Single and dual task tests of gait speed are equivalent in the prediction of falls in older people a systematic review and meta analysis

Accepted ManuscriptTitle: Single and dual task tests of gait speed are equivalent in the prediction of falls in older people: a systematic review and This is a PDF file of an unedited ma

Accepted Manuscript

Title: Single and dual task tests of gait speed are equivalent in

the prediction of falls in older people: a systematic review and

This is a PDF file of an unedited manuscript that has been accepted for publication

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Single and dual task tests of gait speed are equivalent in the prediction of falls in older

people: a systematic review and meta-analysis

Jasmine C Menanta,b, Daniel Schoenea,b, Stephen R Lorda,b

Author affiliations:

a Falls and Balance Research Group, Neuroscience Research Australia, PO Box 1165,

Randwick NSW 2031, Australia

b School of Public Health and Community Medicine, University of New South Wales,

UNSW Sydney 2052, Australia

E-Mail: j.menant@neura.edu.au, d.schoene@neura.edu.au, s.lord@neura.edu.au

Professor Stephen Lord, Neuroscience Research Australia, Barker Street, Randwick, NSW, 2031,

Australia

Email: s.lord@neura.edu.au Tel: +61 2 9399 1061 Fax: +61 2 9393 1204

Accepted Manuscript

ABSTRACT

Although simple assessments of gait speed have been shown to predict falls as well as

hospitalisation, functional decline and mortality in older people, dual task gait speed

paradigms have been increasingly evaluated with respect to fall prediction Some studies

have found that dual task walking paradigms can predict falls in older people A systematic

review and meta-analysis was conducted to determine whether dual task walking paradigms

involving a secondary cognitive task have greater ability to predict falls than single walking

tasks The meta-analytic findings indicate single and dual task tests of gait speed are

equivalent in the prediction of falls in older people and sub-group analyses revealed similar

findings for studies that included only cognitively impaired participants, slow walkers or used

secondary mental-tracking or verbal fluency tasks

Keywords

Accidental falls, older people, dual task paradigm, gait speed, cognition, prediction

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1 INTRODUCTION

Over the past two decades, an extensive body of research has shown that walking is not an

automatic activity and that cognition, in particular attention and executive functioning,

contributes significantly to balance and locomotor control (Yogev-Seligman et al., 2008,

Woollacott and Shumway-Cook., 2002) Much of this work has involved dual task paradigms

which typically require participants to divide their attention and concurrently undertake two

or more tasks, usually a cognitive and a motor task In 1997, Lundin-Olsson et al (1997) used

a dual task assessment, the “stops walking while talking test”, in a seminal study of fall risk

in residents of senior housing facilities They found that residents who stopped walking in

order to engage in a conversation had significantly shorter times to a future fall than residents

who could talk without stopping walking

Since then, many studies have investigated cognitive/ motor interference while walking and

its relationship to fall risk in elderly and clinical populations Some of these findings have

been pooled in previous systematic reviews (Al-Yahya et al., 2011, Beauchet et al., 2009,

Chu et al., 2013, Zijlstra et al., 2008) An early review (Zijlstra et al., 2008) included 19

studies with various protocols involving postural control, dynamic balance and gait tasks

performed with and without secondary motor or cognitive tasks This led to a high level of

heterogeneity preventing a meaningful meta-analysis The second review of 15 studies, by

Beauchet et al (2009) found that large dual task costs (i.e the percentage difference between

single and dual task performance in cognitive and/or motor tasks) were associated with a

significant increased odds of falling in older people living in community and residential aged

care settings Al-Yahya and colleagues (2011) included 66 studies and focused on the effect

of cognitive task type on gait The main conclusions were that gait performance was most

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affected when cognitive tasks involving internal interfering factors (such as mental tracking

tasks) were concurrently performed, and that older age and poorer cognitive function were

both strongly associated with gait speed reduction in the dual task conditions Finally, a

meta-analysis of 15 studies demonstrated that mental-tracking tasks yielded significant dual task

costs for fall prediction in older adults while verbal fluency or manual tasks did not (Chu et

al., 2013)

Due to differing study aims, search strategies and review periods, the above systematic

reviews have contained relatively few as well as different sets of the studies now available on

the ability of dual task assessments to predict falls in older people The findings of two

previous meta-analyses (Beauchet et al., 2009, Chu et al., 2013) should also be interpreted

with some caution as they pooled studies that used various walking tasks (some including

transfers and turns), differing secondary cognitive or motor tasks and study populations

varying with respect to residential settings and co-morbidities

Despite the methodological limitations, there appears to be good evidence that dual task

changes in gait performance are associated with significantly increased risk of falls in older

people However, the ability of simple measures of walking speed to predict falls has also

been well-documented (Abellan van Kan et al., 2009, Deandrea et al., 2010), and the added

value of dual task protocols as opposed to single walking tasks in predicting falls in older

people has not been systematically evaluated in a meta-analysis

The primary aim of this systematic review and meta-analysis, therefore, was to determine

whether dual task walking paradigms involving a secondary cognitive task are superior to

single walking tasks in predicting falls in older people Additional aims were to compare the

