A new stratified risk assessment tool for whiplash injuries developed from a prospective observational study

Abstract

Objectives An initial stratification of acute whiplash patients into seven risk-strata in relation to 1-year work disability as primary outcome is presented.
Design The design was an observational prospective study of risk factors embedded in a randomised controlled study.
Setting Acute whiplash patients from units, general practitioners in four Danish counties were referred to two research centres.
Participants During a 2-year inclusion period, acute consecutive whiplash-injured (age 18–70 years, rear-end or frontal-end car accident and WAD (whiplash-associated disorders) grades I–III, symptoms within 72 h, examination prior to 10 days postinjury, capable of written/spoken Danish, without other injuries/fractures, pre-existing significant somatic/psychiatric disorder, drug/alcohol abuse and previous significant pain/headache). 688 (438 women and 250 men) participants were interviewed and examined by a study nurse after 5 days; 605 were completed after 1 year. A risk score which included items of initial neck pain/headache intensity, a number of non-painful complaints and active neck mobility was applied. The primary outcome parameter was 1-year work disability.
Results The risk score and number of sick-listing days were related (Kruskal-Wallis, p<0.0001). In stratum 1, less than 4%, but in stratum 7, 68% were work-disabled after 1 year. Early work assessment (p<0.0001), impact of the event questionnaire (p<0.0006), psychophysical pain measures being McGill pain questionnaire parameters (p<0.0001), pressure pain algometry (p<0.0001) and palpation (p<0.0001) showed a significant relationship with risk stratification.
Analysis Findings confirm previous studies reporting intense neck pain/headache and distress as predictors for work disability after whiplash. Neck-mobility was a strong predictor in this study; however, it was a more inconsistent predictor in other studies.
Conclusions Application of the risk assessment score and use of the risk strata system may be beneficial in future studies and may be considered as a valuable tool to assess return-to-work following injuries; however, further studies are needed.

Full text

Anewstratified risk assessment tool for
whiplash injuries developed from a
prospective observational study
Helge Kasch,
1
Alice Kongsted,
2
Erisela Qerama,
3
Flemming W Bach,
4
Tom Bendix,
5
Troels Staehelin Jensen
1
To cite: Kasch H,
Kongsted A, Qerama E, et al.
A new stratified risk
assessment tool for whiplash
injuries developed from a
prospective observational
study. BMJ Open 2013;3:
e002050. doi:10.1136/
bmjopen-2012-002050
▸
Prepublication history and
additional material for this
paper are available online. To
view these files please visit
the journal online
(http://dx.doi.org/10.1136/
bmjopen-2012-002050).
▸ Additional material is
published online only. To
view please visit the journal
online (http://dx.doi.org/10.
1136/bmjopen-2012-
002050).
Received 17 September 2012
Revised 29 December 2012
Accepted 9 January 2013
This final article is available
for use under the terms of
the Creative Commons
Attribution Non-Commercial
2.0 Licence; see
http://bmjopen.bmj.com
For numbered affiliations see
end of article.
Correspondence to
Dr Helge Kasch;
helge.kasch@dadlnet.dk
ABSTRACT
Objectives:
An initial stratification of acute whiplash
patients into seven risk-strata in relation to 1-year work
disability as primary outcome is presented.
Design: The design was an observational prospective
study of risk factors embedded in a randomised
controlled study.
Setting: Acute whiplash patients from units, general
practitioners in four Danish counties were referred to
two research centres.
Participants: During a 2-year inclusion period, acute
consecutive whiplash-injured (age 18–70 years, rear-
end or frontal-end car accident and WAD (whiplash-
associated disorders) grades I–III, symptoms within
72 h, examination prior to 10 days postinjury, capable
of written/spoken Danish, without other injuries/
fractures, pre-existing significant somatic/psychiatric
disorder, drug/alcohol abuse and previous significant
pain/headache). 688 (438 women and 250 men)
participants were interviewed and examined by a study
nurse after 5 days; 605 were completed after 1 year. A
risk score which included items of initial neck pain/
headache intensity, a number of non-painful
complaints and active neck mobility was applied. The
primary outcome parameter was 1-year work disability.
