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http://www.diva-portal.org This is the published version of a paper published in Journal of the American Medical Directors Association. Citation for the original published paper (version of record): Toots, A., Littbrand, H., Holmberg, H., Nordström, P., Lundin-Olsson, L. et al. (2017) Walking aids moderate exercise effects on gait speed in people with dementia: a randomized controlled trial. Journal of the American Medical Directors Association, 18(3): 227-233 https://doi.org/10.1016/j.jamda.2016.09.003 Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. Permanent link to this version: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-127495

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http://www.diva-portal.org

This is the published version of a paper published in Journal of the American Medical DirectorsAssociation.

Citation for the original published paper (version of record):

Toots, A., Littbrand, H., Holmberg, H., Nordström, P., Lundin-Olsson, L. et al. (2017)Walking aids moderate exercise effects on gait speed in people with dementia: a randomizedcontrolled trial.Journal of the American Medical Directors Association, 18(3): 227-233https://doi.org/10.1016/j.jamda.2016.09.003

Access to the published version may require subscription.

N.B. When citing this work, cite the original published paper.

Permanent link to this version:http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-127495

JAMDA 18 (2017) 227e233

JAMDA

journal homepage: www.jamda.com

Original Study

Walking Aids Moderate Exercise Effects on Gait Speed in PeopleWith Dementia: A Randomized Controlled Trial

Annika Toots PTa,b,*, Håkan Littbrand PhD a,b, Henrik Holmberg PhD c,Peter Nordström PhD b, Lillemor Lundin-Olsson PhD a, Yngve Gustafson PhD b,Erik Rosendahl PhD a,b

aDepartment of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, SwedenbDepartment of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, SwedencDepartment of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden

Keywords:Mobility limitationsResidential facilitiesAlzheimer diseaseRehabilitationFrail elderly

This work was supported by the Swedish ReseaK2009-69P-21298-01-4, K2009-69X-21299-01-1, K2099X-22610-01-6); ForteeSwedish Research Council fWelfare (formerly FASeSwedish Council for Working Lnumber 2012-0775) the Vårdal Foundation; the SwediPromobilia Foundation; the Swedish Society of MediFoundation; the King Gustav V and Queen Victoria’s FoEuropean Union Bothnia-Atlantica Program; the Couthe Umeå University Foundation for Medical Resea

http://dx.doi.org/10.1016/j.jamda.2016.09.0031525-8610/� 2016 AMDA e The Society for Post-Acuteorg/licenses/by-nc-nd/4.0/).

a b s t r a c t

Objectives: To investigate the effects of exercise on gait speed, when tested using walking aids andwithout, and whether effects differed according to amount of support in the test.Design: A cluster-randomized controlled trial.Setting: The Umeå Dementia and Exercise (UMDEX) study was set in 16 nursing homes in Umeå, Sweden.Participants: One hundred forty-one women and 45 men (mean age 85 years) with dementia, of whom145 (78%) habitually used walking aids.Intervention: Participants were randomized to the high-intensity functional exercise program or a seatedattention control activity.Measurements: Blinded assessors measured 4-m usual gait speed with walking aids if any gait speed (GS),and without walking aids and with minimum amount of support, at baseline, 4 months (on interventioncompletion), and 7 months.Results: Linear mixed models showed no between-group effect in either gait speed test at 4 or 7 months.In interaction analyses exercise effects differed significantly between participants who walkedunsupported compared with when walking aids or minimum support was used. Positive between-groupexercise effects on gait speed (m/s) were found in subgroups that walked unsupported at 4 and 7 months(GS: 0.07, P ¼ .009 and 0.13, P < .001; and GS test without walking aids: 0.05, P ¼ .011 and 0.07, P ¼ .029,respectively).Conclusions: In people with dementia living in nursing homes exercise had positive effects on gait whentested unsupported compared with when walking aids or minimum support was used. The studysuggests that the use of walking aids in gait speed tests may conceal exercise effects.� 2016 AMDA e The Society for Post-Acute and Long-Term Care Medicine. This is an open access article

under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

In older people gait is associated with functional independence,health, and survival.1e4 In addition, poor gait has been shownto predict incident dementia, predominantly non-Alzheimerdementia compared with Alzheimer disease,5 and to deteriorateconcomitantly with disease severity.6 Although gait is slow among

rch Council (grant numbers09-69P-21298-04-4, K2014-or Health, Working Life andife and Social Research; grantsh Dementia Association; thecine; the Swedish Alzheimerundation of Freemasons; thenty Council of Västerbotten,rch; the Ragnhild and Einar

and Long-Term Care Medicine. Th

residents in nursing homes, where dementia is common, for manyit remains functional7 and still amenable for improvement.8

Interventions to maintain gait to preserve independence andpromote health may, therefore, be particularly important in thispopulation.