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value of single and dual task walking speed measures for predicting falls in participant

subgroups (i.e those with and without cognitive impairment, slower and faster walkers) and

whether a dual task: single task walking speed differential with respect to fall prediction is

only apparent for particular secondary cognitive tasks (i.e mental-tracking or verbal fluency

tasks) We focussed on walking speed as this is the most widely used gait measure in clinical

settings as well as the gait measure most often described in published studies of fall risk in

older people

2 METHODS

2.1 Literature Search

We conducted a systematic review of the literature to identify studies which had investigated

the relationship between gait and falls in older people using a dual task paradigm involving a

secondary cognitive task Initially, we updated previous systematic reviews on the topic by

combining their searches (Al-Yahya et al., 2011, Beauchet et al., 2009, Chu et al., 2013,

Zijlstra et al., 2008) We then searched for articles in the following seven electronic

databases: PubMed, Ovid MEDLINE, EMBASE, PsycINFO, CINAHL, Scopus and

Cochrane Central Register of Controlled Trials Individual search strategies were tailored to

each database using the following Medical Subjects Headings (MeSH; in bold) and key

terms:

1 gait OR walking OR locomotion

2 Falls OR Accidental falls OR falling OR faller

3 aged OR aged, 80 and over OR aging OR ageing

4 dual task* OR dual-task* OR cognition OR attention

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5 #1 AND #2 AND #3 AND #4

The search was performed without language restrictions and results were filtered to produce

all publications from 2008 to February 2013 (inclusive of publications published

electronically ahead of print) To identify further possible studies, reference lists of the

previous systematic reviews (Al-Yahya et al., 2011, Beauchet et al., 2009, Chu et al., 2013,

Zijlstra et al., 2008) and all other relevant articles were hand-searched

2.2 Inclusion and exclusion criteria

To be included, articles had to describe studies which evaluated gait at self-selected speed

under single and dual task conditions in older people to either: (i) predict falls, or (ii)

discriminate between fallers and non-fallers based on retrospective data collection

Articles were excluded if: (i) they were individual abstracts, case studies or reviews; (ii) the

focus was on patient groups (for example: Parkinson’s disease, stroke, etc) other than

cognitive impairment; (iii) participants’ mean age was less than 65 years or all participants

were younger than 60 years of age; (iv) the walking task did not involve time or gait speed as

an outcome; (v) the secondary task was not a cognitive task; (vi) subjective scoring systems

were used to assess dual task performance; (vii) they were published in languages other than

Dutch, English, French or German

2.3 Quality assessment

The Quality Assessment of Diagnostic Accuracy in Systematic Reviews (QUADAS) tool was

also used to provide a general standardised rating of methodological quality (Whiting et al.,

2003)

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2.4 Selection of papers and data extraction

The process of manuscripts selection is illustrated in Figure 1 Following the initial database

searches and after removal of duplicates, two independent reviewers (JM and DS) screened

article titles and abstracts based on the inclusion and exclusion criteria defined above The

following information was extracted from each included article: study design, sample size,

residential setting, sample demographics, cognitive screening, fall outcome measure, fall

definition and months of follow-up, walking and cognitive tasks descriptions, prioritisation of

instructions, proportion of fallers and timed results for the single and dual task walking tests

Means and standard deviations of gait speed for non-fallers and fallers in the single and dual

task tests were retrieved from each of the selected full-text articles or sought from the

authors

2.5 Statistical analysis

To determine whether gait speed had a significantly better predictive value for falls in a dual

task versus a single task paradigm, we carried out random-effect meta-analysis models on all

the studies retrieved from the search, using Stata software version X (Stata Corp., College

Station, TX, USA, 2007) A measure of effect size, the Mean Difference (MD) (95%

Confidence Intervals (CI)) between fallers and non-fallers groups’ gait speed was computed

for the single task and the dual task(s) for each study Studies were weighed according to

sample sizes The pooled MD (95% CI) for the single tasks was then compared to that of the

dual tasks using student t-tests (p<0.05) Forest plots displaying the MD and weight for all

the included studies in the single and dual task conditions were generated for gait speed

Heterogeneity between studies was assessed using chi-square (χ2) tests (p < 0.1) and the I2

statistic which quantifies the proportion of variation that is a result of heterogeneity rather

than chance The degree of inconsistency in the studies’ results was considered low, moderate

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and high for values of I2 (expressed in %) around 25%, 50% and 75%, respectively (Higgins

et al., 2003) These steps were repeated for each of the sub-analyses conducted: (i) sensitivity

analysis including only prospective studies, to determine the influence of study design; (ii)

studies including only samples with cognitive impairment; (iii) studies including only straight

walking with no turn; (iv) studies including physically frailer samples based on mean gait

speed for all participants in the single task ≥ 1.0 m.s-1 or < 1.0 m.s-1 (Tiedemann et al., 2008);

(v) studies including only mental tracking secondary tasks (requiring holding and

manipulating information (Al-Yahya et al., 2011, Chu et al., 2013) such as serial subtractions,

reciting alternate letters of the alphabet); (vi) studies including only verbal fluency tasks (for

example: generating as many animal names as possible, as many words starting with a given

letter) (Al-Yahya et al., 2011, Chu et al., 2013)

3 RESULTS

3.1 Studies identified

Our search retrieved 1080 articles of which 33 articles met our inclusion criteria We

requested additional data from the authors for 30 of these studies, of which 26 provided the

data We were not able to obtain the gait speed data for four relevant articles, which where

therefore not included in the meta-analysis (Allali et al., 2010, Faulkner et al., 2007, Koskas

et al., 2010, Theill et al., 2011) Table 1 summarizes the 30 articles that were included in the

meta-analysis; three of them included two groups which were analysed separately (Camicioli

et al., 2006, De Melo et al., 2012, Montero-Odasso et al., 2012); thus 33 samples were

included in the overall meta-analysis (Figure 1)

