Effect of an education and activation programme on functional limitations and patient-perceived recovery in acute and sub-acute shoulder complaints - a randomised clinical trial.

Abstract

The education and activation programme (EAP) aims at coping with psychosocial determinants to prevent the development of chronic shoulder complaints (SCs). The effect of the EAP on functional limitations and patient-perceived recovery after 6 and 26 weeks is evaluated in a randomised clinical trial.
Patients with SCs present at rest or elicited by movement and lasting no longer than 3 months were allocated at random to either EAP as an addition to usual care (UC), or to UC only. Measurements were taken at baseline and after 6 and 26 weeks and were analysed by means of multilevel analysis for the group effect. EAP was administered by GPs or by an ambulant therapist (CDB). Patients in the UC group were given UC by their own GP.
Multilevel analysis failed to show a significant effect of the EAP on either functional limitations or patient-perceived recovery. Analysis showed coincidentally a relation between catastrophising at baseline and functional limitations.
The EAP has no significant effect on the outcome of SCs after 6 and 26 weeks. The relation between catastrophising at baseline and functional limitations suggests that an intervention focusing specifically on catastrophising may be more successful in reducing functional limitations in the long term. Further research is however needed to evaluate the effect of catastrophising at baseline on the course of SCs.
Current Controlled Trials ISRCTN71777817.

Full text

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BioMed Central
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BMC Musculoskeletal Disorders
Open Access
Research article
Effect of an education and activation programme on functional
limitations and patient-perceived recovery in acute and sub-acute
shoulder complaints – a randomised clinical trial
Camiel De Bruijn*1,2, Rob de Bie1,3, Jacques Geraets1,4, Marielle Goossens1,4,
Wim van den Heuvel1, Geert van der Heijden5, Math Candel6 and Geert-
Jan Dinant2
Address: 1Institute for Rehabilitation Research, PO box 192, 6430 AD, Hoensbroek, The Netherlands, 2Maastricht University, Department of
General Practice and Care and Public Health Research Institute, PO box 616, 6200 MD, Maastricht, The Netherlands, 3Maastricht University,
Department of Epidemiology, PO box 616, 6200 MD, The Netherlands, 4Maastricht University, Department of Medical, Clinical and Experimental
Psychology, PO box 616, 6200 MD, The Netherlands, 5University Medical Centre, Julius Center for Health Sciences and Primary Care, PO box
85500, 3508 GA, Utrecht, The Netherlands and 6Maastricht University, Department of Statistics and Methodology, PO box 616, 6200 MD, The
Netherlands
Email: Camiel De Bruijn* - cdbn@cbs.nl; Rob de Bie - RA.deBie@EPID.unimaas.nl; Jacques Geraets - jacques.geraets@planet.nl;
Marielle Goossens - M.Goossens@DEP.unimaas.nl; Wim van den Heuvel - .vandenheuvel@irv.nl; Geert van der
Heijden - G.vanderHeijden@umcutrecht.nl; Math Candel - Math.Candel@STAT.unimaas.nl; Geert-
Jan Dinant - GeertJan.Dinant@HAG.unimaas.nl
* Corresponding author
Abstract
Background: The education and activation programme (EAP) aims at coping with psychosocial
determinants to prevent the development of chronic shoulder complaints (SCs). The effect of the
EAP on functional limitations and patient-perceived recovery after 6 and 26 weeks is evaluated in
a randomised clinical trial.
Methods: Patients with SCs present at rest or elicited by movement and lasting no longer than 3
months were allocated at random to either EAP as an addition to usual care (UC), or to UC only.
Measurements were taken at baseline and after 6 and 26 weeks and were analysed by means of
multilevel analysis for the group effect. EAP was administered by GPs or by an ambulant therapist
(CDB). Patients in the UC group were given UC by their own GP.
Results: Multilevel analysis failed to show a significant effect of the EAP on either functional
limitations or patient-perceived recovery. Analysis showed coincidentally a relation between
catastrophising at baseline and functional limitations.
Conclusion: The EAP has no significant effect on the outcome of SCs after 6 and 26 weeks. The
relation between catastrophising at baseline and functional limitations suggests that an intervention
focusing specifically on catastrophising may be more successful in reducing functional limitations in
the long term. Further research is however needed to evaluate the effect of catastrophising at
baseline on the course of SCs.