LundstrÖm’s Memorial Foundation; and the Erik and Anne-Marie Detlof’sFoundation.

H.L. developed and has received royalties on the weighted belt used in theexercise program. All other authors declare no conflicts of interest.* Address correspondence to Annika Toots, PT, Department of Community

Medicine and Rehabilitation, Geriatric Medicine, Umeå University, S-901 87 Umeå,Sweden.

E-mail address: [email protected] (A. Toots).

is is an open access article under the CC BY-NC-ND license (http://creativecommons.

A. Toots et al. / JAMDA 18 (2017) 227e233228

While exercise appears to improve gait in people with dementiain community settings,9,10 results are inconsistent in nursing homepopulations where severity of physical and cognitive impairments isgreater.11,12 To further evaluate effects of exercise in randomizedcontrolled trials would, therefore, be of value in this setting. Inaddition, many older people with dementia living in nursing homes

Fig. 1. Flow of participants.

use walking aids that can improve gait performance throughalleviating impaired balance or pain.13,14 Subsequently, gait speedmeasured using a walking aid could limit detection of gait deficits,thus, reduce responsiveness of the test.15 Furthermore, in peoplewith dementia the impact may be pronounced given the cognitivedemand of walking aid use.14

SD, standard deviation.

A. Toots et al. / JAMDA 18 (2017) 227e233 229

We have previously reported positive exercise effects on balance inpeople with dementia living in nursing homes.16 With the notion thatleg strength and balance are important components of gait, thehypothesis of this study was therefore that the exercise programwould improve gait speed, and that the use of a walking aid couldconceal the exercise effects because of reduced responsiveness. Theaim was to investigate the effects of a high-intensity functionalexercise program on gait speed in people with dementia living innursing homes, when tested using habitual walking aid if any andwithout walking aids. Further aims were to investigate whethereffects differed according to support in the test, type of dementia, sex,or level of cognitive impairment.

Methods

This study was part of the Umeå Dementia and Exercise Study(UMDEX), a cluster-randomized controlled trial, conducted in nursinghomes inUmeå, Sweden, includinggeneral anddementiaunits, allwithprivate rooms and staff on hand, as well as, units with private apart-ments with access to on-site nursing and care. The Regional EthicsReview Board of Umeå approved the study (2011-205-31M). The studyprotocol (ISRCTN31767087) is published on the ISRCTN registry.

Participants

Residents with a Mini-Mental State Examination (MMSE) score�10,17 a dementia diagnosis,18 age�65 years, dependent on assistancein�1 personal activity of daily living (ADL),19 ability to stand up from achair with armrests with assistance from �1 person, physician’sapproval, and ability to hear and understand spoken Swedish wereincluded. All individuals included in the study gave informed oralconsent to participation, which was confirmed by their next of kin.Age (P ¼ .189) and MMSE score (P ¼ .713) did not differ betweenparticipants included in the study and those who declinedparticipation (n ¼ 55; Figure 1). A larger proportion of men thanwomen declined participation (34% vs 18%; P ¼ .008).

Randomization

Randomization was performed after completion of the enrollmentprocess and baseline assessment to ensure concealed allocation.Clusters (n¼ 36) of 3-8 participants each (who lived in the samewing,unit, or floor) were formed. Two researchers not involved in the studyperformed randomization by drawing lots using sealed opaqueenvelopes.

Sample Size

Sample size was calculated for the main outcome, the Barthel ADLIndex, in the UMDEX study.16 A sample size of 183 participants wererequired to verify significant intervention effects at a statistical powerof 80% at the 4-month follow-up, a significance level of 0.05, 2-sided,and a presumed dropout rate of 10%.

Intervention

The exercise and attention control activities were conducted atnursing homes in small groups (n ¼ 3e8) supervised by 2 physicaltherapists (PTs) and 1 occupational therapist (OT) or OT assistant,respectively. The intervention started October 2011 and lasted4 months (40 sessions in total) and consisted of five 45-minutesessions per 2-week period. When possible, supervised individualsessions were offered when participants were unable to attend agroup session. Participation in activities other than provided by thestudy was not restricted.