3.2 Studies population

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The pooled studies yielded a total number of 4144 participants Sample sizes ranged from 11

to 1308 participants Twenty-three studies involved community-dwellers, one recruited

outpatients to a geriatrics department (Reelick et al., 2011) Four studies recruited

participants from senior housing facilities or intermediate care hostels (Beauchet et al.,

2008a, 2008b, Kearns et al., 2012, Pichierri et al., 2012) and two other studies involved

geriatrics and Alzheimer’s care unit inpatients (Camicioli et al., 2006, Kressig et al., 2008)

Fifteen studies clearly indicated that they included participants with no cognitive impairment

(Hall et al., 2011, Tombaugh and McIntyre, 1992, Verghese et al., 2002, Yamada et al.,

2011b) Three studies provided insufficient information regarding the cognitive level of their

participants (Bauer et al., 2010, Uemura et al., 2012, Yamada et al., 2011a) Five studies

included a small percentage (<27%) of participants with cognitive impairment (Donoghue et

al., 2013, Pichierri et al., 2012, Reelick et al., 2011, Trombetti et al., 2011, Verghese et al.,

2002) Seven studies (nine groups) were included in the cognitive impairment sub-analysis

(Beauchet et al., 2008a, 2008b, Camicioli et al., 2006, De Melo et al., 2012, Kearns et al.,

2012, Kressig et al., 2008, Taylor et al., 2013).For all of them, either more than 50% of the

sample recorded MMSE scores <24 (Beauchet et al., 2008a, 2008b), the sample’s mean or

median MMSE score was less than 24 (Kearns et al., 2012, Kressig et al., 2008), or the

participants had a diagnosis of Alzheimer’s disease (Camicioli et al., 2006, De Melo et al.,

2012) Sixteen studies (18 groups) included participants who walked with mean gait speeds

slower than 1m.s-1 in the single task condition

3.3 Methodological quality of included studies

Of the 30 studies included, 11 (12 samples) had a prospective design Six of these had a

12-month follow-up for falls (Beauchet et al., 2008a, 2008b, Liu-Ambrose et al., 2009, Nordin et

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al., 2010, Taylor et al., 2013, Verghese et al., 2002, Yamada et al., 2011a) and one had a

24-month follow-up period (Herman et al., 2010) One study followed up participants until the

time of first fall, up to 12 months, using a wrist sensor to detect falls (Kearns et al., 2012)

Two inpatient studies used bi-weekly chart reviews to identify falls and followed up patients

for approximately 12 months (Camicioli et al., 2006) or 1 month (Kressig et al., 2008) Six

studies (Beauchet et al., 2008a, 2008b, Herman et al., 2010, Liu-Ambrose et al., 2009, Nordin

et al., 2010, Taylor et al., 2013, Yamada et al., 2011a)used monthly calendars or phone calls

to record falls, the gold standard method of falls ascertainment (Lamb et al., 2005); one study

used twice-yearly interviews at six and 12 months post baseline (Verghese et al., 2002)

Baseline gait data from control group participants of randomised controlled trials were used

in eight studies; one with prospective fall follow-up (Liu-Ambrose et al., 2009),and seven

with retrospective fall data (Halvarsson et al., 2011, Pichierri et al., 2012, Silsupadol et al.,

2009, Trombetti et al., 2011, Verghese et al., 2010, Yamada et al., 2010, Yamada et al.,

2011c) Two studies compared non-multiple fallers with multiple fallers (Reelick et al., 2011,

Taylor et al., 2013),and the remainder compared non-fallers and fallers (i.e people who

experienced one or more falls) Less than half the studies provided a detailed definition of a

fall and fall rates varied greatly between studies, ranging from 15% to 90% Four studies had

a history of falls in the past 12 months as an inclusion criterion (Bauer et al., 2010,

Halvarsson et al., 2011, Siu et al., 2008, Trombetti et al., 2011)

Twenty-two studies included only one type of secondary cognitive task and nine studies (ten

samples) included two or more types of secondary cognitive task Most studies used a mental

tracking task (n=28, 31 samples) or a verbal fluency task (n=6, 7 samples) as the cognitive

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task Only two studies used discrimination and decision making secondary tasks (Kearns et

al., 2012, Siu et al., 2008)

In two studies (Liu-Ambrose et al., 2009, Verghese et al., 2002), two levels of complexity of

a task of the same nature (reciting the alphabet and reciting alternate letters of the alphabet)

were used For these studies, only gait speed data recorded in the most complex condition

were included in our analyses

Most studies recorded gait speed during straight line walking; in two studies (Liu-Ambrose et

al., 2009, Verghese et al., 2002) the gait protocol included a turn Similarly, most studies

required participants to walk at a self-selected speed; two studies were unclear about this

specification (Liu-Ambrose et al., 2009, Uemura et al., 2012) Most studies (n=27) specified

the distance for which participants’ gait speed was recorded which ranged from 4.6 m to 25

m Most studies used either an electronic walkway (n=16) or a stopwatch (n=11) to record

gait speed All studies explained the nature of the secondary task to be performed and in 17

studies it was clearly indicated that participants were not to prioritise completing one task

over the other

3.4 Meta-analyses results

The single task and the dual task conditions across all domains investigated significantly

discriminated between fallers and non-fallers (p<0.05) Figure 2 displays the forest plots of

the gait speed variable for all of the studies included in the meta-analysis (n=30) in single

task (top) and dual task (bottom) conditions The pooled MD (95% CI) for gait speed

between fallers and non-fallers in the single task (0.069 (0.045-0.094)) was not significantly

different to that in the dual task condition (0.074 (0.046-0.103)) (Z= 0.266, p=0.790) The