Results: The risk score and number of sick-listing
days were related (Kruskal-Wallis, p<0.0001). In
stratum 1, less than 4%, but in stratum 7, 68% were
work-disabled after 1 year. Early work assessment
(p<0.0001), impact of the event questionnaire
(p<0.0006), psychophysical pain measures being
McGill pain questionnaire parameters (p<0.0001),
pressure pain algometry ( p<0.0001) and palpation
(p<0.0001) showed a significant relationship with risk
stratification.
Analysis: Findings confirm previous studies reporting
intense neck pain/headache and distress as predictors
for work disability after whiplash. Neck-mobility was a
strong predictor in this study; however, it was a more
inconsistent predictor in other studies.
Conclusions: Application of the risk assessment
score and use of the risk strata system may be
beneficial in future studies and may be considered as a
valuable tool to assess return-to-work following
injuries; however, further studies are needed.
INTRODUCTION
Chronic pain represents a major problem in
the Western world with approximately 20%
of the adult population suffering from
chronic pain. Our ability to deal with these
chronic pain conditions is insufficient as it is
in various other areas, such as traumatic
injuries and pain following surgery or other
medical procedures. Identifying patients at
risk of developin g chronic pain is a pre-
requisite for establishment of prophylactic
initiatives.
When discussing pain following surgery, it
has been demonstrated that prior pain
ARTICLE SUMMARY
Article focus
▪ In an observational study of acute whiplash
patients performed earlier, we identified risk
factors which provided a risk assessment score.
▪ The risk assessment score was applied in a new
1-year longitudinal multicentre cohort study of
acute whiplash patients with a main outcome
parameter of a 1-year work disability.
Key messages
▪ Significant relation was found between the risk
assessment score and 1-year work disability.
Stratification early after whiplash injury into
seven risk strata was furthermore supported by
other findings concerning psychological, social,
work-related and psychophysical pain measures.
▪ The Risk Assesment Score may be considered a
valuable tool for assessment of work disability in
future studies.
Strengths and limitations
▪ Initially, risk factors were identified in an obser-
vational study and then applied and validated in
this multicentre study. To further validate find-
ings, other researchers should apply the risk
assessment score and the seven strata stratifica-
tion system on other populations for further
external validation.
Kasch H, Kongsted A, Qerama E, et al. BMJ Open 2013;3:e002050. doi:10.1136/bmjopen-2012-002050 1
Open Access Research

intensity, the duration of pain, the type of surgery, the
nerve damage during surgery as well as psychological
factors, information and the setting and the genetic
endowment are of significant importance with respect to
the future development and persistence of chronic
pain.
1–5
Also, regarding musculoskeletal pain conditions,
such as headache,
6
cervical sprains
7
and low back pain,
8
there is an interest in exploring the potential risk factors
aligned with persistent pain. The specific type of distor-
tion of the cervical spine, stemming from a so-called
whiplash injury, in which the neck spine is exposed to a
forced extension-flexion trauma, is often followed by a
late pain state known as whiplash-ass ociated disorders
(WAD).
910
These injuries may be associated with a reduction of
the pain threshold to mechanical pressure in the neck
muscles,
11 12
a reduction of nociceptive flexion
reflexes
13
and an expansion of cutaneously referred
pain symptoms following the infusion of hypertonic
saline into the muscles both at the injury site and in
areas remote from the injury site.
14
These findings
suggest generalised hyper-excitability following a whip-
lash injury, which resolves in patients recovering after
injury but persists in patients with ongoing symp-
toms.
21115–17
Whiplash-associated disorders fall into the categories
O–IV according to the Quebec WAD grading.
9
In a pre-
vious observational study, we found that a risk score
based on neck pain, headache, the number of non-
painful symptoms and reduced neck mobility was asso-
ciated with a marked risk of reduced recovery.
18
Based
on these observations, the objective of this study was to
test a stratified risk assessment scoring system for predict-
ing long-term sequelae after a whiplash injury. A risk
index was developed in a previous cohort and the pre-
dictive capability of seven risk strata tested.
18 19
In the
present study, we test whether the seven risk strata are
useful for prediction of outcome in that second sample.
In addition, differences in psychological and social
factors across the strata are described.