Trial registration: Current Controlled Trials ISRCTN71777817
Published: 15 November 2007
BMC Musculoskeletal Disorders 2007, 8:112doi:10.1186/1471-2474-8-112
Received: 29 March 2007
Accepted: 15 November 2007
This article is available from: http://www.biomedcentral.com/1471-2474/8/112
© 2007 De Bruijn et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Background
Psychological and social factors are known to play a role
in the development and persistence of chronic muscu-
loskeletal diseases [1-3]. Furthermore, previous studies
showed that therapies aimed at coping with psychosocial
determinants are promising interventions to prevent mus-
culoskeletal pain from becoming chronic [4-8]. Up till
now, usual care (UC) in patients with shoulder com-
plaints (SCs) in the Netherlands has mainly focused on
the biomedical determinants mentioned in the clinical
guidelines of the Dutch College of General Practitioners
[9]. Since half of all newly presented episodes of SCs in
general practice last for at least six months, a therapy
aimed at coping with psychosocial determinants may
reduce the proportion of SCs that become chronic [10].
We have therefore developed an education and activation
programme (EAP) aimed at coping with psychosocial
determinants to prevent the development of chronic SCs.
Psychosocial determinants influence cognitions and
behaviours. The EAP attempts to steer these cognitions
and behaviours in the desired direction to avoid the devel-
opment of inadequate cognitions and maladaptive behav-
iours. In this context, cognitions refer to the way patients
think about their SCs and what these complaints mean to
them, in terms of thoughts, beliefs, attitudes and self-effi-
cacy expectations [11], whereas behaviour refers to the
patients' observable actions [12].
Our hypothesis is that in the acute and sub-acute stages of
the SCs, cognitions and behaviours are easily susceptible
to modification, which means that the EAP can be admin-
istered in a brief intervention by specially trained general
practitioners (GPs) or a trained ambulant therapist. A ran-
domised clinical trial was set up to evaluate the effect of
the EAP as an addition to UC, compared to UC alone, on
patient-perceived recovery and changes in functional lim-
itations of activities of daily living after 6 weeks and 26
weeks [13]. This paper presents the results of the ran-
domised clinical trial as regards functional limitations
and patient-perceived recovery after 6 and 26 weeks. The
trial is part of a national study on shoulder complaints in
general practice, which includes a prognostic cohort study
with three randomised clinical trials in subcohorts. This
study is funded by The Netherlands Organization for
Health Research and Development (grant number 940-
31-085).
Methods
Study design
In our randomised clinical trial, patients were allocated at
random to either EAP as an addition to UC, or to UC only.
Measurements were taken at baseline and after 6 and 26
weeks by a self administered questionnaire. The 6 and 26
weeks questionnaires were sent and returned by mail. The
6 weeks measurement provided information on the
immediate effect of the EAP as the EAP had to be admin-
istered within the six week period after the baseline meas-
urement. The 26 weeks
information on the long term effect of the EAP. EAP was
administered by GPs or by an ambulant therapist (CDB)
if no EAP-trained GP was available near a patient's home.
All GPs who provided EAP attended a three-hour training
session, in which the EAP was introduced and role-plays
were used to train the proper administration of EAP. The
GPs received a training manual during this session in
which the principles of the EAP were summarized.
Patients in the UC group were given UC by their own GP,
unless their GP had attended the EAP training. In that
case, UC was administered by a colleague from the same
GP group practice, to avoid contamination. The design of
this study has been described in detail in a previous pub-
lication [13]. The Medical Ethics Committee of the Insti-
tute for Rehabilitations Research in association with
Rehabilitation Foundation Limburg has approved this
randomised clinical trial.
measurement provided
Patients and procedure
Eligible patients had consulted their own GP or
responded to advertisements in local newspapers calling
on people with a new and untreated episode of SCs that
had lasted less than three months and produced com-
plaints at rest or complaints elicited by shoulder move-
ment. Patients were included if they were older than 18
years and living in the south of the Netherlands. Addi-
tional inclusion and exclusion criteria are given in table 1.
Table 1: Inclusion and exclusion criteria
Inclusion criteria Exclusion criteria
• SC present at rest or elicited by movement
• SC episode lasting no longer than 3 months
• First episode of SC for 12 months
• Newly presented episode (no prior consultations or treatments for this
episode in the previous three months)
• Older than 18 years
• Living in the south of the Netherlands
• Prior fractures and/or surgery of the shoulder
• (Suspected) referred pain from internal organs
• SCs with a confirmed extrinsic cause
• Inability to complete a questionnaire independently
• Presence of dementia or other severe psychiatric abnormalities

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The patient recruitment procedure in the consultation
room was designed to minimize the time needed by the
GP, since lack of time is often mentioned as one of the
main barriers when recruiting patients in general practice
[14]. GPs pointed out the existence of the EAP trial to
patients with newly presented SCs, checked the inclusion
and exclusion criteria and forwarded the patients' per-
sonal data by fax to the research centre. The patients had
to give written permission for their personal data to be
forwarded to the research centre. The GPs were advised to
refer patients to the research centre for further informa-
tion about the EAP trial. Patients responding to the adver-
tisements were first screened by telephone for inclusion
and exclusion criteria. Patients meeting the inclusion cri-
teria were subsequently visited by an independent GP
involved in the EAP trial (EAP-GP). This EAP-GP provided
the patients with a regular consultation for SCs. Personal
data of eligible patients were forwarded to the research
centre. In both recruitment strategies, the research assist-
ant contacted patients within 2 weeks and took care of
final inclusion and randomisation. The baseline question-
naire was handed out and after completion returned to
the research assistant.