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heterogeneity was moderate for both paradigms (single task: I2=48.0%, χ2=61.5, DF 32,

p=0.002; dual task: I2=58.2%: χ2=76.6, DF 32, p=0.003)

A sensitivity analysis including only prospective falls studies yielded the same

non-significant result (single task 0.044 (0.015-0.072) vs dual task 0.054 (0.025-0.083)) (Z=

0.478, p=0.633), with moderate to low heterogeneity between studies ((single task: I2=32.1%,

χ2=16.19, DF 11, p=0.028; dual task: I2=28.1%: χ2=15.30, DF 11, p=0.001) (Figure 3)

Subgroup meta-analyses revealed no significant differences between pooled MD in gait speed

in the single task vs the dual task conditions amongst people with fast gait speed (mean gait

speed in single task ≥ 1.0 m.s-1) (overall pooled MD (SEM): 0.009 (0.029), Z=-0.306,

p=0.760), slow gait speed (mean gait speed in single task < 1.0 m.s-1) (overall pooled MD

(SEM): 0.001 (0.022), Z=-0.045, p=0.964) (Figure 4), or people with cognitive impairment

(overall pooled MD (SEM): -0.030 (0.029), Z=-1.039, p=0.299) (Figure 5)

The subgroup analyses exploring the type of secondary task indicated that dual task

conditions involving mental tracking tasks (overall pooled MD (SEM): 0.010 (0.018),

Z=0.544, p=0.587) and verbal fluency tasks (overall pooled MD (SEM): -0.666 (0.372),

Z=-1.791, p=0.073) were both not different to single task gait conditions in the prediction of falls

(Figures 6-7)

Restricting the analysis to studies that only included straight line walking showed a similar

pattern of no significant difference (single task 0.067 (0.042-0.092) vs dual task 0.070

(0.040-0.099), (Z= 0.151, p=0.880), with moderate to low heterogeneity between studies

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(single task: I2=46.8%, χ2=56.36, DF 30, p=0.017; dual task: I2=58.2%: χ2=71.72, DF 30,

p=0.0030)

Heterogeneity between studies in the single and dual task conditions dropped below 50% for

the slow gait speed sub-group, and reached minimal levels for the cognitive impairment

group (0% vs 13.8%) and in the verbal fluency tasks (0% for both single and dual task

conditions) sub-analyses

4 DISCUSSION

4.1 Equivalence of single and dual task gait speed in the prediction of falls

This systematic review and meta-analysis of 31 studies revealed that slower gait speeds under

both single and dual task conditions significantly discriminate between fallers and

non-fallers The differences in gait speed between fallers and non-fallers under both conditions

were virtually identical in the main and all sub-group analyses and a sensitivity analysis

confirmed this finding when calculations were restricted to studies with prospective designs

In other words, dual task gait speed offered no clinically or statistically significant benefit

over single task gait speed in either discriminating recent fallers from non-fallers or in

predicting future fallers and non-fallers In all comparisons the difference between means

approached zero with virtually identical CIs Heterogeneity was highest (but acceptable) for

the overall meta-analysis, which can be attributed to a range of between-studies differences

such as residential settings, cognitive and physical status, falls assessment, and dual task

protocols Unsurprisingly, as the studies were pooled in more specific sub-groups,

heterogeneity declined. 

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Several potential reasons for these null findings were explored First, it is possible that the

differential effect of dual task walking on fall risk may only be evident in either in fitter

people who walk quickly or in frailer / high risk groups who require more attentional

resources for balance tasks Contrary to the findings by Yamada et al (Yamada et al., 2011)

who showed that a manual task cost predicted falls in sub-groups of participants who

performed the Timed Up and Go test quickly, we found no indication that dual task gait

speed discriminated fallers from non-fallers better than single task gait speed in the sub-set of

studies in our review that reported mean gait speeds ≥ 1 Further, the findings of equivalence

of single and dual task walking in discriminating between fallers and non-fallers were also

evident in the population groups with reduced mobility (gait speed < 1 m.s-1) and cognitive

impairment Further, other studies that have included patient groups at high risk of falls have

reported similar findings (Hyndman et al., 2006; Smulders et al., 2012) In stroke patients, a

task requiring participants to remember a 7-item shopping list equally affected gait speed in

fallers and non-fallers (Hyndman et al., 2006) and in a large sample of Parkinson’s disease

patients, neither gait variables nor performance in an executive function (Stroop) test were

associated with prospective falls in a dual task paradigm (Smulders et al., 2012)

Secondly, it may be that only certain secondary cognitive tasks adversely influence gait

Other systematic reviews suggest that cognitive tasks that involve internal interfering factors,

such as mental tracking and verbal fluency tasks are more effective at disturbing gait

performance than cognitive tasks involving external interfering factors such as reaction time

tasks (Al-Yahya et al., 2011), and that only dual task costs of mental tracking tasks are

related to fall risk (Chu et al., 2013) However, in our sub-group analyses, we found that in

studies that used only mental tracking or verbal fluency tasks, no significant differences in

pooled MD in gait speed between fallers and non-fallers were evident for the single- and dual