MATERIALS AND METHODS
Study overview
A risk stratification index based on the measures of
intensity of neck pain and headache, cervical range of
motion (CROM) and number of non-painful complaints
was developed in a previous sample of whiplash injured
seen in an emergency care unit.
18
Using a pragmatic
approach, seven risk strata were formed and this stratifi-
cation was strongly associated with outcome.
19
In the present study, these risk strata are tested in
another sample enrolled between May 2001 and June
2003. The study concludes a secondary analysis of two
parallel randomised controlled trials.
20 21
Patients were
enrolled within 10 days of a whiplash injury. Those with
a low-risk stratification index score were randomised to
either oral or written advice to act as usual,
20
whereas
patients with high-risk scores were randomised to immo-
bilisation (semi-rigid neck collar), active mobilisation
(McKenzie technique) or an oral recommendation to
act as usual
21
(figure 1). The oral and written advices
were delivered at the day of inclusion. The neck collar
and active mobilisation interventions involved contact
with a physical therapist for a maximum of 6 weeks.
Details about the interventions are reported else-
where.
20 21
No significant differences in treatment
effects were demonstrated and participants are therefore
considered in one cohort for the present study. The
study was approved by the local ethical committees (The
Scientific Committee for The Counties of Vejle and
Funen, Project number 20000268) and conducted in
accordance with the Helsinki II Declaration.
Study population
The cohort has been previously described.
11 20–22
In short,
persons with complaints from the neck and/or shoulder
girdle (WAD grade I–III) seeking care at an emergency
unit or a general practitioner within 72 h after a motor
vehicle collision were potential participants. Other inclu-
sion criteria were the following: age 18–70 years, exposure
to a rear-end or frontal-end car accident and that an exam-
ination could be performed within 10 days after the injury.
Exclusion criteria were inability to read and speak Danish,
injuries with fractures or dislocations (WAD grade IV),
Figure 1 Flowchart for the whiplash study.
2 Kasch H, Kongsted A, Qerama E, et al. BMJ Open 2013;3:e002050. doi:10.1136/bmjopen-2012-002050
Risk assesment score in whiplash injuries

additional trauma other than the whiplash injury, pre-
existing significant somatic or psychiatric disease, known
active alcohol or drug abuse and significant headache or
neck pain (self-reported average pain during the preced-
ing 6 months exceeding 2 on a 0–10 box scale, 0=no pain;
10=worst possible pain).
Risk Stratification Index measures
Pain: neck pain and headache since the collision were
scored on an 11-point Numeric Rating Scale (0=no pain;
10=worst imaginable pain).
23 24
Non-painful complaints: participants were asked whether
any of the 11 non-painful complaints (paresthesia, dizzi-
ness, vision disturbances, tinnitus, hyperacusis, dyspha-
gia, fatigue, irritation, concentration disturbances,
memory difficulties and sleep disturbances) had started
or been markedly worse since the accident.
Active neck mobility: total CROM including flexion, exten-
sion, right and left la teral-fle xion and right and left rota tion
was assessed with a CROM device as formerly described.
22 25
Risk stratification was performed by combining scores
on pain intensity, CROM and a number of non-painful
complaints.
19
Each factor was categorised and scored as
follows.
The highest score of neck pain and headache was
categorised into 0–2=0 points; 3–4=1 point; 5–8=4
points; 9–10=6 points.
Total active CROM was divided into: below 200°=10
points; 200–220=8 points; 221–240=6 points; 241–260=4
points; 261–280=2 points and above 280=0 points.
Number of non-painful complaints:0–2=0 points; 3–5=1
point and 6–11=3 points.
The following stratification was made: stratum 1=0
points; stratum 2=1–3 points; stratum 3=4–6 points;
stratum 4=7–9 points; stratum 5=10–12 points; stratum
6=13–15 points and stratum 7=16–19 points (see table 1
for overview).
Outcome measures
Follow-up questionnaires were posted to participants
after 3, 6 and 12 months. Beside data on sick leave, only
12 months’ follow-up was used for the present study.
The primary outcome measure
The primary outcome variable selected a priori was
1-year work disability, which was defined as: (1) sick
leave> 3 months during the last 6 months; (2) work
inability during the entire last month or (3) not working
anymore because of the accident.
