ExStroke Pilot Trial of the effect of repeated instructions to improve physical activity after ischaemic stroke: a multinational randomised controlled clinical trial
BMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b2810 (Published 22 July 2009) Cite this as: BMJ 2009;339:b2810
All rapid responses
In addition to the comments by Mutrie about the intervention design,
the study by Boysen showing no effect on physical activity levels after
stroke was weakened by use of a self report outcome measure. The Physical
Activity Scale for the Elderly (PASE) is of only low validity when
compared to objective measures of physical activity.
In the baseline data of the Hunter Community Study, 669 participants
have completed both the PASE questionnaire and worn a step counter for a
week. The correlation between these two measures of activity was only
slight; r=0.37 for women and 0.30 for men. More alarmingly, PASE had very
limited power to predict health markers such as BMI, HDL or fibrinogen
level. Out of 12 candidate markers the PASE identified a relationship with
only 3 while step count demonstrated a statistically significant
relationship with ten of the twelve markers.(1)
Although scales such as PASE have been "validated" they give only a
crude indication of physical activity levels and should be avoided in
scientific research. Boysen et al could easily have used step counts as
the outcome measure and may well have found a significant result.
reference
Pedometer counts superior to physical activity scale for identifying
health markers in older adults.
B. Ewald, M McEvoy, J Attia British Journal of Sports Medicine 2008 Jul
2008; doi:10.1136/bjsm.2008.048827
Competing interests:
None declared
Competing interests: No competing interests
We appreciate the comments made by Nanette Mutrie and coworkers to
our
paper on ExStroke Pilot Trial(1). They suggest that we should have
followed
published guidelines, however, the articles they refer to were published
long
after we started our trial in 2003. We agree that complex interventions
like
promotion of physical activity requires good planning and person centred
consultations. In the ExStroke trial counselling was given in a dialogue
between the participant and the physiotherapist, and as far as possible it
was
the same person who met the participant at the follow up sessions. In our
view it will be difficult to improve on this aspect of the intervention.
It might,
however, have been possible to make higher demands on length of time the
participant spent on physical activity.
Our study was powered to detect a difference of 20 PASE (Physical Activity
Scale for the Elderly) points between the intervention and control group.
Such
a difference might be obtained by many different forms of physical
activity. It
did not seem unrealistic, as we in a previous study(2) found that age-
matched community controls had a mean PASE score of 119 +/- 69 points as
compared to stroke survivors 76 +/- 46 points. The 2 hours 3 times weekly
of walking was just given as an example. The suggested activity increase
is
more than the recommended 5 x 30 minutes for the general population.
However, for persons who have just survived a mild stroke, it would seem
realistic to spend more time to promote health.
Our expectations were not fulfilled; we therefore suggest that group
training
of stroke patients of duration of 1 to 2 years should be explored. If
successful, such training might be given in community centres as suggested
by Gillian Mead in her editorial(3).
1. Boysen G, Krarup L-H, Zeng X, Oskedra A, Korv J, Andersen G, et
al.
ExStroke Pilot Trial of the effect of repeated instructions to improve
physical
activity after ischaemic stroke: a multinational randomised controlled
clinical
trial. BMJ. 2009 July 22, 2009;339(jul20_3):b2810-.
2. Krarup LH, Truelsen T, Pedersen A, Lerke H, Lindahl M, Hansen L,
et al.
Level of Physical Activity in the Week Preceding an Ischemic Stroke.
Cerebrovascular Diseases. 2007;24(2-
3):296-300.
3. Mead G. Exercise after stroke. BMJ. 2009 July 28,
2009;339(jul28_1):b2795-.
Competing interests:
None declared
Competing interests: No competing interests
The research of Boysen and colleagues revealed that counselling and
repeated encouragement to increase physical activity to patients after
mild stroke failed to have the desired effect.