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task conditions There is some preliminary evidence for shared neural networks between

visuo-spatial tasks and balance (Barra et al., 2006, Sturnieks et al., 2008) which would

suggest that secondary tasks involving spatial working memory impair gait function to a

greater extent than mental-tracking tasks In a recent study, we found that older adults walked

slower with increased step time variability and poorer medio-lateral stability (increased

harmonic ratio) when concurrently performing a visuo-spatial task as opposed to an

arithmetic mental tracking task (submitted manuscript) However, whether dual task

paradigms involving visuo-spatial secondary tasks would improve fall prediction is yet to be

verified

Thirdly, it is possible walking speed is not a sufficiently sensitive measure to discriminate

between faller and non-faller groups in dual task paradigms (Beauchet et al., 2008a) Two

studies have reported that a dual task paradigm can improve the prediction of falls when gait

time variability measures are used Herman et al found that swing time variability in a dual

task condition involving mental tracking was an independent predictor of falls status recorded

prospectively over two-years in 262 older community-dwellers as well as a sub-group of 201

participants from this sample who did not report a past fall at baseline (Herman et al., 2010)

In both analyses, usual walking speed was not associated with faller status in either the single

or dual task conditions Kressig et al (2008) reported that stride time variability in dual task

but not single task conditions was significantly associated with the occurrence of a first fall in

57 aged care inpatients Our analyses of this study data indicated no significant differences

between single and dual task gait speed MDs for the fallers and non-fallers (MD (95%CI):

0.020 (0.087), Z=0.230, p=0.818)

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Other studies, however, have not found gait stride or swing time variability measures to be

superior for fall prediction when conducted in dual task as opposed to single task conditions

Springer et al reported a significant faller group x dual task condition interaction, but also

reported significant differences between the faller and non-faller groups for usual gait

measures such as gait speed, swing time and swing time variability (Springer et al., 2006).In

a retrospective study involving 60 participants, Reelick et al (2011) analysed three gait

variability measures (stride length, stride time and stride width) and of these, only one

measure (stride length variability), discriminated significantly between the faller groups in

the dual task, and not the single task, condition Finally, in a prospective study of 64 older

people with cognitive impairment, Taylor et al (2013) found that gait variability measures

(swing time variability and stride length variability) discriminated similarly between fallers

and non-fallers We initially planned to include gait variability measures in our review, but

found most studies did not collect these data and of those that did, the measures were very

heterogeneous and could not be pooled for a meta-analysis

Finally, it may be that the findings should be taken at face value, indicating that gait slowing

(due to underlying reduced balance, strength and coordination) and independent of cognitive

factors (such as poor attention and reduced executive functioning) is primarily important in

relation to fall risk and that the addition of secondary cognitive tasks affects fallers and

non-fallers equally Alternatively, it may be that reduced postural control when walking under

divided attention often results in falls in everyday life, but due to their high correlation,

measures of single or dual task gait speed are equally good indicators of this liability

4.2 Implications for clinical practice

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Our data suggest that with regard to falls in older people, both single and dual task paradigms

are equivalent in their predictive and discriminative validity when gait speed is used The

effect size of the largest single task - dual task difference is less than 0.15 (based on the

largest single task - dual task difference (0.03) divided by the mean gait speed SD from the

four trials with samples with at least 100 fallers and non-fallers (0.22); this effect size is

typically considered small and of dubious clinical utility As gait speed provides a useful

measure of mobility and cut-off values for gait speed have been published with regard to fall

prediction in community-dwellers based on simple walking trials (Callisaya et al., 2011,

Tiedemann et al., 2008),we would suggest that clinicians could retain a simple test of fall risk

along with other pertinent fall history, medication, vision and physical performance measures

in fall risk screening batteries However, if clinicians are seeking further information on

attention and executive functions of their patients, then dual task gait paradigms might be of

value, as the change in gait performance between the single and dual task allows exploring

the attentional requirement of balance during locomotion (Amboni et al., 2013).Such

assessment might in turn guide exercise and cognitive training interventions for older people

to improve multitasking abilities when standing and walking, which are required in many

real-life situations

4.3 Strengths and limitations of the analysis

This is the first meta-analysis focusing on the predictive ability of walking velocity in dual

task vs single task on falls, as previous meta-analyses have focused on dual task costs

(Beauchet et al., 2009, Chu et al., 2013, Zijlstra et al., 2008).The present review required us

to request data from authors for the majority of the studies selected, i.e gait speed data were

not presented for fallers and non-fallers but falls were mentioned as an outcome variable in

the article The inclusion of these data, which was provided by most authors (87%), greatly

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helped minimise a common bias of systematic reviews to only include published data The

main study limitation relates to the unavailability of similar gait variability data for inclusion

in any meta-analyses Another limitation pertains to the inclusion of studies which included a

turn in their protocol, even though a sensitivity analysis which included studies with only

straight line walking yielded the same non-significant results as the primary one

5 CONCLUSION

In conclusion, this meta-analysis indicates that both single and dual task paradigms were

equivalent in predicting falls and discriminating fallers from non-fallers based on gait speed

measurements This finding implies that additional tests of dual task gait speed are not

required for assessing gait in clinical practice and that a simple gait speed measure along with

other pertinent fall history, medication, vision and physical performance measures could be

included in fall risk screening batteries However, dual task gait paradigms may be helpful in

exploring specific attentional and execution function requirements of balance and walking,

which may assist in guiding interventions to maintain cognitive and physical health in older

age

ACKNOWLEDGEMENTS

We thank Mina Sarofim for his assistance with the literature search and data extraction