Exercise

The exercise intervention was based on the high-intensityfunctional exercise (HIFE) program available from authors anddescribed further elsewhere20,21 (Appendix 1). The HIFE programcomprises 39 functional exercises that aim to improve lower limbstrength, balance, and mobility, and performed in weight-bearingpositions. Exercise intensity aimed to be high and exercises adaptedaccordingly through progressive adjustment of load and base ofsupport, while also taking into account participants’ symptoms andchanges in health and functional status. Participants were supervisedindividually to promote the highest possible exercise intensity, whileensuring their safety.

Attention Control

The OT and OT assistant who took part in the study developedthe attention control activity program. While seated in a group,participants conversed, sang, listened to music or readings, and/orlooked at pictures and objects associated with topics such as wildlifeand current seasons and holidays.

Measurements

PTs and physicians blinded to activity allocation and previous testresults performed all measurements at baseline and follow-ups.Physicians used electronic records of participants’ past medicalhistories, which included brain imaging in most cases, currentpharmaceutical treatment, and assessment results to record dementiatype, depressive disorders, and delirium diagnoses. A specialist ingeriatric medicine reviewed and confirmed these diagnoses accordingto DSM-IV-TR criteria.18

Outcome Measures

Usual gait speed (GS) was measured over 4 m.22 GS mode waschosen based on the results of a previous study in nursing homes thatshowed effects on usual but not on fast gait speed.23 A 4-m distancewas marked along the base of a wall, and a visible target (eg, a chair)placed approximately 2 m beyond it. From a standing still start posi-tion, participants were asked to walk in their usual pace to the visibletarget. Using a digital stopwatch, the time was measured from wheninstructed to start until the participant’s trunk crossed the marking onthe wall. The procedure was repeated twice, and the mean GS time(m/s) calculated. When only 1 GS time was registered, it was includedin the analyses. The habitual walking aid was used in the GS test.

To reduce the support provided by walking aids, a second gaitspeed test without walking aids and with minimum amount ofsupport (GS-noWA) was conducted according to the same testprocedure as outlined above. Participants who used a walking aidperformed the GS-noWA test without the walking aid. Participantswho walked unsupported only performed the GS test, and their timewas carried over to the GS-noWA test. Participants who wereunable to walk without a walking aid were offered a minimumamount of living support. One or 2 testers provided single-sided ordouble-sided support in a standardized manner. The participantplaced their pronated hand(s) over the supinated hand of thetester(s). To reduce the influence on pace, testers were instructed toprovide support only in an upright direction and only by this point ofcontact, with no other contact or support allowed.

When unable to perform a gait speed test, the reason wasregistered and categorized as physical impairment, motivation, othercauses (eg, pain, dizziness, absence from ward), or deceased. In allgait speed tests, at baseline, and 4 and 7 months, the same type of

Table 1Participant Characteristics and Outcome Measures at Baseline

Characteristics Totaln ¼ 186

Exercisen ¼ 93

Controln ¼ 93

Age 85.1 � 7.1 84.4 � 6.2 85.9 � 7.8Female 141 (75.8) 70 (75.3) 71 (76.3)Dementia typeVascular 77 (41.4) 36 (38.7) 41 (44.1)Alzheimer 67 (36.0) 34 (36.6) 33 (35.5)Other 27 (14.5) 15 (16.1) 12 (12.9)Mixed Alzheimer/vascular 15 (8.1) 8 (8.6) 7 (7.5)

Diagnoses and medical conditionsDepressive disorders 107 (57.5) 53 (57.0) 54 (58.1)Delirium previous week 102 (54.8) 48 (51.6) 54 (58.1)Previous stroke 57 (30.6) 33 (35.5) 24 (25.8)Heart failure 56 (30.1) 24 (25.8) 32 (34.4)

Prescription medicationAnalgesics 112 (60.2) 55 (59.1) 57 (61.3)Antidepressants 102 (54.8) 58 (62.4) 44 (47.3)Number of drugs 8.3 � 3.8 8.4 � 4.0 8.2 � 3.7

AssessmentsUsual mobility deviceWheelchair 24 (12.9) 11 (11.8) 13 (14.0)Rollator 117 (62.9) 64 (68.8) 53 (57.0)Stick or crutch 4 (2.2) 1 (1.1) 3 (3.3)Unsupported 41 (22) 17 (18.3) 24 (25.8)