In this trial the intervention mostly consisted of repeated encouragement
and verbal instructions of training programmes. However physical activity
is the part of patients lifestyle which has both medical and social
aspects. The study was mostly concentrating on delivering medical part of
physical activity which cannot be sometimes achieved in the presence of
social barriers (for example difficult approach to sport centres or
swimming pools, expensive parking facilities, the lack of walking routes).
The authors emphasized that the study proved the verbal encouragement to
be an ineffective tool to motivate patients. Nevertheless the counselling
could have been redesigned in favour to target the social sides of
physical training, such as including social workers into counselling
groups, remodelling questionnaires and approach during consultations, to
gain the proper effectiveness.
Competing interests:
None declared
Competing interests: No competing interests
In last week's BMJ, Dr.Greenberg reported on the consequences of
inappropriate use of citations, when papers expressing a contrary opinion
were simply ignored.
This week, Greenberg's findings seem to have been repeated (at least
in part)by Boysen et al who discussed the effects of physical activity
after ischaemic stroke without reference to the many reports concerning
the role of blood viscosity in the pathogenesis of stroke, or the reports
which show that regular, low intensity physical activity lowers blood
viscosity. Searches in PubMed for "Stroke and blood viscosity" produced
518 titles; for "Physical activity and blood viscosity" produced 116
titles.
In 1986 Woods and Kee published an article titled,
"Hemorheology of the cerebral circulation in stroke," and cited 59
publications, so the role of blood viscosity in stroke is not a new
concept.
What the Boysen et al report seems to indicate is the consequence of
using a treatment modality without recognition of an appropriate
pathophysiology of the condition being treated. Because the aging process
is accompanied by an increase in blood viscosity it is not surprising that
most strokes occur in the elderly, particularly those who are inactive and
are smokers. Inactivity and smoking increase blood viscosity. If it is
not possible to maintain a suitable level of physical activity, then other
ways of reducing blood viscosity should be used. A diet low in fat and
meat and rich in fruit and vegetables would be helpful. As fish oil has
been shown to improve red cell deformabiity, 6 grams daily of fish oil
could be beneficial.
As there are reports which show that in both the pre-stroke and post-
stroke periods, blood viscosity is increased, it is clear that the
management of stroke requires that the effects of hyperviscous blood need
to be addressed, and regular, low intensity physical activity is only one
of several possible treatments.
Competing interests:
None declared
Competing interests: No competing interests
The article from Boysen, et al do not show any benefit of exercise
for stroke survivors. The exercise training is proven to improve
cardiovascular fitness and health. has been well established in the
general population. The role of training in persons with stroke remained
unclear. Stroke rehabilitation programs emphasize functional training as a
means to help the individual gain. Training in the performance of mobility
with attempts to improve muscle strength and coordination. Post stroke
fatigue and depression can be a significant barrier for effective exercise
program. The exercise program should be individual, and depends on the pre
-exercise functional status and co-morbidities.
Competing interests:
None declared
Competing interests: No competing interests
Given the lack of research into encouraging exercise after stroke, we
welcome Boysen and colleagues research paper (Boysen, et al., 2009). In
her editorial Gillian Mead (Mead, 2009) set the context and posed some of
the challenges for research in this area. However we feel opportunities
have been missed in conducting this pilot trial and therefore
inappropriate conclusions may been drawn.
We were surprised that the authors do not seem to have adopted
published guidelines on the topic of developing and evaluating complex
interventions. If this framework had been adopted, (Campbell, et al.,
2000; Craig, et al., 2008) we might have expected modelling of active
ingredients of the intervention (given that it was a pilot study) and
testing the feasibility of the approach. In our own work, we have
modelled, tested and shown success with a physical consultation approach
for the general population (Baker, et al., 2008), for people with Type 2
Diabetes (A. Kirk, Mutrie, MacIntyre, & Fisher, 2003), and in cardiac
rehabilitation (Hughes, Mutrie, & MacIntyre, 2007). Our approach to
consultation is theory driven (Kahn, et al., 2002) and person centred
(Rollnick, et al., 2005), but does not need to be any more intensive or
take more time (~30 minutes) than delivery of repeated verbal
instructions. Each consultation takes a guided approach, asks about past
and current physical activity levels, engages the patient in thinking
about their pros and cons for a change in activity levels, sets realistic
graded incremental goals, encourages the individual to consider social
support for their behaviour change, considers how to enhance self
efficacy for physical activity, and suggests relapse prevention
techniques (A Kirk & Mutrie, 2007).