REFERENCES

Abellan van Kan, G., Rolland, Y., Andrieu, S., Bauer, J., Beauchet, O., Bonnefoy, M., Cesari,

M., Donini, L.M., Gillette Guyonnet, S., Inzitari, M., Nourhashemi, F., Onder, G., Ritz, P.,

Salva, A., Visser, M., Vellas, B., 2009 Gait speed at usual pace as a predictor of adverse

Accepted Manuscript

outcomes in community-dwelling older people an International Academy on Nutrition and

Aging (IANA) Task Force J Nutr Health Aging 13(10), 881-889

Allali, G., Dubois, B., Assal, F., Lallart, E., de Souza, L.C., Bertoux, M., Annweiler, C.,

Herrmann, F.R., Levy, R., Beauchet, O., 2010 Frontotemporal dementia: pathology of gait?

Mov Disord 25(6), 731-737, doi: 10.1002/mds.22927

Al-Yahya, E., Dawes, H., Smith, L., Dennis, A., Howells, K., Cockburn, J., 2011 Cognitive

motor interference while walking: a systematic review and meta-analysis Neurosci Biobehav

Rev 35(3), 715-728, doi: 10.1016/j.neubiorev.2010.08.008

Amboni, M., Barone, P., Hausdorff, J.M., 2013 Cognitive contributions to gait and falls:

Evidence and implications Mov Disord 28(11), 1520-1533, doi: 10.1002/mds.25674

Barra, J., Bray, A., Sahni, V., Golding, J.F., Gresty, M.A., 2006 Increasing cognitive load

with increasing balance challenge: recipe for catastrophe Exp Brain Res 174(4), 734-745

Bauer, C., Gröger, I., Glabasnia, A., Bergler, C., Gassmann, K.G., 2010 First results of

evaluation of a falls clinic International Journal of Gerontology 4(3), 130-136,

http://dx.doi.org/10.1016/S1873-9598(10)70036-3

Beauchet, O., Allali, G., Annweiler, C., Berrut, G., Maarouf, N., Herrmann, F.R., Dubost, V.,

2008a Does change in gait while counting backward predict the occurrence of a first fall in

older adults? Gerontology 54(4), 217-223, doi: 10.1159/000127318

Beauchet, O., Annweiler, C., Allali, G., Berrut, G., Herrmann, F.R., Dubost, V., 2008b

Recurrent falls and dual task-related decrease in walking speed: is there a relationship? J Am

Geriatr Soc 56(7), 1265-1269, doi: 10.1111/j.1532-5415.2008.01766.x

Beauchet, O., Annweiler, C., Dubost, V., Allali, G., Kressig, R.W., Bridenbaugh, S., Berrut,

G., Assal, F., Herrmann, F.R., 2009 Stops walking when talking: a predictor of falls in older

adults? Eur J Neurol 16(7), 786-795, doi: 10.1111/j.1468-1331.2009.02612.x

Accepted Manuscript

Callisaya ML, Blizzard L, Schmidt MD, Martin, K.L., McGinley, J.L., Sanders, L.M.,

Srikanth, V.K., 2011 Gait, gait variability and the risk of multiple incident falls in older

people: a population-based study Age Ageing 40(4), 481-487, doi: 10.1093/ageing/afr055

Camicioli, R., Bouchard, T., Licis, L., 2006 Dual-tasks and walking fast: relationship to

extra-pyramidal signs in advanced Alzheimer disease J Neurol Sci 248(1-2), 205-209

Chu, Y.H., Tang, P.F., Peng, Y.C., Chen H.Y., 2013 Meta-analysis of type and complexity

of a secondary task during walking on the prediction of elderly falls Geriatr Gerontol Int

13(2), 289-297, doi: 10.1111/j.1447-0594.2012.00893.x

De Melo Coelho, F.G., Stella, F., De Andrade, L.P., Barbieri, F.A., Santos-GaldurÓz, R.F.,

Gobbi, S., Costa, J.L., Gobbi, L.T., 2012 Gait and risk of falls associated with frontal

cognitive functions at different stages of Alzheimer's disease Neuropsychol Dev Cogn B

Aging Neuropsychol Cogn 19(5), 644-656, doi: 10.1080/13825585.2012.661398

Deandrea, S., Lucenteforte, E., Bravi, F., Foschi, R., La Vecchia, C., Negri, E., 2010 Risk

factors for falls in community-dwelling older people: a systematic review and meta-analysis

Epidemiology 21(5), 658-668, doi: 10.1097/EDE.0b013e3181e89905

Donoghue, O.A., Cronin, H., Savva, G.M., O'Regan, C., Kenny, R.A., 2013 Effects of fear

of falling and activity restriction on normal and dual task walking in community dwelling

older adults Gait Posture 38(1), 120-124, doi: 10.1016/j.gaitpost.2012.10.023

Faulkner, K.A., Redfern, M.S., Cauley, J.A., Landsittel, D.P., Studenski, S.A., Rosano, C.,

Simonsick, E.M., Shorr, R.I., Ayonayon, H.N., Newman, A.B., Health, Aging, and Body