MMSE (0e30)* 14.9 � 3.5 15.4 � 3.4 14.4 � 3.5Barthel ADL index (0e20)* 10.9 � 4.4 10.7 � 4.5 11.0 � 4.4Neuropsychiatric inventory

(0e144)y14.8 � 14.2 15.2 � 15.8 14.4 � 12.6

Outcome measuresGS, m/s, n ¼ 177 0.470 � 0.21 0.467 � 0.20 0.473 � 0.22GS-noWA, m/s, n ¼ 169 0.437 � 0.23 0.421 � 0.23 0.453 � 0.24

GS, gait speed with habitual walking aid if any; GS-noWA, gait speed withoutwalking aid and with minimum support.Values are mean � SD or n (%). Numbers reported after covariates indicate numberof measurements available when values were missing.

*Higher scores indicate better status.yLower scores indicate better status.

A. Toots et al. / JAMDA 18 (2017) 227e233230

walking aid or amount of support was used. The same PT measuredgait speed at baseline and all follow-ups.

Data Analysis

Possible confounders were selected a priori (Appendix 2, Table A1),from which significant imbalances between exercise and attentioncontrol groups and associations (r � 0.3) with changes in outcomemeasures at 4 and 7 months were analyzed using Student t-test or thePearson c2 test, and Pearson correlation coefficients. No variable wasfound to associate with change in outcome measures abovepredefined levels. The variable antidepressant use differed betweengroups (P ¼ .04) and was adjusted for in analyses.

In agreement with the intention-to-treat principle, available datafor each participant were analyzed according to original allocation andregardless of level of attendance. Longitudinal changes in GS andGS-noWA from baseline to 4 and 7 months were analyzed in linearmixed effects models, using interaction terms for activity and timepoint and adjustment for age, sex, and antidepressant use as fixedeffects, and individual and cluster allocation as random effects.Baseline values for outcome measures were included in thedependent variable to avoid loss of data. The least square meanwithin-group difference was estimated from these models.

Subgroup analyses were conducted according to sex, dementiatype, cognitive level, and support in the test by adding interactionterms to adjusted models. Dementia type was dichotomized asAlzheimer or other (non-Alzheimer) dementia.16 Level of cognitiveimpairment was dichotomized based on the median MMSE score of15. Support in the test was dichotomized as unsupported vs anywalking aid or living support in GS and GS-noWA tests, respectively.Further, the difference in effect between exercise and attention controlgroups were investigated in each subgroup using Student t-tests andleast square mean changes from baseline, with less degrees offreedom to obtain conservative P values.

Effect size was calculated by dividing the between-group differ-ence in linear mixed models by the unadjusted pooled standarddeviation of the difference between post- and preintervention values.

To account for possible bias introduced bymissing values, multipleimputation sensitivity analyses were performed. Fifteen imputeddatasets were generated using predictors based on baseline variablesthat were (1) adjustments or outcome variables in the model, (2)associated (r > 0.3) with outcomes, or (3) associated (r > 0.3) withcategorical causes for missing values.24 The multiple imputationmodels were sequentially conducted for each follow-up. Imputationswere constricted dependent on causes for missing values; whencaused by physical impairment, maximum imputed values waslimited to the lowest observed value, while when caused by theparticipants’ being dead no values were imputed.

All analyseswereperformedusing IBMSPSSStatistics forMacintoshversion 21.0 (IBM Corp, Armonk, NY) and R version 3.2.2 (R Core Team,Vienna, Austria) software. All statistical testswere 2-tailed and P valuesof < .05 were considered to be statistically significant.

Results

There were 186 participants (141 women and 45 men) included inthe study (Table 1). One hundred forty-five (78%) used wheelchair orwalking aids. At baseline, 42 participants (23%) performed the GS testunsupportedand99participants (53%) theGS-noWAtest unsupported.Reasons for missing values on the GS test are presented in Figure 1. Inthe GS-noWA test 17, 31, and 44 participants had missing gait speedvalues at baseline, 4 months, and 7 months, respectively, because ofphysical impairment, motivation, or other causes. Adherence over the4-month intervention period was 73% in the exercise group and 70%in attention control group. Strength exercises were performed at

moderate or high intensity (for 76% of attended sessions) and balanceexercises at high intensity (for 75% of attended sessions).16

