Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 77

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K. Akizuki et al.
Table III. Comparison between the “faller” and “’non-faller”
groups after matching (n  = 16)
Faller
(n  = 8)
Age, years, mean (SD)
Sex, female, n
Height, cm, mean (SD)
Weight, kg, mean (SD)
MLSI, °, mean (SD)
FRT, cm, mean (SD)
TUG, s, mean (SD)
Non-faller
(n  = 8)
70.6 (3.8)
69.0 (3.5)
6
6
155.5 (8.9) 158.0 (7.8)
53.9 (11.1) 53.2 (8.9)
9.1 (1.0)
8.1 (0.2)
28.3 (4.8)
26.6 (4.5)
8.3 (0.8)
7.9 (0.7)
p-value Cohen’s d
0.387 0.477
0.566
0.905
0.016
0.478
0.268 0.314
0.065
1.468
0.390
0.617
MLSI: Medial-Lateral Stability Index, FRT: Functional Reach Test, TUG: Timed
Up and Go. All comparisons between the 2 groups were performed using
independent t-tests.
significant between-group difference was identified
only for the Unstable Board Balance Test (p = 0.016,
Cohen’s d = 1.468), with no difference for the FRT
(p = 0.478, Cohen’s d = 0.390) or TUG (p = 0.268,
Cohen’s d = 0.617).
Fig. 3 shows the ROC curve for each balance
performance score, with the optimal cut-off value,
AUC sensitivity, specificity, PLR, and NLR for each
reported in Table IV. The AUC was greater for the
Unstable Board Balance Test (0.78), compared with
the FRT (0.64) and TUG (0.54). In addition, the cut-
off values calculated from the ROC curve were 8.6°
for the Unstable Board Balance Test (sensitivity 0.67;
specificity 0.87; PLR 4.95; NLR 0.39), 30.7 cm for
1
0.8
0.6
0.4
MLSI
FRT
0.2
TUG
0
0
0.2
0.4
1
0.8
Fig. 3. Receiver operating characteristic (ROC) curves for identifying
a recent fall.
Table IV. Characteristics of each test
Cut-off
value AUC (95% CI)
0.6
1－Specificity
MLSI
FRT
TUG
8.6
30.7
7.3
Sensitivity Specificity PLR
0.780 (0.607–0.955) 0.667
0.643 (0.443–0.843) 0.778
0.540 (0.325–0.754) 0.333
0.865
0.500
0.942
NLR
4.952 0.385
1.556 0.444
5.778 0.707
MLSI: Medial-Lateral Stability Index; FRT: Functional Reach Test; TUG: Timed
Up and Go; AUC: Area under the Curve; CI: confidence interval; PLR: positive
likelihood ratio; NLR: negative likelihood ratio.
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the FRT (sensitivity 0.78; specificity 0.50; PLR 1.56;
NLR 0.44) and 7.3 s for the TUG (sensitivity 0.33;
specificity 0.94; PLR 5.78; NLR 0.71).
DISCUSSION
This study examined the comparative usefulness of
the Unstable Board Balance Test, FRT and TUG to
differentiate fallers from non-fallers among a group
of health and high-functioning, community-dwelling,
elderly individuals. The TUG and FRT are commonly
used in clinical practice (and research) for the assess-
ment of balance control, both of which can be asses-
sed rapidly. The BBS was not used due to its ceiling
effect, with healthy, active, individuals achieving the
maximum score (13, 15). As our group of interest was
healthy community-dwelling elderly individuals, we
set our inclusion criteria to persons who could walk
independently, without an assistive device, and could
visit the facility for assessment by themselves. These
criteria allowed us to recruit a group of high-functio-
ning individuals for whom existing fall assessment
tests (TUG and FRT) could not discriminate the fall
risk. Among study group, 14.8% of subjects had expe-
rienced a fall over the previous year, an incidence rate
which was lower than previously reported (25). We do
need to consider that individuals might have selected
to not report a fall, due to pride or embarrassment
(26), resulting in some fallers being included in the
non-faller group. Regardless of this potential error, the
TUG and FRT could not reliably discriminate between
fallers and non-fallers. In a previous study, standard
values (calculated from a meta-analysis) of 8.1 s have
been reported for individuals 60–69 years of age, and
9.2 s for those 70–79 years of age (27), with values
for subjects in our study being comparable to these
standard values. However, the FRT value for our study
group was greater than the standard value previously
reported for elderly individuals of 29.4 cm (28). The
high function of our study group probably explains the
inability of the FRT and TUG to differentiate between
fallers and non-fallers. However, despite being high
functioning, 14.8% of the people had experienced a
fall within the past year, a finding which is consistent
with the rate of fall previously reported in healthy and
high-functioning elderly individuals (16, 29). Of note,
the Unstable Board Balance Test reliability discrimi-
nated between fallers and non-fallers, and this in the
absence of any self-reported difficult with walking.
The current study demonstrates that the MLSI can
discriminate between fallers and non-fallers, which
was not possible using the TUG or FRT. Moreover,
matching increased the effect size of discrimination
for the MLSI and TUG, but decreased the effect size