Composition Study, 2007 Multitasking: association between poorer performance and a

history of recurrent falls J Am Geriatr Soc 55(4), 570-576

Hall, C.D., Echt, K.V., Wolf, S.L., Rogers, W.A., 2011 Cognitive and motor mechanisms

underlying older adults' ability to divide attention while walking Phys Ther 91(7),

1039-1050, doi: 10.2522/ptj.20100114

Accepted Manuscript

Halvarsson, A., Oddsson, L., Olsson, E., Faren, E., Pettersson, A., Ståhle, A., 2011 Effects

of new, individually adjusted, progressive balance group training for elderly people with fear

of falling and tend to fall: a randomized controlled trial Clin Rehabil 25(11), 1021-1031

Herman, T., Mirelman, A., Giladi, N., Schweiger, A., Hausdorff, J.M., 2010 Executive

control deficits as a prodrome to falls in healthy older adults: a prospective study linking

thinking, walking, and falling J Gerontol A Biol Sci Med Sci 65(10), 1086-1092, doi:

10.1093/gerona/glq077

Higgins, J.P., Thompson, S.G., Deeks, J.J., Altman, D.G., 2003 Measuring inconsistency in

meta-analyses BMJ 327(7414), 557-560

Hyndman, D., Ashburn, A., Yardley, L., Stack, E., 2006 Interference between balance, gait

and cognitive task performance among people with stroke living in the community Disabil

Rehabil 28(13-14), 849-856

Kearns, W.D., Fozard, J.L., Becker, M., Jasiewicz, J.M., Craighead, J.D., Holtsclaw, L.,

Dion, C., 2012 Path Tortuosity in Everyday Movements of Elderly Persons Increases Fall

Prediction Beyond Knowledge of Fall History, Medication Use, and Standardized Gait and

Balance Assessments J Am Med Dir Assoc 13(7), 665.e7-665.e13, doi:

10.1016/j.jamda.2012.06.010

Koskas, P., Saad, S., Belqadi, S., Drunat, O., 2010 Gait analysis with simple and dual-task

paradigm in community-dwelling old people attending a geriatric outpatient clinic Rev

Neurol (Paris) 166(3), 321-327, doi: 10.1016/j.neurol.2009.07.009

Kressig, R.W., Herrmann, F.R., Grandjean, R., Michel, J.P., Beauchet, O., 2008 Gait

variability while dual-tasking: fall predictor in older inpatients? Aging Clin Exp Res ;20(2),

123-130

Lamb, S.E., Jorstad-Stein, E.C., Hauer, K., Becker, C., Prevention of Falls Network Europe

and Outcomes Consensus Group, 2005 Development of a common outcome data set for fall

Accepted Manuscript

injury prevention trials: the Prevention of Falls Network Europe consensus J Am Geriatr Soc

53(9), 1618-1622

Liu-Ambrose, T., Katarynych, L.A., Ashe, M.C., Nagamatsu, L.S., Hsu, C.L., 2009

Dual-task gait performance among community-dwelling senior women: the role of balance

confidence and executive functions J Gerontol A Biol Sci Med Sci 64(9), 975-982, doi:

10.1093/gerona/glp063

Lundin-Olsson, L., Nyberg, L., Gustafson, Y., 1997 "Stops walking when talking" as a

predictor of falls in elderly people Lancet 349(9052), 617

Montero-Odasso, M., Muir, S.W., Speechley, M., 2012 Dual-task complexity affects gait in

people with mild cognitive impairment: the interplay between gait variability, dual tasking,

and risk of falls Arch Phys Med Rehabil 93(2), 293-299, doi: 10.1016/j.apmr.2011.08.026

Nordin, E., Moe-Nilssen, R., Ramnemark, A., Lundin-Olsson, L., 2010 Changes in

step-width during dual-task walking predicts falls Gait Posture 32(1), 92-7, doi:

10.1016/j.gaitpost.2010.03.012

Pichierri, G., Murer, K., de Bruin, E.D., 2012 A cognitive-motor intervention using a dance

video game to enhance foot placement accuracy and gait under dual task conditions in older

adults: a randomized controlled trial BMC Geriatr 12:74, doi: 10.1186/1471-2318-12-74

Reelick, M.F., van Iersel, M.B., Kessels, R.P., Rikkert, M.G., 2009 The influence of fear of

falling on gait and balance in older people Age Ageing 38(4), 435-340 doi:

10.1093/ageing/afp066

Reelick, M.F., Kessels, R.P., Faes, M.C., Weerdesteyn, V., Esselink, R.A., Olde Rikkert, G.,

2011 Increased intra-individual variability in stride length and reaction time in recurrent

older fallers Aging Clin Exp Res 23(5-6), 393-399, doi: 10.3275/7327

Silsupadol, P., Shumway-Cook, A., Lugade, V., van Donkelaar, P., Chou, L.S., Mayr, U.,

Woollacott, M.H., 2009 Effects of single task versus dual-task training on balance

Accepted Manuscript

performance in older adults: a double-blind, randomized controlled trial Arch Phys Med

Rehabil 90(3), 381-387, doi: 10.1016/j.apmr.2008.09.559

Siu, K.C., Lugade, V., Chou, L.S., van Donkelaar, P., Woollacott, M.H., 2008 Dual-task

interference during obstacle clearance in healthy and balance-impaired older adults Aging

Clin Exp Res 20(4), 349-354

Smulders, K., Esselink, R.A., Weiss, A., Kessels, R.P., Geurts, A.C., Bloem, B.R., 2012

Assessment of dual tasking has no clinical value for fall prediction in Parkinson's disease J

