Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 26

Temporal stability of psychological factors post-stroke
an explanation for the negative changes observed in
psychological factors.
Although the occurrence of stroke provides a pos-
sible explanation for the significant differences over
time on all measures except for passive coping, it
remains unclear whether damage to the brain (i.e. the
stroke) or the fact that a stroke is a negative life event
(such as a cardiac event) or the chronic character (as in
other diseases, such as diabetes) or their combination
may induce changes in psychological factors. From
earlier studies we know that patients with acquired
brain injury make more use of passive reactions and
less use of problem-solving coping styles than the
general population (7), which may be related to the
damage to the brain. From studies on survivors of a
cardiac arrest we know that the impact of the event
plays an important role in the quality of life in the
long term (34); therefore distress may also influence
psychological functioning. A study on chronic diseases
(35) also found changes over time in extraversion and
neuroticism after the onset of chronic diseases, such
as heart disease, respiratory disease and stroke. Future
studies are needed to relate the observed negative
changes to stroke, brain damage, a negative life event,
chronic character of the disease or their combination.
Furthermore, one could argue whether these changes
comply with the minimal clinically relevant change
of these measures and therefore represent clinically
relevant changes and/or changes due to measurement
error. Because this information is not available, we
chose 0.5 SD as pragmatic indicator of change, as sug-
gested by Norman et al. (26). Future research should
provide the minimal clinically relevant change per
measure to investigate whether the changes observed
in this study represent clinically relevant changes.
Even if the observed changes do not reflect clinically
relevant changes and thus suggest temporal stability,
our findings imply, at the very least, that the psycho-
logical factors investigated do not improve naturally
to a more beneficial level and, consequently, do not
foster improved outcomes in terms of participation
and quality of life.
To examine whether psychological factors can be
modified by treatment programmes, systematic re-
views and meta-analyses provide some evidence for
the ability to change depression, anxiety, self-efficacy
and coping by means of psychological therapy, to pos-
sibly improve the outcomes of patients with stroke
in terms of quality of life and participation (36–40).
Given these positive findings related to the modifia-
bility of some psychological factors, treatment could
be aimed at enhancing adaptive psychological factors
and limiting maladaptive psychological factors in
order to improve participation and quality of life of
23
patients with stroke. However, to provide more insight
for the development of such focused and personalized
treatment, future research should reveal which patients
are at risk of the negative changes over time regarding
psychological factors.
Another implication is related to the occurrence of
2 clusters, namely an “adaptive psychological factor”
(proactive coping, self-efficacy, extraversion) and a
“maladaptive psychological factor” (passive coping
and neuroticism). This could suggest the use of a single
measure of adaptive psychological factors and a single
measure of maladaptive psychological factors for
subsequent studies. However, more research is needed
to replicate these findings and provide direction for
the selection or development of such measures. Also
it should be noted that at 2 months post-stroke, pes-
simism did not load on the extracted factors, whereas
optimism loaded on both factors. At 2 years post-stro-
ke, pessimism did load on the adaptive psychological
factor, but optimism, although inverted, also loaded
on this maladaptive factor and not, as expected, on
the adaptive factor.
While interpreting the results of our study, the fol-
lowing limitations should be taken into account. First,
the homogeneous sample could limit the generaliza-
bility of our results to the entire stroke population
or to other patient populations. Most patients in our
study had a minor ischaemic stroke. An explanation
for this homogeneity is that mild stroke comprises the
largest group of stroke patients and patients with a
severe ischaemic stroke or a haemorrhagic stroke are
less often present, are less often referred to general
hospitals, have greater difficulty understanding the
questionnaires or study instructions and are less able
to provide informed consent within the first week (4).
Future research could investigate the temporal stability
of psychological factors in patients with a more severe
or haemorrhagic stroke. Furthermore, it would be inte-
resting to examine whether, in other patient populations
with mild brain injuries, such as mild TBI, or in other
chronic diseases with a sudden onset, the same negative
effect of time is seen to reveal whether these changes
are specific for a mild brain injury (stroke or mild
TBI) or related to a more general cause, such as the
onset of a disabling chronic disease or occurrence of
other significant (health-related) life events. Secondly,
psychological factors were measured at 2 time-points,
22 months apart. To provide evidence for the existence
of linear or non-linear time effects and to reveal time-
related changes within this time period psychological
factors should ideally be assessed at more time-points.
Thirdly, time-dependent relationships with regard to
depression, anxiety and other psychological factors,
such as locus of control, sense of coherence and resi-
J Rehabil Med 51, 2019