Outcomes

There were no differences between exercise and activity groupsin either gait speed test at 4 or 7 months (Table 2, Figure 2, A and B).In interaction analyses, exercise effects on gait speed significantlydiffered according to support, with larger effects in participants whowalked unsupported in the GS test at 4 and 7 months and in theGS-noWA test at 7 months (Table 3). The between-group analysesshowed positive effects on gait speed (m/s, 95% confidence interval)in participants who walked unsupported in the exercise group bothat 4 and 7 months (GS: 0.07, 0.020e0.129 and 0.13, 0.070e0.182 andGS-noWA: 0.05, 0.013e0.095 and 0.07, 0.022e0.109, respectively;Figure 2, C and D). In participants who walked with support, therewas no difference between groups at 4 months (GS: 0.03, �0.064 to0.006; GS-noWA: �0.01, �0.065 to 0.049), and whereas at 7 months,the exercise group had negative effects on GS (�0.04, �0.077to �0.002), no difference was observed in GS-noWA (�0.05, �0.116to 0.016; Figure 2, C and D).

Interaction analyses according to sex, dementia type, and cognitivelevel showed no differences in exercise effects at 4 and 7 months ineither gait speed test (Appendix 2, Table A2).

Sensitivity Analyses

When primary analyses were repeated using the multipleimputed data sets the results remained essentially the same(Appendix 2, Table A3).

Table 2Within- and Between-Group Differences From Baseline in GS and GS-noWA

Measures Within-Group Differences Between-Group Differences ICC*

N Exercise, Mean m/s (SE) N Control, Mean m/s (SE) Mean m/s (95% CI) P Value

GS4 months 75 �0.021 (0.015) 78 �0.015 (0.015) �0.006 (�0.047 to 0.035) 0.777 0.087 months 64 �0.031 (0.016) 69 �0.035 (0.015) 0.004 (�0.039 to 0.048) 0.842

GS-noWA4 months 67 0.005 (0.017) 68 �0.022 (0.016) 0.027 (�0.018 to 0.073) 0.242 0.137 months 53 �0.024 (0.018) 57 �0.046 (0.018) 0.023 (�0.027 to 0.072) 0.368

CI, confidence interval; ICC, intracluster correlation coefficient; N, number of participants with complete data; SE, standard error; GS, gait speed with habitual walking aid ifany; GS-noWA, gait speed without walking aid and with minimum support.Values are from linear mixed-effects models adjusted for age, sex, and antidepressant use.

*Based on proportion of variation explained by cluster.

A. Toots et al. / JAMDA 18 (2017) 227e233 231

Additional Analyses

To further explore the absence of exercise effects in participantswho performed the gait speed test with walking aids or minimumsupport, additional analyses on change in the Berg balance scale(BBS)25 was conducted using the same interaction terms for walkingaid use and amount of support and adjustments as describedpreviously. We have previously reported positive exercise effects onthe BBS, which measures balance in functional activities (eg, reachingwhile standing, rising from a chair, transfer between chairs) at4 months.16 The additional interaction analyses showed that thepositive exercise effects on balance (BBS score, 95% confidenceintervals) did not differ according to walking aid use or amount ofsupport in the GS and GS-noWA tests (0.06, �5.7 to 5.8, P ¼ .983 and0.31, �4.5 to 5.2, P ¼ .901, respectively).

Discussion

In this study, where the majority of participants habitually usedwalking aids, the effects of the exercise program on GS appeared to

Fig. 2. Changes in GS and GS-noWA (A and B) and according support in the test (C and D). Vlinear mixed-effects models adjusted for age, sex, and antidepressant use. GS, gait speed wminimum support; ES, effect size; Min, minimum.

differ according to amount of support used in the test. Exerciseseemed to have a positive effect on gait speed in participants whotested unsupported compared with when walking aids or livingsupport was used. The effects of exercise did not differ according tosex, cognitive level, or dementia type.

The positive exercise effects on gait in the subgroups that walkedunsupported are in line with a large randomized controlled trial thatincluded only ambulant people with dementia living in nursinghomes11; although the comparison is limited because walking aid usewas not reported. The study found that a 1-year exercise interventionhad positive effects on gait speed compared with usual care.Considering the reduced social interaction in nursing homes, the extraattention of the intervention may have resulted in larger effect sizeswhile also limiting inferences regarding exercise effects per se.