Our reading of this study suggests a short term beneficial trend in
PASE scores (Table 2, Figure 2), but statistical significance was not
achieved. The study was powered to detect a minimal relevant mean
difference of 20 PASE points between the intervention and the control
groups, corresponding to an increase of physical activity such as walking
outside the home for two hours three times a week. It seems surprising
this was considered a ‘realistic goal’ given this level of activity is
more than twice the recommendation for the general population (5 x 30
minutes per week)(Department of Health, 2004). We know 71% of the adult
populations in EU member states do not achieve this recommendation
(Sjöström, Oja, Hagströmer, Smith, & Bauman, 2006). Additionally Mead
(Mead, 2009) highlights levels of physical activity in community dwelling
adults with mild motor impairment after stroke are about half those of
healthy older people.
Boysen et al concluded more intense strategies seem to be needed to
promote physical activity after ischaemic stroke. We would advise the
adoption of a person centred consultation approach, based on a theoretical
framework and working towards the current physical activity for health
recommendations before more intensive strategies are adopted. Alternative
outcome measures could also be considered, for example an objective
activity assessment using an activity monitor to assess small increases in
activities of daily living not detected by the PASE. Appropriate
conclusions on the effectiveness of counselling for physical activity in
this patient group could then be made.
Baker, G., Gray, S., Wright, A., Fitzsimons, C., Nimmo, M., Lowry,
R., et al. (2008). The effect of a pedometer-based community walking
intervention "Walking for Wellbeing in the West" on physical activity
levels and health outcomes: a 12-week randomized controlled trial.
International Journal of Behavioral Nutrition and Physical Activity, 5(1),
44.
Boysen, G., Krarup, L.-H., Zeng, X., Oskedra, A., Korv, J., Andersen,
G., et al. (2009). ExStroke Pilot Trial of the effect of repeated
instructions to improve physical activity after ischaemic stroke: a
multinational randomised controlled clinical trial. BMJ, 339(jul20_3),
b2810-.
Campbell, M., Fitzpatrick, R., Haines, A., Kinmonth, A. L.,
Sandercock, P., Spiegelhalter, D., et al. (2000). Framework for design and
evaluation of complex interventions to improve health. BMJ, 321(7262), 694
-696.
Craig, P., Dieppe, P., Macintyre, S., Michie, S., Nazareth, I., &
Petticrew, M. (2008). Developing and evaluating complex interventions: new
guidance.
Department of Health (2004). At least 5 a week: Evidence of the
impact of physical activity and its relationship to health. A report from
the Chief Medical Officer. Department of Health: London.
Hughes, A. R., Mutrie, N., & MacIntyre, P. D. (2007). Effect of
an exercise consultation on maintenance of physical activity after
completion of phase III exercise-based cardiac rehabilitation. European
Journal of Cardiovascular Prevention & Rehabilitation, 14(1), 114 -
121.
Kahn, E. B., Ramsey, L. T., Brownson, R. C., Heath, G. W., Howze, E.
H., Powell, K. E., et al. (2002). The effectiveness of interventions to
increase physical activity. A systematic review. American Journal of
Preventive Medicine, 22, 73 - 107.
Kirk, A., & Mutrie, N. (2007). Physical activity consultation for
people with Type 2 diabetes. Evidence and guidelines. Diabetes Care, 26,
1186-1192.
Kirk, A., Mutrie, N., MacIntyre, P., & Fisher, M. (2003).
Increasing physical activity in people with type 2 diabetes. Diabetes
Care, 26, 1186 - 1192.