Neurol 259(9), 1840-1847

Springer, S., Giladi, N., Peretz, C., Yogev, G., Simon, E.S., Hausdorff, J.M., 2006

Dual-tasking effects on gait variability: the role of aging, falls, and executive function Mov Disord

21(7), 950-957

Sturnieks, D.L., St George, R., Fitzpatrick, R.C., Lord, S.R., 2008 Effects of spatial and

nonspatial memory tasks on choice stepping reaction time in older people J Gerontol A Biol

Sci Med Sci 63(10), 1063-1068

Taylor, M.E., Delbaere, K., Mikolaizak, A.S., Lord, S.R., Close, J.C.T., 2013 Gait parameter

risk factors for falls under simple and dual task conditions in cognitively impaired older

people Gait and Posture 37(1), 126-130, doi: 10.1016/j.gaitpost.2012.06.024

Theill, N., Martin, M., Schumacher, V., Bridenbaugh, S.A., Kressig, R.W., 2011

Simultaneously measuring gait and cognitive performance in cognitively healthy and

cognitively impaired older adults: the Basel motor-cognition dual-task paradigm J Am

Geriatr Soc 59(6), 1012-1018, doi: 10.1111/j.1532-5415.2011.03429.x

Tiedemann, A., Shimada, H., Sherrington, C., Murray, S., Lord, S., 2008 The comparative

ability of eight functional mobility tests for predicting falls in community-dwelling older

people Age Ageing 37(4), 430-435, doi: 10.1093/ageing/afn100

Accepted Manuscript

Tombaugh, T.N., McIntyre, N.J., 1992 The mini-mental state examination: a comprehensive

review J Am Geriatr Soc 40(9), 922-935

Trombetti, A., Hars, M., Herrmann, F.R., Kressig, R.W., Ferrari, S., Rizzoli, R., 2011 Effect

of music-based multitask training on gait, balance, and fall risk in elderly people: a

randomized controlled trial Arch Intern Med 171(6), 525-533, doi:

10.1001/archinternmed.2010.446

Uemura, K., Yamada, M., Nagai, K., Shinya, M., Ichihashi, N., 2012 Effect of dual-tasking

on the center of pressure trajectory at gait initiation in elderly fallers and non-fallers Aging

Clin Exp Res 24(2), 152-156

Verghese, J., Buschke, H., Viola, L., Katz, M., Hall, C., Kuslansky, G., Lipton, R., 2002

Validity of divided attention tasks in predicting falls in older individuals: a preliminary study

J Am Geriatr Soc 50(9), 1572-1576

Verghese, J., Mahoney, J., Ambrose, A.F., Wang, C., Holtzer, R., 2010 Effect of cognitive

remediation on gait in sedentary seniors J Gerontol A Biol Sci Med Sci 65(12), 1338-1343,

doi: 10.1093/gerona/glq127

Whiting, P., Rutjes, A.W., Reitsma, J.B., Bossuyt, P.M., Kleijnen, J., 2003 The development

of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in

systematic reviews BMC Med Res Methodol 3:25, doi: 10.1186/1471-2288-3-25

Woollacott, M., Shumway-Cook, A., 2002 Attention and the control of posture and gait: a

review of an emerging area of research Gait Posture 16(1), 1-14

Yamada, M., Aoyama, T., Arai, H., Nagai, K., Tanaka, B., Uemura, K., Mori, S., Ichihashi,

N., 2011a Dual-task walk is a reliable predictor of falls in robust elderly adults J Am Geriatr

Soc 59(1), 163-164, doi: 10.1111/j.1532-5415.2010.03206.x

Yamada, M., Aoyama, T., Nakamura, M., Tanaka, B., Nagai, K., Tatematsu, N., Uemura, K.,

Nakamura, T., Tsuboyama, T., Ichihashi, N., 2011b The reliability and preliminary validity

Accepted Manuscript

of game-based fall risk assessment in community-dwelling older adults Geriatr Nurs 32(3),

188-194, doi: 10.1016/j.gerinurse.2011.02.002

Yamada, M., Aoyama, T., Tanaka, B., Nagai, K., Ichihashi, N., 2011c Seated stepping

exercise in a dual-task condition improves ambulatory function with a secondary task: a

randomized controlled trial Aging Clin Exp Res 23(5-6), 386-392, doi: 10.3275/7326

Yamada, M., Tanaka, B., Nagai, K., Aoyama, T., Ichihashi, N., 2010 Trail-walking exercise

and fall risk factors in community-dwelling older adults: Preliminary results of a randomized

controlled trial J Am Geriatr Soc 58(10), 1946-1951, doi:

10.1111/j.1532-5415.2010.03059.x

Yogev-Seligmann, G., Hausdorff, J.M., Giladi, N., 2008 The role of executive function and

attention in gait Mov Disord 23(3), 329-342

Zijlstra, A., Ufkes, T., Skelton, D.A., Lundin-Olsson, L., Zijlstra, W., 2008 Do dual tasks

have an added value over single tasks for balance assessment in fall prevention programs? A

mini-review Gerontology 54(1), 40-49, doi: 10.1159/000117808

CONTRIBUTORS

JM and SL contributed to the conception and design of the review JM and DS contributed to

the literature searching, data extraction and analysis JM and SL drafted the article and DS

revised the article for important intellectual content All authors approved the final version

FUNDING

This study was funded by NeuRA internal funds

CONFLICTS OF INTEREST