Blocked and concealed randomisation with blocks of 4
patients was used to allocate patients to either the EAP
group or the UC group. An independent researcher used a
computer-generated random sequence table to randomise
the patients in each block. The seals of the prepared, num-
bered, opaque, sealed envelopes containing the treatment
group were broken by the research assistant after eligibil-
ity had been verified and the patient had given written
informed consent.
Blinding
Neither the patients nor the GPs, nor the trained ambu-
lant therapist, could be blinded for the allocated treat-
ment. The ambulant therapist was also the researcher
coordinating the randomised clinical trial and conducting
the data analysis, but he was blinded for treatment alloca-
tion during the data analysis. The allocation code was kept
by an independent researcher (JG) and was revealed only
after data analysis had been completed.
Interventions
The focus of EAP is to maintain or induce the proper cog-
nitions by education and to stimulate adequate behaviour
by means of advice on activities of daily living, using prin-
ciples of operant conditioning (11). The programme con-
sists of an educational and an activation part.
The educational part of the EAP consists of tailored infor-
mation intended to take away the worries and answer
questions patient may have regarding their SCs. Special
care is taken to structure the information and advice that
patients receive from other individuals in their social and
health care environment. The information and advice are
tailored to the patients' thoughts. Preconceptions on SCs
are identified and altered if they are incorrect or reinforced
if they are correct. The final aim of the educational part of
the EAP is to provide patients with a realistic idea of their
prognosis and the effect of treatment.
The activation part aims to assist patients in the continua-
tion or resumption of activities affected by the SCs,
despite the pain. The adverse effects of inactivity are dis-
cussed with the patients and activities that patients indi-
cate to be affected by the SCs are closely monitored during
the subsequent consultations. Schedules are set for the
resumption or gradual increase of these activities, using a
time-contingent approach, which means that the resump-
tion or increase of activities occurs irrespective of pain
experience but according to preset goals in time.
The EAP consists of a minimum of two sessions and a
maximum of six follow-up sessions over a period of six
weeks. Each session can last up to 20 minutes.
UC was administered according to the clinical guidelines
of the Dutch College of General Practitioners [9].
Outcome Measures
The first primary outcome measure, assessed at 6 and 26
weeks after randomisation, was patient-perceived recov-
ery (PPR) [10]. Patients were considered recovered when
they reported to be 'much improved' or 'fully recovered',
on a 7-point ordinal scale, six weeks after randomisation.
The second primary outcome measure was a change in
functional limitations of activities of daily living. This var-
iable was assessed by the 16-item shoulder disability
questionnaire (SDQ)[15], with a standardised scoring
range of 0 to 100. A lower score on this questionnaire
implies lower levels of functional limitations.
Several psychosocial variables were assessed at baseline.
Anxiety, depression, somatisation and distress were
assessed using the four-dimensional complaint list [16].
Catastrophising and coping were assessed by 6-level sub-
scales of the Pain Coping and Cognition List (1: com-
pletely disagree; 6: completely agree) [17]. Mean subscale
scores of 1 were classified as 'very low' (code = 0), scores
between 2 and 6 were classified as elevated (code = 1)
[17]. Other specific disease variables recorded at baseline
were pain intensity, measured on a 10-point visual ana-
logue scale; onset (quick or gradual); affected shoulder
and having had prior episodes of SCs lasting at least 1
week.

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Sample size
About half of all newly presented episodes of SC in gen-
eral practice are reported to last for at least six months. A
number needed to treat of 4.5 after 26 weeks is considered
clinically relevant. This implies an absolute reduction of
22% of the proportion of patients with SC after 26 weeks.
With a two-sided alpha of 0.05 and a statistical power (1-
β) of 0.80, 82 patients per treatment group were needed
to detect a difference in favour of EAP compared to UC
after 26 weeks.
Data analysis
The baseline variables of the treatment groups were com-
pared using chi-square tests and an independent samples
t-test. Significant differences in baseline variables were
considered to be potential confounders. The statistical
data analysis was carried out according to the 'intention-
to-treat' principle.
