
nosedown by filling trim ballast
tanks Nos. 14 and 3. Normal
practice was Lu start filling No.
14 tank 2 hours before arrival.
(System failure)
At 18.05 on 6 March
1987, The Herald goes
astern from the berth,
turns to starboard, and
proceeds to sea with both
her inner and outer bow
doors fully open
The most immediate cause is that the
assistant boson (whose job it was to
close the doors) was asleep in his
cabin, having just been relieved from
maintenance and cleaning duties.
(Supervisory failure and unsuitable
rostering)
The boson, his immediate superior,
was the last man to leave G dock. He
noticed that the bow doors were still
open, but did not close them, since he
did not see that as part of his duties.
(Management failure)
Herald of
Free
Enterprise
Chain of events
and active
failures
Contributing
conditions and
latent failures
Chief officer
checks that
there are no
passengers on G
dock, and thinks
he sees assistant
boson going to
close doors
(though
testimony is
confused on this
point).
The chief officer, responsible for
ensuring door closure, was also
required (by company orders) to
be on the bridge 15 minutes
before sailing time.
(Management failure)
Because of delays at Dover,
there was great pressure on
crews to sail early. Memo from
operations manager: ‘Put
pressures on your first officer if
you don't think he’s moving fast
enough… sailing late out of
Zeebrugge isn't on. It's 15
minutes early for us.’
(Management failure)
Company standing orders
(ambiguously worded) appear to
call for negative reporting only.
If not told otherwise, the master
should assume that all is well.
Chief officer did not make a
report, nor did the master ask
him For one.
Herald of
Free
Enterprise
Chain of events
and active
failures
Contributing
conditions and latent
failures
On leaving
harbour, master
increases speed.
Water enters
open bow doors
and Floods into
C deck At
around 18.27,
Herald capsizes
to port.
Despite repeated requests from
the masters to the management,
no bow door indicators wore
available on the bridge, and the
master was unaware that he had
sailed with bow doors open.
Estimated cost of indicators was
£400-500.
(Management failure)
Ship had chronic list to port.
(Management and technical
failure)
Scuppers inadequate to void
water from flooded G deck.
(Design and maintenance
failure)
Top-heavy design of The Herald
and other ‘ro ro' ships in its class
was inherently unsafe.
(Design failure)
Source: Reason, 1990
Herald of
Free
Enterprise
Human error
• Riggio (1990) identified four types of error that
can lead to accidents:

1 Errors of omission: failing to carry out a task;
for example, not closing the bow doors on the ferry in
Zeebrugge harbour

2 Errors of commission: making an incorrect
action, for example, a health worker giving someone
the wrong medicine

3 Timing errors: working too quickly, working
too slowly

4 Sequence errors: doing things in the wrong
order
The negative consequences to an
individual of reporting a personal
error or accident include:

· time lost

· feeling guilty

· admitting mistakes

· possible disciplinary action

· possible lost confidence of
colleagues

· making a mountain out of molehill.
The problems for management of
receiving an accident report
include:

· having a written record of the event
which increases the danger of litigation

· increased need for action by
management

· increased need for investment in
people Or equipment

· responsibility is shifted from the
worker to the organisation.
Factors affecting organisational
error
•
•
•
•
1. · the selection of inappropriate staff
2. · poor working procedure
3. · duty rotas that lead to fatigue
4. · an organisational climate that creates
poor morale
• 5. · inadequate equipment for the task
• 6. · inadequate levels of training.
Factors affecting individual
error
I Substance and alcohol abuse
• The most commonly cited cause of accidents is
alcohol or substance abuse. When chemicals
impair our judgement we are more likely to
underestimate the risks of a situation, and
overestimate our ability to deal with it. A study of
over 500 people attending accident and emergency
departments in Scotland examined levels of
alcohol (Simpson et a/. 2001).
Factors affecting individual
error
I Substance and alcohol abuse
• About 25 per cent of the attendees showed signs
of alcohol. It was especially noticeable in people
attending for reasons of self-harm (95 per cent),
collapse (47 per cent) assault (50 per cent), and in
those who were subsequently admitted to the
hospital (50 per cent). These figures suggest that
alcohol might well be a factor in a range of
accidents that lead to serious injury. A less well
researched area is the effect of prescription drugs
on performance.
Factors affecting individual
error
I Substance and alcohol abuse
• In Britain the Department of Transport (1996)
carried out an analysis of data on road traffic
accidents in which one or more of the drivers
involved either failed or refused a breath or blood
test. In 1996 there were 10,850 drink-drive
accidents including 540 deaths. Pedestrians who
are killed in road accidents are also likely to have
been drinking.
Factors affecting individual
error
I Substance and alcohol abuse
• In an earlier report (Department of Transport,
1992), it was estimated that about half of
pedestrians aged between 16 and 60 killed in road
accidents had more alcohol in their bloodstream
than the legal drink-drive limit. This fact is
certainly supported in any driver’s experience of
travelling through urban areas after pub closing
time at night.
Factors affecting individual
error
I Substance and alcohol abuse
• Studies conducted in a number of countries
indicate that alcohol is implicated in many
attendances at hospital accident and emergency
departments (Cherpitel, 1993; Waller et al., 1998).
Williams et al. (1994) reported that 50% of adults
admitted to a hospital surgery unit with a head
injury were obviously drunk. Alcohol has been
shown to play a significant role in deaths from
falls, fires, industrial accidents and deaths from
drowning (Eckhardt et al., 1981; Plueckhan, 1982;
Tether and Harrison, 1986).
Factors affecting individual
error
I Substance and alcohol abuse
• Drunk driving is a major cause of death in the
United States: about one-half of the nearly 40,000
deaths each year in automobile accidents are
associated with alcohol use; fortunately, the
number of motor vehicle deaths and those related
to alcohol use have declined greatly since the early
1980s (Tolchin, 1993). Consuming alcohol
impairs cognitive, perceptual, and motor
performance for several hours; particularly the
first 2 or 3 hours after drinks are consumed.
Factors affecting individual
error
I Substance and alcohol abuse
• The degree of impairment individuals
experience can vary widely from one person
to the next and depends on the rate of
drinking and the person’s weight. The table
gives the average impairment for driving—
but for some people, one or two drinks may
be too many to drive safely.
Factors affecting individual
error
I Substance and alcohol abuse
Factors affecting individual
error
I Substance and alcohol abuse
• Barbone et aI. (1998) looked at the medical
records of drivers in Scotland involved in their
first car accident over a three-year period to
identify how many had been prescribed
psychoactive drugs such as tranquillisers (for
example, benzodiazepines) and antidepressants.
There were 19,400 drivers involved in accidents in
that period, of which over 1,700 were on some
form of psychoactive medication, most commonly
benzodiazepines.
Factors affecting individual
error
I Substance and alcohol abuse
• They concluded that users of
benzodiazepines had a 60 per cent higher
risk of having a first traffic accident and
should be advised not to drive.
Factors affecting individual
error
Lack of sleep
• It is a robust finding from sleep research that sleep
deprivation affects people so that they (a) make
more errors, and (b) need longer to complete a
task (Asken, 1983). One particular area of concern
is sleep-related vehicle accidents (SRVAs). A
substantial survey of 4,600 UK drivers found that
29 per cent admitted to having felt close to falling
asleep at the wheel during the previous 12 months
(Maycock, 1996). Sleepiness is brought on by
long, undemanding, monotonous driving, such as
on a motorway.
Factors affecting individual
error
Lack of sleep
• It is also, not surprisingly, affected by the time of
day, as our bodily rhythms affect our level of
arousal and alertness. One of the problems for
drivers who are feeling sleepy is they are often not
aware of dropping off for a few seconds. It is a
general finding from sleep research that people
who are woken within a minute or two of falling
asleep commonly deny having been asleep (Home
and Reyner, 1999).
•
Factors affecting individual
error
Lack of sleep
Factors affecting individual
error
Accident proneness
• This is controversial, since it stigmatises some
individuals, though there is some research that
suggests accident proneness can be identified.
Jones and Wuebker (1988) describe how a
personnel inventory can be used to predict a
number of accident-related events. Using the
questionnaire they were able to identity high-risk
individuals on the basis of their attitudes and
personality, and to place them in less hazardous
positions, or place them on special safety training
programmes.
Factors affecting individual
error
• Other factors that might affect accidents
include recent stressful life events, and fear
of mistakes
The end