Mead, G. E. (2009). Exercise after stroke. British Medical Journal,
doi:10.1136/bmj.b2795.
Rollnick, S., Butler, C. C., McCambridge, J., Kinnersley, P., Elwyn,
G., & Resnicow, K. (2005). Consultations about changing behaviour.
BMJ, 331, 961 - 963.
Sjöström, M., Oja, P., Hagströmer, M., Smith, B. J., & Bauman, A.
(2006). Health-enhancing physical activity across European Union
countries: The Eurobarometer study Journal of Public Health, 14(5), 291-
300.
Competing interests:
None declared
Competing interests: No competing interests
Step counting versus physical activity questionnaire
To the Editor,
We appreciate the suggestion for improvement of the study design of
the ExStroke Pilot Trial (1) by using a step counter instead of using the
Physical Activity Scale for the Elderly (PASE) questionnaire. Ben Ewald
and coworkers compared these two methods in 669 community dwelling persons
with a mean age of 66 years (2). They found a correlation between the two
measures of r=0.37 for women and r=0.30 for men (2). They concluded that
step count had stronger association with health markers like BMI, HDL and
fibrinogen a.o. than PASE. Step counting may be better correlated with
other precise measurements such as BMI, HDL and fibrinogen than the more
subjective PASE.
Ben Ewald and coworkers recruited 901 persons willing to participate
and obtained valid step counts in 669 = 73%. Consequently, 27% did not use
the pedometer or did not have valid results which is insufficient
adherence to a measurement of physical activity used in a randomized
trial. We did consider to use pedometers in the ExStroke Pilot Trial
during the week preceding the control visits, but refrained from it
considering the potential difficulty using such equipment over 24 months
in stroke patients with a mean age of 69 years. Use of a pedometer in the
control group might also act as a stimulus to increase physical activity,
and thereby reduce any difference between the two groups.
It is unknown how step counts relate to risk of stroke. We have shown
that even with inherent imprecision, different PASE scores are related to
the risk of stroke (3). We have also shown that the prestroke PASE was
associated with severity of stroke and with outcome after stroke (4).
Nevertheless, in future trials it might be worth while to consider using a
step counter in addition to a questionnaire.
Although both pedometer and PASE may be associated with other health
markers in stroke patients, this does not turn them into validated
surrogate outcomes for intervention effects on patient important outcomes.
They are both still non-validated, putative surrogate outcome measures
(5).
1 . Boysen G, Krarup L-H, Zeng X, Oskedra A, Korv J, Andersen G, et
al. ExStroke Pilot Trial of the effect of repeated instructions to improve
physical activity after ischaemic stroke: a multinational randomised
controlled clinical trial. BMJ. 2009, 2009;339(jul20_3):b2810-.
2. Ewald B, McEvoy M, Attia J. Pedometer counts superior to physical
activity scale for identifying health markers in older adults. British
Journal of Sports Medicine 2008; doi:10.1136/bjsm.2008.048827
3. Krarup LH, Truelsen T, Pedersen A, Lerke H, Lindahl M, Hansen L, et al.
Level of Physical Activity in the Week Preceding an Ischemic Stroke.
Cerebrovascular Diseases. 2007;24:296-300.
4. Krarup LH, Truelsen T, Gluud C, Andersen G, Zeng X, Kõrv J, Oskedra A,
Boysen G; ExStroke Pilot Trial Group.
Prestroke physical activity is associated with severity and long-term
outcome from first-ever stroke.
Neurology. 2008 Oct 21;71(17):1313-8.
5. Gluud C, Brok J, Gong Y, Koretz RL. Hepatology may have problems with
putative surrogate outcome measures. J Hepatol. 2007;46(4):734-42.
On behalf of
Boysen, G., Krarup, L.-H., Zeng, X., Oskedra, A., Korv, J., Andersen,
G., Gluud C, Pedersen A, Lindahl M, Hansen L, Winkel P, Truelsen T for
the ExStroke Pilot Trial Group
Competing interests:
No competing interests
Competing interests: No competing interests