Patients attending the same GP cannot be assumed to be
fully independent. Similarly, different observations for
the same patient with SCs cannot be assumed to be inde-
pendent either. Multilevel analysis was used to address
this dependency due to clustering of data. The effect of
treatment group (EAP group = 1; UC group = 0) was ana-
lyzed by means of linear multilevel analysis if SDQ was
the outcome variable and logistic multilevel analysis if
patient-perceived recovery was the outcome variable.
Three levels of variance were distinguished: GPs, subjects
and measurements.
In the linear multilevel analysis, baseline SDQ scores were
entered into the model to adjust for differences at base-
line. Since none of the patients were recovered at baseline,
no adjustment was needed for patient-perceived recovery
at baseline in the logistic multilevel analysis. Time of
measuring was represented in the model by two dummy
variables for the measurements at 6 and 26 weeks. Poten-
tial confounders were also entered into the linear and
logistic model as independent variables. Finally, the inter-
action effect between the treatment group and the time of
measuring was also included in the model.
The multilevel analyses resulted in estimates (and stand-
ard errors) of the fixed and random effects. Likelihood
ratio (LR) test statistics were used to determine whether
the estimates were statistically significant (p < 0.05) in the
linear multilevel analyses. Wald chi-square tests were used
to determine the statistical significance of the estimates in
the logistic multilevel analyses. Estimates that did not
reach the required level of significance were excluded
from the model in a top-down procedure, except for the
intervention variable, leaving out the least significant esti-
mates first. For the logistic multilevel analysis, these esti-
mates were converted to odds ratios with their 95%
confidence intervals. All multilevel analyses were per-
formed with MLwiN (version 1.10) [18,19].
Results
Patients
GPs referred a total of 133 patients for participation in the
EAP trial, 74 of whom were actually included in the trial.
In total, 64 patients responded to the advertisements. Of
these, 44 met the selection criteria, as ascertained by a tel-
ephone interview. The subsequent visit by the EAP-GP
resulted in the final inclusion of 37 patients. A total of 111
patients were thus eventually recruited to participate in
the study (figure 1). Three patients dropped out after ran-
domisation without receiving any treatment, and were
therefore excluded from further analysis. After 6 weeks,
complete data was available for 40 patients (77%) in the
UC group and 48 patients (86%) in the EAP group. After
26 weeks, complete data was available for 35 patients
(67%) in the UC group and 44 (79%) patients in the EAP
group.
Baseline variables
Table 2 shows that there were no statistically significant
differences between the two treatment groups at baseline
for any of the variables except catastrophising. The effect
of baseline differences in catastrophising was evaluated by
entering this variable into the multilevel analysis models.
Multilevel analyses
Estimates with their standard error and levels of signifi-
cance are presented in table 3 for the linear multilevel
analyses of the SDQ scores. The interaction terms between
the two dummy variables and the group variable did not
reach significance and were excluded from the final model
in the top-down procedure. This implies that the potential
effect of treatment group was similar at both post meas-
urements. In the final model, treatment group turned out
to have no effect at either of the measurements. Catastro-
phising at baseline and baseline SDQ scores were signifi-
cantly and positively related to SDQ scores at both post
measurements. Time dummy 1 and time dummy 2 were
significantly and negatively related to SDQ scores, sug-
gesting that SDQ score, representing the level of func-
tional limitations, decreases as time progresses.
Estimates with their standard errors and levels of signifi-
cance for the logistic multilevel analyses of the PPR are
presented in table 4. Data were interpreted by converting
estimates to odds ratios (ORs). The top-down procedure
resulted in the exclusion of the interaction terms from the
logistic model. This implies that the potential effect of
treatment group was similar for both post measurements.
In the final analysis model, the treatment group had a
non-significant (p = 0.1784) effect on patient-perceived
recovery. A significant effect was found for time dummy 1

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Flow chart
Figure 1
Flow chart.
Table 2: Baseline variables
UCEAP p-value
Number
Demographic variables
Age (years) (SD)
Gender ? (%)
Specific disease variables
Pain intensity T0 (mean + SD)
Onset (quick) (%)
Affected shoulder (Left/right/both) (%)
Prior episodes of SCs lasting at least 1 week (% yes)
Outcome variable
SDQ score at baseline (mean and SD)
Psychosocial variables
Catastrophising (% very low)
Coping (% very low)
Distress categories (low-medium-high; %)
Depression categories (low-medium-high; %)
Anxiety categories (low-medium-high; %)
Somatisation (low-medium-high; %)
5256
49.9 (11.7)
44
48.4 (16.2)
36
0.572
0.366
5.2 (2.3)
44
42-52-6
42
5.3 (2.2)
54
41-57-2
49
0.887
0.286
0.538
0.482
60.8 (24.1) 67.1 (24.0)0.175
49
12
27
8
0.022
0.463
0.815
0.357
-
0.231
79-17-4
94-2-4
100-0-0
85-11-4
80-18-2
91-7-2
100-0-0
82-18-0

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and time dummy 2, indicating a significant effect on PPR
of the time elapsed since baseline. Baseline levels of cata-
strophising did not have a significant effect on the PPR
and were excluded from the final analysis model.
