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T. Winairuk et al.
responsiveness (large SRM), suggesting all 4 versions of
the BESTest were sensitive in detecting the effectiveness
of rehabilitation in subacute stroke. Results regarding ac-
ceptable SRM were in accordance with previous studies
on psychometric properties of the BESTest in patients
with subacute and community-dwelling stroke (13, 15,
17). However, when considering the external responsi-
veness using the BBS as the reference, our study sho-
wed that only the S-BESTest and the original BESTest
demonstrated higher accuracy in identifying the patients
with subacute stroke who had balance improvement with
the mean MCID of 6 and 16 points, respectively. Better
external responsiveness of the S-BESTest in the patients
with subacute stroke, compared with the Brief-BESTest
and the Mini-BESTest, may be due to the fact that the
S-BESTest was developed specifically for patients with
stroke. With 13 items that preserve all 6 domains of the
original BESTest, the S-BESTest is likely to be better
at representing impairments and activity limitations of
patients with stroke than the other short forms of the
BESTest. For example, patients with stroke demonstra-
ted larger mediolateral postural swaying than healthy
subjects, while antero-posterior swaying was similar
between the groups (37). The item “functional reach
lateral on non-paretic side” was therefore included in
the S-BESTest to represent the impairment of the paretic
trunk muscles to maintain posture when reaching toward
the non-paretic side, whereas the brief-BESTest contains
the item “functional reach forward”. Another example
was the item “rise to toes”, which was included in the
S-BESTest. This item can capture another common
problem in stroke, where impairment of tibialis anterior
would limit its anticipatory action, leading to inability to
perform rise to toes in patients with stroke (38).
Although previous studies reported a high recovery
rate in the lower extremity at 1–4 weeks post-stroke and
a plateau phase of recovery after 6 months with smaller
score changes (39, 40), this study found that internal re-
sponsiveness and external responsiveness (using BBS as
reference) were lower at 2–4 weeks compared with the
first 2 weeks post-rehabilitation. The larger recovery oc-
curring in the first 2 weeks post-rehabilitation could be
due to the spontaneous recovery of body functions from
cerebrovascular injury, such as reduction in inflamma-
tion and swelling in the brain, which occurs intensively
during the first few weeks post-stroke, together with the
body adaptation from rehabilitation (39, 40). We also
demonstrated that the minimal clinically important dif-
ference (MCID) of the S-BESTest, the Brief-BESTest,
the Mini-BESTest, and the BESTest calculated using
the BBS score change was more accurate than those
calculated using the GRC score change. The GRC score
was obtained from patient’s perception that may result
in underestimation or overestimation from recall bias,
www.medicaljournals.se/jrm
personal experiences and the ability to understand the
context of improvement (33).
This study has several limitations concerning gene-
ralization to different cluster groups and location. The
S-BESTest was developed from patients with stroke who
were able to stand independently for at least 3 s. This
scale should be investigated further in patients who are
unable to stand or dependence in standing. Total assess-
ment time for each patient was approximately 1.5 h. Such
lengthy assessment may lead to fatigue of individual,
which may interfere with test results, but the administra-
tion of the S-BESTest in a clinical setting will be free of
fatigue due to shorter assessment time. Moreover, the
clinician should be aware that the method of scoring the
shortened version of the BESTest in this study may not
be the same as that in real practice, as we extracted the
scores of shortened versions of the BESTest from the
scores of the full BESTest. Lastly, the responsiveness
of our study was carried out for a duration of 4 weeks
post-rehabilitation, when the recovery process is still
occurring although slowly. It will be useful to determine
the MCID for the later phase of the recovery period.
In conclusion, all 4 versions of the BESTest, the S-
BESTest, Brief-BESTest, Mini-BESTest and BESTest,
had excellent reliability, high concurrent validity with
the BBS in patients with subacute stroke and high in-
ternal responsiveness. However, only the S-BESTest
demonstrated no significant floor-ceiling effect and
high external responsiveness to identify balance im-
provement similar to the original BESTest. Therefore,
the S-BESTest is a short version of the BESTest that
is appropriate for use in assessing postural control
impairments in patients with subacute stroke.
ACKNOWLEDGEMENTS
The authors thank the physical therapists at Lerdsin Hospital
in Bangkok, Thailand for offering their facilities and a location
for patient recruitment.
Funding: This study was supported by the Thailand Research
Fund (grant number RSA5580002) and the National Research
Council of Thailand (grant number 073/2560).
The authors have no conflicts of interest to declare.
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