18
The number of days on sick leave was computed by
means of a completed diary (a patient log) and ques-
tionnaire data after 3, 6 and 12 months postinjury. Days
with sick leave counted as full days and days with
reduced working hours counted as half days of sick
leave. If the patient could manage a full-time job but
had changed functions after injury, it counted as full
working hours. Patients who did not work prior to the
injury (on leave, unemployed, disability pension,
retired) were not considered in the calculated risk of
1-year work disability but were included in computation
of the secondary outcome measures, which have been
described elsewhere.
20 21
Other outcome measures
Work-related factors: expected difficulties with work were
measured by asking ‘How big a problem do you expect
it to be to take care of your job/study 6 weeks from
now?’ (0=no problem at all; 10=a very big problem,
cannot work), and ‘How likely do you consider it that
you will be working/studying 6 weeks from now?’
(0=very likely; 10=very unlikely). Self-rated physical work
demands were registered asking: ‘How physically
demanding do you consider your present/most recent
job’ (0=not physically demanding at all; 10=very physic-
ally demanding).
Post-traumatic stress response was measured by means
of the Impact of Event Scale (IES).
26
A total sum-score
was calculated from all 15 items of the scale. In addition,
an intrusion score (sum of 7 items) and an avoidance
score (sum of 8 items) were calculated.
Pressure algometry: the hand-held Algometer
(Somedic Algometer type 2) was applied with a slope of
30 kpa/s and a probe area of 1.0 cm
2
; pressure pain-
detection thresholds were measured in triplets, whereas
Table 1 The Danish whiplash study group risk assessment score
The Danish whiplash study group risk assessment score
Points 0 1 2 3 4 5 6 7 8 9 10
CROM >280 261–280 241–260 221–240 200–220 <200
Neck/head VAS 0–23–45–89–10
Number of non-pain symptoms 0–23–56–11
Stratum 1 0 points
Stratum 2 1–3 points
Stratum 3 4–6 points
Stratum 4 7–9 points
Stratum 5 10–12 points
Stratum 6 13–15 points
Stratum 7 16–19 points
CROM, cervical range of motion; VAS, visual analogue scale.
Kasch H, Kongsted A, Qerama E, et al. BMJ Open 2013;3:e002050. doi:10.1136/bmjopen-2012-002050
3
Risk assesment score in whiplash injuries

pressure pain-tolerance thresholds were measured by
one application of pressure only.
11
Methodical muscle palpation was performed bilat-
erally at nine sites: (1) the anterior part of the temporal
muscle, (2) the posterior part of the temporal muscle,
(3) the masseter muscle, (4) the lateral pterygoid
muscle, (5) the sternocleid at the mastoid insertion
point, (6) the sternocleid at its middle belly, (7) the sub-
occipital muscle group, (8) the superior trapezius
muscle and (9) the rhomboid muscle along the medial
border of the scapula. At each palpation site, a pain
score (0–4) was obtained
11 27
with
▸ 0 Equalling neither pain nor reported tenderness;
▸ 1 Equalling complaints of mild pain but no facial
contortion (grimace), flinch or withdrawal;
▸ 2 Equalling a moderate pain and degree of facial
contortion (grimace) or flinch;
▸ 3 Equalling a severe pain and marked flinch or
withdrawal and
▸ 4 Equalling unbearable pain and withdrawal without
palpation.
Statistical analysis
Data analyses were made with Stata V.12.0 (StataCorp,
Texas, USA) and Microsoft Excel 2010 for Windows. The
non-parametric Kruskal-Wallis test was applied for ana-
lysis of the strata. Parametric data with normal distribu-
tion or log normal distribution were presented within
each risk stratum graph as mean±SEM values. Receiver
operating characteristic (ROC) curves are given for
applied individual factors in the risk assessment score
(see online supplementary figure S1), and sensitivity,
specificity and positive and negative Likelihood
ratios were computed for each stratum for 1-year work
disability (refer to online supplementary table S2).
Two-way analysis of variances (ANOVAs) were applied for
testing eventual variability difference between centres
for the clinical measures.
Variability: palpation, pressure algometry and cervical
range of motion measurement were standardised at
group meetings during the observation period to reduce
eventual intertester and intratester variability.