Discussion
Multilevel analysis using either Shoulder Disability Ques-
tionnaire (SDQ) scores or PPR as the outcome variable
failed to show a significant effect of the EAP. Baseline lev-
els of catastrophising were significantly and positively
related to functional limitations. Patient-perceived recov-
ery (PPR), on the other hand, was not significantly related
to baseline levels of catastrophising. A significant effect of
time was found for both outcome variables.
The positive and significant correlation between func-
tional limitations and elevated levels of catastrophising at
baseline suggests the existence of a relation between the
two. Such a relation is plausible, as catastrophising refers
to 'an exaggerated negative orientation toward pain stim-
uli and pain experience' [20-22]. This may cause patients
with SCs to be more reluctant to use their shoulder, result-
ing in increased functional limitations.
In view of this, it is remarkable that no relation was found
between catastrophising and patient-perceived recovery,
since negative orientation is expected to affect the percep-
tion of the SCs as well. Such a relation between catastro-
phising and the chronic pain experience has indeed been
found in patients with low back pain [23-27]. Further-
more, Kuijpers et al. also found an association between
catastrophising at baseline and PPR after 6 weeks in
patients with SCs. A possible explanation for the absence
of a relation in our analysis may have been the dichoto-
mous nature of the outcome measure making it difficult
to detect a relation between catastrophising and patient-
perceived recovery.
The relation between catastrophising and functional limi-
tations at baseline and the absence of a relation with
patient-perceived recovery raises some questions. Why
does the EAP have no effect on functional limitations,
even though one of its aims is to change catastrophising
cognitions? On the other hand, the absence of a relation
with patient-perceived recovery raises the question
whether it is worthwhile to intervene on catastrophising
cognitions if no relation is found between the two
although it is also possible that the absence of such a rela-
tion can be attributed to the dichotomous nature of the
outcome measure.
At the start of this study, little was known about the spe-
cific effect of psychosocial determinants in SCs, although
interventions aiming to modify these determinants, such
Table 4: Results of the logistic multilevel analysis of patient-perceived recovery
VariableEstimate (SE) OR 95% CIp-value
Fixed parameter
Treatment group
Time dummy 1 (6 weeks)2
Time dummy 2 (26 weeks)3
0.85(0.63)
1.24(0.45)
2.60(0.49)
2.34
3.46
13.46
[0.68;8.00]
[1.43;8.33]
[5.16;35.16]
0.17841
0.00561
0.00001
1 Based on the Wald statistic
2 This variable has the code 1 for 6 weeks and 0 otherwise
3 This variable has the code 1 for 26 weeks and 0 otherwise
Table 3: Results of the linear multilevel analysis of SDQ
VariableEstimate (SE)p-value
Fixed parameter
Treatment group
Time dummy 1 (6 weeks)1
Time dummy 2 (26 weeks)3
Catastrophising at baseline
SDQ score at baseline
Random effects
Variance at patient level
? Time dummy1
? Time dummy 2
3.44(4.98)
-8.18(3.24)
-17.26(4.03)
6.84(5.10)
0.53(0.11)
0.4916
0.01162
0.00002
0.0000
0.0000
819.03(133.67)
1227.20(205.03)
0.00002
0.00002
1 This variable has the code 1 for 6 weeks and 0 otherwise
2 Based on the Wald statistic
3 This variable has the code 1 for 26 weeks and 0 otherwise

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as cognitive behavioural programs were considered to be
promising for musculoskeletal pain in general [4-8]. We
developed the EAP to fill a gap in UC, which focuses
mainly on biomedical determinants. The EAP uses tech-
niques used in cognitive behavioural therapy that were
expected to benefit patients in the early stages of SCs. Fur-
thermore, GPs had to be able to apply these techniques
after a brief training whereas cognitive behavioural pro-
grams are usually administered by specialized therapists.
The lack of information on specific psychosocial determi-
nants of SCs made us develop a generic intervention
addressing several psychosocial determinants, of which
catastrophising cognitions is only one. This generic nature
of the EAP may be the reason that we found no effect on
outcome. Although this study shows that catastrophising
at baseline is related to one of the outcome measures,
namely functional limitations, catastrophising cognitions
are not the main focus of the EAP. Another reason for the
absence of an effect of the EAP may be that other,
unknown, determinants are more closely related to SCs.
