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 Manuscript Title: Single and dual task tests of gait speed are equivalent in the prediction of falls in older people: a systematic review and meta-analysis Author: Jasmine C Menant Daniel Schoene Stephen R Lord PII: DOI: Reference: S1568-1637(14)00064-6 http://dx.doi.org/doi:10.1016/j.arr.2014.06.001 ARR 524 To appear in: Ageing Research Reviews Received date: Revised date: Accepted date: 26-2-2014 26-5-2014 2-6-2014 Please cite this article as: Menant, J.C., Schoene, D., Lord, S.R.,Single and dual task tests of gait speed are equivalent in the prediction of falls in older people: a systematic review and meta-analysis, Ageing Research Reviews (2014), http://dx.doi.org/10.1016/j.arr.2014.06.001 This is a PDF file of an unedited manuscript that has been accepted for publication As a service to our customers we are providing this early version of the manuscript The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain Single and dual task tests of gait speed are equivalent in the prediction of falls in older people: a systematic review and meta-analysis cr ip t Jasmine C Menanta,b, Daniel Schoenea,b, Stephen R Lorda,b Author affiliations: Falls and Balance Research Group, Neuroscience Research Australia, PO Box 1165, us a b an Randwick NSW 2031, Australia School of Public Health and Community Medicine, University of New South Wales, M UNSW Sydney 2052, Australia Ac ce p te d E-Mail: j.menant@neura.edu.au, d.schoene@neura.edu.au, s.lord@neura.edu.au Corresponding author: Professor Stephen Lord, Neuroscience Research Australia, Barker Street, Randwick, NSW, 2031, Australia Email: s.lord@neura.edu.au Tel: +61 9399 1061 Fax: +61 9393 1204 Page of 52 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 ip t 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 cr 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 us tasks The meta-analytic findings indicate single and dual task tests of gait speed are an 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 te Keywords d M secondary mental-tracking or verbal fluency tasks Ac ce p Accidental falls, older people, dual task paradigm, gait speed, cognition, prediction Page of 52 INTRODUCTION Over the past two decades, an extensive body of research has shown that walking is not an ip t automatic activity and that cognition, in particular attention and executive functioning, contributes significantly to balance and locomotor control (Yogev-Seligman et al., 2008, cr 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 us or more tasks, usually a cognitive and a motor task In 1997, Lundin-Olsson et al (1997) used an 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 M order to engage in a conversation had significantly shorter times to a future fall than residents d who could talk without stopping walking te 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 Ac ce p 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 Page of 52 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- ip t 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 cr al., 2013) us Due to differing study aims, search strategies and review periods, the above systematic an 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 M 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 d transfers and turns), differing secondary cognitive or motor tasks and study populations te varying with respect to residential settings and co-morbidities Ac ce p 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 Page of 52 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 ip t 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 cr settings as well as the gait measure most often described in published studies of fall risk in an us older people METHODS M 2.1 Literature Search We conducted a systematic review of the literature to identify studies which had investigated d the relationship between gait and falls in older people using a dual task paradigm involving a te 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, Ac ce p 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: gait OR walking OR locomotion Falls OR Accidental falls OR falling OR faller aged OR aged, 80 and over OR aging OR ageing dual task* OR dual-task* OR cognition OR attention Page of 52 #1 AND #2 AND #3 AND #4 The search was performed without language restrictions and results were filtered to produce ip t all publications from 2008 to February 2013 (inclusive of publications published electronically ahead of print) To identify further possible studies, reference lists of the cr previous systematic reviews (Al-Yahya et al., 2011, Beauchet et al., 2009, Chu et al., 2013, us Zijlstra et al., 2008) and all other relevant articles were hand-searched an 2.2 Inclusion and exclusion criteria To be included, articles had to describe studies which evaluated gait at self-selected speed M 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 d Articles were excluded if: (i) they were individual abstracts, case studies or reviews; (ii) the te 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 Ac ce p 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) Page of 52 2.4 Selection of papers and data extraction The process of manuscripts selection is illustrated in Figure Following the initial database searches and after removal of duplicates, two independent reviewers (JM and DS) screened ip t 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, cr