RESULTS
Details of the study population have been described pre-
viously; a flow chart is presented in figure 1.
22
Briefly, a
total of 1495 (F/M: 898/597) acute whiplash patients
were contacted after being examined at the emergency
units or by their general practitioners. A total of 688 eli-
gible acute whiplash patients (F/M 443/252) gave
informed written and verbal consent to participate. Of
these, 30 were unemployed but considered capable of
working before injury, and 10 were either retired or on
disability pension and were not considered in primary
but only secondar y outcome measure (social factors are
tabulated in ref 22).
Two hundred (F/M: 102/98) patients refused to par-
ticipate. In total, 592 patients were not eligible, and 15
were excluded due to protocol violation (under-
reporting of previous neck pain, visual analogue scale
(VAS)>5 n=8; wrong initial group allocation in treatment
study, n=7).
Risk strata
Figure 2A shows a log-linear relationship between the
risk assessment score and the number of days being sick
for acute whiplash patients.
Figure 2B shows distribution in the risk strata after
1 year of patients (1) returning to work or (2) having
reduced functional capacity in full-time jobs or (3)
being work disa bled. Although 96% had returned to
work in stratum 1, only 32% of previous healthy
whiplash-exposed in stratum 7 were back at work after
1 year (Kruskal-Wallis, p<0.0001).
In figure 3A–C, the ability to perform work within
6 weeks and the ability to return to work within 6 weeks
and the assessment of the physical demands of their
present/recent job were rated after 5 median days on an
NRS-11-point box scale. Job-related issues were
Figure 2 (A) Risk strata and the number of sick-listed days
during the first year after whiplash injury. (B) One year
recovery from whiplash injury in risk strata.
4 Kasch H, Kongsted A, Qerama E, et al. BMJ Open 2013;3:e002050. doi:10.1136/bmjopen-2012-002050
Risk assesment score in whiplash injuries

increasingly severe in the higher risk stratum of the
patient (Kruskal-Wallis, p<0.0001).
The components of the impact of event scale in figure 4
intrusion and avoidance and the total IES score were bar-
graphed for each stratum. There was an increase in
reported injury-related emotional distress in the risk strata
(Kruskall-W allis, p<0.0001).
Figure 5A–D display the bar graphs of strata represent-
ing pressure algometry for both pain-detection thresh-
olds and pain-tolerance thresholds for the muscles in
the neck region: the masseter and the infraspinatus
muscles and at a remote control site at the left third
finger joint. All these psychophysical measures are differ-
ently distributed in the risk strata (K ruskall-Wallis ,
p<0.0001).
The total palpation score was similarly distributed and
significantly different in risk strata (Kruskall-Wallis
p<0.0001) with a score of 6 in stratum 1 and 24 in
stratum 7 (refer to online supplementary figure S2).
The Copenhagen Neck Disability Index score after
1 year was significantly related to risk strata
(Kruskall-Wallis , p<0.0001), and the 1-year 11-point box
scores of shoulder–arm pain, and neck pain, headache
and global pain were significantly related to risk strata
(p<0.0001) as well as all McGill Pain Questionnaire
derived pain-rating indices (PRI-T; PRI-S, PRI-A, PRI-E,
PRI-M) and number of word count (Kruskall-Wallis,
p<0.0001) .
Multicentre implications
There were no significant differences regarding the dis-
tribution of age, gender and strata, as well as the risk
measures of CROM (ANOVA, p>0.19), VAS neck/
Figure 4 The impact of event scale with subscales of
intrusion and avoidance shown in risk strata.
Figure 5 (A) Pressure algometry in the neck and head and
remote from injury in risk strata. (B) Pressure algometry in the
neck and head and remote from injury in risk strata. (C)
Pressure algometry in the neck and head and remote from
injury in risk strata. PPT pressure pain tolerance threshold
and PPDT pressure pain detection threshold (Kilo Pascal,
Mean±SEM), (D) Pressure algometry in the neck and head
and remote from injury in risk strata.
Figure 3 Initial numeric rating of work related issues in risk strata. (A) Expecting problems managing one’s job/education in
6 weeks. (B) likelihood of being back to work/education in 6 weeks and, (C) evaluation of the physical job requirement of the
current or most recent job/education.