This view is supported by the absence of a relation
between catastrophising at baseline and patient-perceived
recovery, suggesting that the relation between catastro-
phising and outcome is not as straightforward as
expected.
It should be noted that the relation between catastrophis-
ing at baseline and functional limitations was a coinci-
dental finding of this study. Baseline levels of
catastrophising were initially entered into the multilevel
models to adjust for baseline differences between study
groups. A study by van der Windt et al. showed that higher
levels of catastrophising in patients with longer symptom
duration are significantly associated with persistent symp-
toms [28]. Further study is needed to evaluate the effect of
catastrophising in SCs and the possibilities of interven-
tions focusing on catastrophising.
The significant effect of time on outcome suggests that SCs
are likely to improve over time regardless of the interven-
tion. This positive effect of time is found in other studies
as well [10,29-31]. Identifying patients with this favoura-
ble natural course in the early stages of SCs appears to be
difficult [32]. Otherwise, the effectiveness of any interven-
tion could be improved by focussing on the patients at
risk. Further study is needed to identify factors predicting
a favourable natural course in the early stages.
Analysis of videotaped consultations showed that not all
key features of the EAP were applied by the trained GPs
[33]. Furthermore, GPs administering UC were already
including some key features exclusively attributed to the
EAP in their UC. This may have reduced the contrast
between the treatment groups.
Ours appears to be the first study addressing psychosocial
determinants in patients with acute and sub-acute SCs in
general practice. A recent study evaluating a similar inter-
vention in patients with low back pain in general practice
also found no effect [34].
Outcome measures were collected using self reported
questionnaires. Both patient perceived recovery and func-
tional limitations may thus be influenced by the state of
mind of the patient reporting the outcome. From this
point of view, outcome measures reflect the patient's sub-
jective perspective whereas an objective measure would be
unbiased by the patient's state of mind. We preferred a
subjective outcome over an objective outcome as we
wanted to evaluate the effectiveness of the intervention
from the patient's perspective.
The effect of the EAP on total costs related to SCs is evalu-
ated using bootstrap analysis [35]. This analysis showed
that the EAP is more effective but at higher costs. Furuther-
more, healthcare utilisation showed no difference
between the study groups. It should be noted that a boot-
strap analysis is specifically designed to evaluate the cost-
effectiveness of an intervention. The multilevel analysis
presented in this paper is able to determine the isolated
effect of the EAP.
Recruitment by GPs fell short of our expectations. There-
fore we opted for an alternative strategy using advertise-
ments. This introduces the risk of selection bias. However,
a comparison of baseline values (not presented) showed
no differences between the recruitment methods. Even
more, entering recruitment method as a variable in the
multilevel analysis showed no significant effect of recruit-
ment method on outcome (not presented in this paper).
It appeared that GPs recruiting patients were less accurate
in checking the inclusion and exclusion criteria. This
resulted in a higher exclusion rate of patients referred for
participation in the trial by GPs.
It may be questioned whether a brief training is sufficient
to enable GPs to administer the EAP as prescribed. Our
hypothesis was that patients' cognitions and behaviours
in the acute and sub-acute stages of the SCs are susceptible
to modification. We may have underestimated, however,
that cognitions and behaviours by the GPs towards SCs
were less susceptible to modification, and that the GPs
might require a more intense training to become thor-
oughly acquainted with the key features of the EAP. This
may have affected the quality of the EAP administered by
the GPs.
Based on our sample size calculation, we needed 82
patients per treatment group. However, patient recruit-
ment fell short of our expectations. Eventually, 56 patients

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were included in the EAP group and 52 patients were
included in the UC group. This resulted in a reduction of
the power of this study. A post-hoc power calculation
indicated a statistical power of 0.63, compared to the
intended power of 0.80. This power reduction increases
the risk of a 'false negative' finding in this study.
Although complete data was available for 67% of the
patients in the UC group and 79% of the patients in the
EAP group, multilevel analysis made it possible to use all
data available of the 52 patients in the UC group and 56
patients in the EAP group. The difference in available
complete data between groups may be influenced by the
fact that patients were not blinded. It is likely that patients
in the UC group were less inclined to complete participa-
tion in the study after being allocated to UC.
Conclusion
Multilevel analysis shows that the EAP has no significant
effect on the outcome of SCs. A coincidental finding of
this study was the relation between catastrophising at
baseline and functional limitations. This relation suggests
that an intervention focusing specifically on catastrophis-
ing may be more successful in reducing functional limita-
tions in the long term. In contrast, the EAP addresses
catastrophising as one of several psychosocial determi-
nants of SCs. The effect of an intervention focusing on cat-
astrophising may be improved by selecting patients with
elevated levels of catastrophising at baseline. Further
research is needed to evaluate the effect of catastrophising
at baseline on the course of SCs.