residential setting, sample demographics, cognitive screening, fall outcome measure, fall definition and months of follow-up, walking and cognitive tasks descriptions, prioritisation of us instructions, proportion of fallers and timed results for the single and dual task walking tests an 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 M authors d 2.5 Statistical analysis te 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 Ac ce p 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 (p3 extrapyramidal signs Herm an et al, 2010 Community dwelling participating in longitudinal study on gait & falls Inclusion criteria: free from disease directly impacting gait, major depression, acute illness or history of brain surgery; MMSE≥25 Ac c ep te Camic ioli et al., 2006 n=226 and n=223 at baseline and followup, respectiv ely, with full followup – out of initial 262 (60.3% 70-90 years; 76.3 (4.3) Nonfallers vs ≥1 fall "Unintenti onally coming to rest on a lower surface" ip t cr 0.53(0.16) vs 0.51(0.16) us ants with MMSE score 16-25, informa tion obtaine d from carer Prospec tive from biweekly chart reviews ; an MMSE:16-24) mean (SD) follo w-up days: EPS:335( 71.8) EPS+ : 269.7 (76) 4.6m (15ft) walk at selfselected comfortable speed – Gaitrite mat DT1: Mental tracking: Forward counting by from No EPS-: (15% ) EPS+ :16 (55% ) EPS-: ST NF vs fallers (n: 11/2): 0.80(0.15) vs.0.70(0.16) DT1 NF vs fallers (n: 11/2): 0.77(0.15) vs 0.59(0.41) EPS+: ST NF vs fallers (n: 13/16): 0.56(0.29) vs 0.61(0.20) DT1 NF vs fallers (n:13/16): 0.59(0.29) vs 0.62(0.24) Monthl y falls calenda rs – telepho ne calls if data missing 24 mont hs 25m walk at self-selected comfortable speed for 2min – forcesensitive insoles DT1: Mental tracking: Serial subtractions by 3‟s from a predefined three-digit number No 122/2 26 (ie 54.0 % single task) 120/2 23 (ie 53.8 %) ST NF vs fallers (n: 104/122): 1.26(0.21) vs 1.24(0.20) DT1 NF vs fallers (n: 103/120): 1.15(0.20) vs 1.10(0.22) Page 41 of 52 LiuAmbr ose et al, 2009 n=57 “ Involuntar y change of posture, whereby a patient ended up lying on the floor” 140 (100%) but DT data only for n=133 69.6 (3.0) (65 – 76) Fallers (≥1 fall) vs nonfallers Not reported Up to 12 mont hs if no fall befor e that ip t From sensor worn at the wrist 8m walk at self-selected comfortable speed – Gaitrite mat us Not reported DT1: Listening to a randomised audio sequence for “X” and repeating the letter aloud Not reported DT1: Mental tracking: Backward counting aloud by from 50 No – “combin e both tasks as best as possible” 10/57 (17.5 %) “be as accurate as possible when performi ng the cognitive task and keep walking at all times” 69(52 %) an Nonfallers vs ≥1 validate d fall (while ambula ting during monitor ing interval ) Nonfallers vs ≥1 fall M 76.9(11.9) d Geriatric Hospital inpatients Median (IQR) length of stay: non-fallers 24(23) vs fallers 26.5 (61) MMSE median score =17 for 10 fallers and 24 for 47 non-fallers All able to walk more than 12m without an assistive device Intermittent use of walking aid (n=8) Community-dwellers recruited from flyers and ads; Inclusion criteria: MMSE score ≥24, visual acuity of at least 20/40, with or without corrective lenses Exclusion criteria: diagnosed neurodegenerative disease (e.g., Alzheimer‟s disease) and/or stroke; on psychotropic drugs; 69 (77%) But DT data only for n=34 ep te Kressi g et al., 2007 Assisted living facility resident Mean (SD) MMSE:18.3 (7.2) Ac c Kearn s et al, 2012 cr women) Identifi ed after dischar ge using hospital acciden t‟s databas e betwe een admis sion and disca hrge 12m walk at self-selected comfortable speed – Gaitrite mat Monthl y falls calenda rs? 12 mont hs 12.2m (40 feet- 6.1m walk, turn and 6.1m walk) at self-selected comfortable speedstopwatch DT1: Mental tracking: Reciting alternate letters from the alphabet 12(35 %) ST NF vs fallers (n: 22/12): 0.71(0.20) vs 0.73(0.31) DT1 NF vs fallers (n: 22/12): 0.67(0.19) vs 0.72(0.26) ST NF vs fallers (n: 47/10): 0.75(0.21) vs 0.64(0.14) DT1 NF vs fallers (n: 47/10): 0.73(0.25) vs 0.60(0.17) ST NF vs fallers (n: 64/69): 1.18(0.16) vs 1.14(0.25) DT1 NF vs fallers (n: 63/69): 0.92(0.38) vs 0.94(0.36) Page 42 of 52 Taylor et al., 2012 Community-dwellers recruited through ads, health services, etc Inclusion criteria: having an identified and willing „„person responsible‟‟with at least 3.5 h of face to face contact per week; Cognitive impairment: MMSE < 24, Addenbrooke‟s Cognitive ip t cr us M an 63(46%) Nonfallers vs ≥1 fall "An event in which the participant unintention ally came to rest on the floor or ground, regardless of the cause or the consequen ces of the fall" “loss of balance resulting in landing on the floor or ground or lower level, and including slips or trips” d ≥75 years; 78.0 (nonfallers) 80.0 (fallers) ep te 192 complete d the dual-task paradigm out of 230 (72.2% women) Ac c Nordi n et al, 2010 not speaking and understanding English; moderate to significant impairment with activities of daily living as determined by interview; on cholinesterase inhibitors within the last 12 months; on antidepressants within the last months; on estrogen replacement therapy within the last 12 months Community dwelling recruited through advertisement Inclusion criteria: ability to walk at least 10 m without a walking aid, MMSE score ≥24 ≥60 years; Mean (SD): 81.3(6.8) Multipl e fallers (≥2 falls) vs nonmultipl e fallers (