Kasch H, Kongsted A, Qerama E, et al. BMJ Open 2013;3:e002050. doi:10.1136/bmjopen-2012-002050 5
Risk assesment score in whiplash injuries

headache (ANOVA, p>0.20) and non-painful symptoms
(ANOVA, p>0.58). However, there were differences in
intertester variability for total palpation (ANOVA,
p<0.001) and pressure algometry (p<0.01).
Embedded in treatment study
The present study was embedded in a treatment study in
which patients were divided into low-risk and high-risk
treatment groups (figure 1). A stratified analysis of the
seven strata, split into low-risk and high-risk groups,
yielded no difference on 1-year work disability based on
their given treatment (K-W p>0.15 for patients in the
high-risk group; p>0.91 for low-risk patient s).
DISCUSSION
This study shows that an early classification of patients
into risk strata based on biological and certain psycho-
social functions predicts non-recovery. In order to group
patients into seven different strata, we used a scaling
system resulting from observational findings from a
former study. This system included four predefined cat-
egories: neck pain intensity, headache intensity, the
number of non-painful symptoms and reduced neck
mobility. The strata set in the present study were applied
in clinical procedures undertaken at a time point where
chronic symptoms could not have developed, that is,
<median 5 days after injury. The scoring on neck mobil-
ity and non-painful symptoms was based on previous
observations where a control group was included.
19
The
summation score was arbitrarily determined, and it may
be argued that if another scoring had been used, other
findings might have been ascertained. Nevertheless, the
scoring was derived from the findings from a prospective
observational study of acute whiplash patients (WAD
I–III) with an ankle-injured control group in which
active neck mobility was the most significant predictor
for 1-year work disability.
18
Neck pain/headache inten-
sity, as well as a high number of non-painful complaints,
was also predictive, though to a lesser extent,
18
similar to
the present findings (see ROC curves in online supple-
mentary figure S1 A– D). In the present work and in our
previous studies,
18
we used return-to-work and number
of days parameters with sick leave of 1 year as indicators
of 1-year work disability. The use of sick leave as a par-
ameter of non-recover y has been discussed previously.
18
It may be argued that sick leave is not a direct measure
of non-recovery. But as for subjective symptoms such as
pain, it is crucial to select robust and directly quantifi-
able factors in order to reduce the risk of investigator
bias. Moreover, the fact that all measures concluding the
risk assessment score were completed shortly after injury
means that patients were in all probability prevented
from changing their habitual, preinjury health belief,
which could have been affected by various sources, like
the mass media, healthcare persons, family or
friends.
24 28
Furthermore, patients were not informed or made
aware of whether they belonged to a high-risk or a
low-risk group, and factors for the risk assessment score
were obtained before randomisation. Biological
responses like neck strength, duration of neck move-
ment
19
and psychophysical-like muscle tenderness by
palpation and pressure algometry and the coldpressor
pain response,
19
as well as stressful parameters like fear
avoidance and intrusion parameters and work-related
issues, are logically distributed in the risk strata. We did,
however, find intertester variability for algometry and
palpation, which may need more attention than we
offered in this setting (see Methods section), and which
has been reported in other studies.
29 30
CROM, VAS
neck pain/headache and the number of non-painful
symptoms did, however, not show unacceptable variabil-
ity in the current study.
The present risk stratification scheme rests on a
selected and limited number of symptoms and signs
based on prior observed findings. Legislative and
detailed psychosocial factors were not included in the
stratification. Such factors might also have an impact,
although the chances are that legislative issues hardly
affect recovery as early as 5 days after injury. There may
be other possible factors that can affect recovery.
31
In
the present paper, we suggest a way of stratifying whip-
lash patients in the acute state in order to improve the
predictive power of prognosis. Although the risk strata
presented here need to be tested as prognostic factors in
other cohorts in order to validate our findings, the
present study is one of the largest materials in the litera-
ture. Moreover, the system has not yet been tested in
relation to its possible usefulness in guiding clinical deci-
sions about the choice of treatment. It is a possible
downside to risk assessment that healthcare professionals
could make premature or hasty decisions when faced
with a certain patient who scores high on a prognostic
scale like ours. With such scorings, healthcare profes-
sionals might unconsciously associate the patient’s injury
with a prognosis of the chronicity type and act accord-
ingly to some extent. The Quebec Task Force’sWAD
grading represented a first attempt to better characterise
and identify patients at risk for long-term consequences
after a whiplash injury. However, subsequent studies
demonstrated that the Quebec WAD grading was of little
value in predicting long-term sequelae.