Competing interests
The author(s) declare that they have no competing inter-
ests.
Authors' contributions
CDB drafted the manuscript, participated in the design of
the study and performed the statistical analysis. RDB and
GJD participated in the coordination of the study and
helped to draft the manuscript. JG and MG participated in
the coordination of the study and the design of the ques-
tionnaires. WVDH critically reviewed the methods used in
this study and helped to draft the manuscript. GVDH con-
ceived of the study and participated in the design of the
study and reviewed the manuscript. MC participated in
the statistical analysis. All authors read and approved the
final manuscript.
Acknowledgements
The EAP-trial is part of the Dutch Shoulder Disability Study, a comprehen-
sive prognostic cohort study on SCs, with randomised clinical trials in sub-
cohorts. The Dutch Shoulder Disability Study is funded by the Netherlands
Organisation for Scientific Research (NWO, grant number 904-65-901).
References
1.Linton S: A Systematic Review of Psychological Risk Factors
for Back and Neck Pain. Spine 2000, 25:1148-1156.
2. Turk DC: The Role of Demographic and Psychosocial Factors
in Transition from Acute to Chronic Pain. Volume 8. Edited by:
Jensen TS, Turner JA, Z. WH. IASP Press; 1997:185-213.
3. Weiser S, Cedraschi C: Psychosocial Issues In The Prevention
Of Chronic Low Back Pain - A Literature Review. Bailliere's
Clinical Rheumatology 1992, 6(3):657-684.
4. Linton SJ: Prevention With Special Reference To Chronic
Musculoskeletal Disorders. In Psychosocial Factors In Pain Edited
by: Gatchel RJ, Turk DC. New York , Guilford Publications;
1999:374-389.
5.Mitchell RI, Carmen GM: Results of a multicenter trial using an
intensive active exercise program for the treatment of acute
soft tissue and back injuries. Spine 1990, 15(6):514-521.
6.Lindstrom I, Ohlund C, Eek C, Wallin L, Peterson LE, Fordyce WE,
Nachemson AL: The effect of graded activity on patients with
subacute low back pain: a randomized prospective clinical
study with an operant-conditioning behavioral approach.
Phys Ther 1992, 72(4):279-90; discussion 291-3.
7. Haig AJ, Linton P, McIntosh M, Moneta L, Mead PB: Aggressive
early medical management by a specialist in physical medi-
cine and rehabilitation: effect on lost time due to injuries in
hospital employees. J Occup Med 1990, 32(3):241-244.
8.Malmivaara A, Hakkinen U, Aro T, Heinrichs ML, Koskenniemi L,
Kuosma E, Lappi S, Paloheimo R, Servo C, Vaaranen V, et al.: The
treatment of acute low back pain--bed rest, exercises, or
ordinary activity? N Engl J Med 1995, 332(6):351-355.
9. Winters JC, Jongh ACD, D. A. W. M. van der Windt, Jonquiere M,
Winter AFD, G. J. M. G. van der Heijden, Sobel JS, Goudswaard AN:
NHG-Standaard Schouderklachten. Huisarts en Wetenschap
1999, 42(5):222-231.
10.Windt DA, Koes BW, Boeke AJ, Deville W, Jong BAD, Bouter LM:
Shoulder disorders in general practice: prognostic indicators
of outcome. Br J Gen Pract 1996, 46(410):519-523.
11.Wit R, Dam F, Litjens M, H. HAS: Assessment of Pain Cognitions
in Cancer Patients with Chronic Pain. Journal of Pain and Symp-
tom Management 2001, 22(5):911-924.
12.Fordyce WE: Behavioral Methods For Chronic Pain And Ill-
ness. Saint Louis , C. V. Mosby Company; 1976.
13. Bruijn CD, de Bie R, Geraets J, Goossens M, Koke A, van den Heuvel
W, van der Heijden G, Dinant GJ: Evaluation of an education and
activation programme to prevent chronic shoulder com-
plaints: design of an RCT [ISRCTN71777817]. BMC Fam Pract
2005, 6(1):7.
14.Prout H, Butler C, Kinnersley P, Robling M, Hood K, Tudor-Jones R:
A qualitative evaluation of implementing a randomized con-
trolled trial in general practice. Fam Pract 2003, 20(6):675-681.
15.van der Heijden GJMG, Leffers P, Bouter LM: Development And
Responsiveness Of The Shoulder Disability Questionnaire.
Journal of Clinical Epidemiology 1999.
