Journal of Rehabilitation Medicine 51-10 | Page 39

Physical activity before stroke
relatively good function, being able to walk and move
about. Other features, such as becoming depressed after
a stroke, might also lead to less post-stroke PA, although
the literature confirming this is sparse (21). One in 4
reported a higher activity level, while 1 in 3 reported a
lower activity level after stroke. We do not have informa-
tion about which of these patients received physiotherapy
or other support-enhancing activity. However, as most
patients increased or decreased their activity only one
level, the observed variation may be within expected
measurement error of the self-report PA instrument. Test-
retest reliability of the HUNT questions was considered
to be moderately good regarding hard PA ( w κ = 0.41), but
poor regarding light activity ( w κ = 0.2) (29). Compared
with other measures of PA, such as VO 2max , the ques-
tions concerning light PA correlated poorly (r = 0.03),
while the questions about hard PA showed a moderate
correlation (r = 0.46) (29). It is not certain that one level
change in PA represent a true change in activity level,
and it might be more realistic to consider the extreme
changes as true changes. In fact, most patients appeared
to be quite consistent in their pre- and post-stroke activity
level, which was not in accordance with our hypothesis
of lower activity levels after stroke. The reason for this
might be the selection of patients favouring those with
less severe strokes to this study. Some may also live
with the impression of being as active after as before the
stroke, even though this might not be the case.
Study limitations
Because of the observational design, the ability to
identify causal relationships was limited, and despite
adjusting the analyses for possible confounding factors,
it was difficult to eliminate the risk of other variables
influencing the results. Physical disability, stroke se-
verity, history of depression and cognitive impairment
are variables known to be associated with depression
after stroke (2). The regression analyses were adjusted
for stroke severity and pre-stroke functional disability,
but history of depression and cognitive impairment
were not examined in this study. Functional disability
was significantly associated with both depression and
anxiety, but PA and depression showed an association
independent of functional disability. Information about
pre-stroke mental health would have made it possible
to distinguish between depression and anxiety that
occurred before and after the stroke, as these entities
might have different causes and progression. The use of
medications for depression or anxiety might confound
the effect of PA on depression and anxiety, and our
analyses are limited by the lack of this information.
Another variable that might interfere with both PA,
mood and anxiety is fatigue (36, 37). However, the
relationships appear to be complex, especially between
759
fatigue and depression, as fatigue might be a part of
a depressive state as well as an isolated phenomenon.
The advantage of self-report schemes is that they are
easy and cheap to apply, particularly in large patient
groups. However, people tend to overestimate their
volume of PA compared with when PA is measured
with an activity measuring device (38). Hence, the
actual activity level was probably lower than reported
in this study. However, when it comes to pre-stroke
activity level, there exist no recommendations for other
plausible methods (39).
Another limitation with the self-report schemes is
that they are subjective, requiring a certain level of
cognitive function among participants, both when
evaluating their own level of PA, and when completing
the scheme, or it requires that they have a next of kin
who can assist them. Asking about activity levels for
the last year before the stroke introduces a risk of recall
bias, and it is probably difficult to give good estimates
for such a long time. Other more objective methods of
assessing PA, such as activity-monitoring chips (40),
are expensive in such a high number of patients, and
were therefore not used in this study. However, such
methods are recommended for use in further research.
Conclusion
This study shows that a higher level of PA before stroke
is associated with fewer symptoms of depression after
stroke, but not with symptoms of anxiety. Pre- and
post-stroke self-reported activity levels appeared to
be quite consistent. Although limited to associations,
this study supports the benefits of PA in the general
population in order to improve outcome and lessen
the impact of stroke. Hence, future studies should be
designed to confirm the benefit of PA in primary and
secondary prevention of emotional distress after stroke.
ACKNOWLEDGEMENTS
The authors would like to thank Mari Gunnes and Christine Sandø
Lundemo for their participation in collecting data.
This work was supported by the Liaison Committee between
the Central Norway Regional Health Authority, the Norwegian
University of Science and Technology and the Research Council
of Norway [grant number 205309].
The authors have no conflicts of interest to declare.
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J Rehabil Med 51, 2019