932
More recent
prospective papers have stressed the importance of em o-
tional distress, and social factors as risk factors for
reduced recovery,
33
post-traumatic stress disorder
(PTSD),
15 33
catastrophising,
34
kinesiophobia
28 31 35
and
stress-response
36
are factors associated with the risk of
persistent complaints. A trajectory system has been pro-
posed by Sterling et al
15
including four groups from no
pain/disability to severe pain/disability, in accordance
with post-traumatic stress, which ne eds further valid-
ation. It is generally agreed upon that there is a need
for studies confirming and validating prognostic models
and a need for improved models after acute WAD.
37
6 Kasch H, Kongsted A, Qerama E, et al. BMJ Open 2013;3:e002050. doi:10.1136/bmjopen-2012-002050
Risk assesment score in whiplash injuries

Other studies have found post-traumatic stress,
15
as well
as the presence of sensitisation
38
and neck pain and
headache intensities to be predictive of chronic neck dis-
ability 1 year after injury.
10 39
These findings are consist-
ent with the present results. Expectations for recovery
40
perceived injustice after the accident.
41
Reduced active
neck mobility has assumed importance in some, but not
a majority of, prospective studies.
42
It is of interest when
the CROM test, on its own, reaches an area under the
ROC curve of 0.79 (CI 95 075 to 0.85) (see online sup-
plementary figure S1 B) in this multicentre study in a
prediction of 1-year work disability. A critical view on
design, taking other risk factors into account, is however
also needed for future prediction studies that are highly
needed in the whiplash area.
37
CONCLUSION
The risk assessment score is applicable and inexpensive.
The early identification of whiplash-exposed persons at
risk for chronic pain and work disability is important for
planning future treatment in scientific studies.
More research is needed at present, but risk stratifica-
tion might have a place in the clinic for individual guid-
ance and management of the acute and the subacute
whiplash patient. Application of the risk assessment
score may be a valuable alternative to the present WAD
grading system in predicting work disabi lity and pain
and certain psychosocial parameters after neck injury.
Furthermore, a simila r biopsychosocial risk assessment
could be considered in other acute conditions bearing a
risk of long-term development of other chronic dysfunc-
tional pain conditions.
Author affiliations
1
Department of Neurology, The Danish Pain Research Center, Aarhus
University Hospital, Aarhus, Denmark
2
Department of Research, Spine Center of Southern Denmark, Hospital
Lillebaelt, Institute of Regional Health Research, University of Southern
Denmark, Odense M, Denmark
3
Department of Neurophysiology, Aarhus University Hospital, Aarhus,
Denmark
4
Department of Neurology, Aarhus University Hospital, Aalborg Hospital,
Aalborg, Denmark
5
Department of Rheumatology, Copenhagen Spine Center, Glostrup Hospital,
Glostrup, Denmark
Acknowledgements Participants were recruited with the help of the staff at
the emergency units at hospitals in the four former counties of Viborg,
Aarhus, Vejle and Funen during the enrolment period. Statistical consultation
was provided from the Department of Statistics, University of Southern
Denmark on designing the study.
Contributors HK, TJ, TB and FB initially conceived the idea of the study;
further elaboration of the protocol was made by AK and EQ, and all authors
were responsible for the design of the study. Analysis of data was performed
by HK, TJ and AK. HK, TJ, FB, TB, EQ and AK contributed to the
interpretation of results. HK, TJ, TB, FB and AK were involved in the
development of graphs and tables for the manuscript. The main draft of the
manuscript was performed by HK and TJ. Critical revisions were made by AK,
TB and FB. All writers took part in the successive drafts of the manuscript.
Funding Financial support was provided by an unrestricted grant from
The Danish Insurance Association.
Competing interests None.
Ethics approval The Scientific Committee for The Counties of Vejle and
Funen, Project number 20000268, Denmark.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement There are no additional data available.
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