16.Terluin B: De Vierdimensionale Klachtenlijst (4DKL) In De
Huisartspraktijk. De Psycholoog 1998:18-24.
17.Berg SGMS, Vlaeyen JWS, Kuile MM, Spinhoven P, Breukelen G, Kole-
Snijders AMJ: Pijn Coping en Cognitie Lijst. 1999.
18. Rasbash J, Browne W, Goldstein H, Yang M, Plewis I, Healy M, Wood-
house G, Draper D, Langford I, Lewis T: A user's guide to MLwiN
(Second Edition). London , Institute of Education University of
London; 2000.
19.Rasbash J, Browne W, Healy M, Cameron B, Charlton C: MLwiN.
1.10.0007 edition. London , Multilevel Models Project Institute of Edu-
cation; 2001.
20.Chaves JF, Brown JM: Spontaneous cognitive strategies for the
control of clinical pain and stress. J Behav Med 1987,
10(3):263-276.
21.Geisser ME, Robinson ME, Keefe FJ, Weiner ML: Catastrophizing,
depression and the sensory, affective and evaluative aspects
of chronic pain. Pain 1994, 59(1):79-83.
22.Sullivan MJL, Bishop SR, Pivik J: The pain catastrophizing scale:
development and validation. Psychol Assess 1995, 7:524-532.
23. Crombez G, Vlaeyen JWS, Heuts PHTG, Lysens R: Pain-Related
Fear Is More Disabling Than Pain Itself: Evidence On The
Role Of Pain-Related Fear In Chronic Back Pain Disability.
Pain 1999, 80:329-339.

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24.Crombez G, Vervaet L, Lysens R, Baeyens F, Eelen P: Avoidance
and confrontation of painful, back-straining movements in
chronic back pain patients. Behav Modif 1998, 22(1):62-77.
Main CJ, Waddell G: A comparison of cognitive measures in
low back pain: statistical structure and clinical validity at ini-
tial assessment. Pain 1991, 46(3):287-298.
Vlaeyen JWS, Seelen HAM, Peters M, Jong P, Aretz E, Beisiegel E,
Weber WEJ: Fear Of Movement/(Re)Injury And Muscular
Reactivity In Chronic Low Back Pain Patients: An Experi-
mental Investigation. Pain 1999, 82:297-304.
Vlaeyen JWS, Kole-Snijders AMJ, Boeren RGB, Eek H: Fear Of
Movement/(Re)Injury In Chronic Low Back Pain And Its
Relation To Behavioral Performance. Pain 1995, 62:363-372.
van der Windt DA, Kuijpers T, Jellema P, van der Heijden GJ, Bouter
LM: Do psychological factors predict outcome in both low
back pain and shoulder pain? Ann Rheum Dis 2006.
Winters JC, Jorritsma W, Groenier KH, Sobel JS, Jong BM, Arendzen
HJ: Treatment Of Shoulder Complaints In General Practice:
Long Term Results Of A Randomised, Single Blind Study
Comparing Physiotherapy, Manipulation, And Corticoster-
oid Injection. British Medical Journal 1999, 318:1395-1396.
Geraets JJ, Goossens ME, de Groot IJ, de Bruijn CP, de Bie RA, Dinant
GJ, van der Heijden G, van den Heuvel WJ: Effectiveness of a
graded exercise therapy program for patients with chronic
shoulder complaints. Aust J Physiother 2005, 51(2):87-94.
Kuijpers T, van der Windt DA, van der Heijden GJ, Bouter LM: Sys-
tematic review of prognostic cohort studies on shoulder dis-
orders. Pain 2004, 109(3):420-431.
Kuijpers T, van der Windt DA, Boeke AJ, Twisk JW, Vergouwe Y,
Bouter LM, van der Heijden GJ: Clinical prediction rules for the
prognosis of shoulder pain in general practice. Pain 2006,
120(3):276-285.
De Bruijn C, de Bie R, Geraets J, Goossens M, Koke A, van den Heu-
vel W, Dinant GJ: General practitioners apply the usual care
for shoulder complaints better than expected--analysis of
videotaped consultations. BMC family practice 2007, 8:13.
Jellema P, van der Windt DA, van der Horst HE, Twisk JW, Stalman
WA, Bouter LM: Should treatment of (sub)acute low back pain
be aimed at psychosocial prognostic factors? Cluster ran-
domised clinical trial in general practice. Bmj 2005,
331(7508):84.
De Bruijn C, Goossens M, de Bie R, Ament A, Geraets J, Dinant GJ:
Cost-effectiveness of an education and activation program
for patients with acute and subacute shoulder complaints
compared to usual care. International journal of technology assess-
ment in health care 2007, 23(1):80-88.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
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