The absence of positive exercise effects in participants whowalkedwith a walking aid are comparable with a large study in people withdementia living in nursing homes, which showed improvement tobalance while not to gait.12 Furthermore, although the study similarlyto ours had a high proportion of participants who used walking aids,its influence on exercise effects was not analyzed. In accordance with

alues are least square mean change from baseline, with 95% confidence intervals, fromith habitual walking aid if any; GS-noWA, gait speed without walking aid and with

Table 3Within-Group Differences From Baseline in GS and GS-noWA and Differences in Exercise Effects According to Support in the Test

Measures Within-Group Difference Interaction*

N Exercise, Mean m/s (SE) N Control, Mean m/s (SE) Mean m/s (95% CI) P Value

GS4 monthsUnsupported 15 0.025 (0.033) 23 �0.049 (0.027) 0.104 (0.008e0.200) .034With walking aid 60 �0.031 (0.016) 55 �0.002 (0.017)

7 monthsUnsupported 14 0.015 (0.034) 22 �0.111 (0.027) 0.166 (0.068e0.264) .001With walking aid 50 �0.041 (0.028) 47 �0.001 (0.018)

GS-noWA4 monthsUnsupported 42 0.023 (0.021) 46 �0.031 (0.020) 0.038 (�0.032 to 0.156) .199With min support 26 �0.021 (0.026) 22 �0.013 (0.028)

7 monthsUnsupported 32 �0.006 (0.023) 42 �0.072 (0.021) 0.106 (0.013e0.221) .029With min support 21 �0.045 (0.028) 15 0.005 (0.032)

n, number of participants with complete data; Min, minimum; SE, standard error; GS, gait speed with habitual walking aid if any; GS-noWA, gait speed without walking aidand with minimum support.Values are from linear mixed-effects models adjusted for age, sex, and antidepressant use.

*Difference in exercise effect between participants whowalked unsupported compared withwalking aids/minimum support; exercise effect being the difference from baselinein the exercise group minus the difference in the control group. A positive interaction value indicates a greater exercise effect in favor of participants who walked unsupported.

A. Toots et al. / JAMDA 18 (2017) 227e233232

results of a study set in a geriatric inpatient ward, our study suggeststhat when gait speed is tested using walking aids, it may reduce theresponsiveness of the test.15 When gait was tested without walkingaids, and a greater number walked unsupported, positive subgroupeffects persisted. The reduced responsiveness may explain theabsence of positive exercise effects in participants unable to testwithout walking aids or living support. A concealment of effects isfurther supported by results from the interaction analyses on balance,where positive exercise effects were observed irrespective of use ofwalking aid or support while walking.

The result of our studymay be of value both in clinical and researchsettings when interested in best medical practice concerning care ofolder people with dementia living in nursing homes, as well as, wheneffectiveness of rehabilitation is measured in populations wherewalking aid use are common. The exercise effects in participants whowalked unsupported at 4 and 7 months, 0.07 m/s and 0.13 m/s in theGS test and, 0.05m/s and 0.07m/s in the GS-noWA test, seem clinicallymeaningful. In comparison, small and substantial meaningful changesin gait speed has been reported to correspond with 0.05 m/s and0.10 m/s, respectively, in older people with mild to moderate mobilitydisability.26 Walking aids appear to conceal changes over time in gaitspeed; it may be important to measure gait unsupported to fullyunderstand the progression and severity of the impairment and theassociation to health-related outcomes such as falls and survival.

This study has many strengths. The randomized design, anonexercise attention control group, blinded assessors, and arelatively low dropout rate, all contribute to results that may begeneralized to older people with dementia living in nursing homes.This study also has limitations. A floor effect of both gait speed testswas evident because inclusion criteria were comparatively generous.To improve generalization, those unable to perform the test withouttheir usual walking aid were, therefore, offered a standardizedminimum amount of living support in the GS-noWA test; this type ofsupport has not been tested for reliability. Furthermore, someparticipants were still unable to perform the gait speed tests,particularly at the last follow-up. Therefore, the primary analyses wererepeated using multiple imputed data sets, which showed similarresults. Although the sample size was based on power calculations ona different outcome (the Barthel ADL index), it is within recommendedestimates for older people with mobility disability26; however,subgroup analyses may still have limited power and should beinterpreted with caution.

Conclusions

In this study of people with dementia living in nursing homes,where a majority used walking aids, a 4-month high-intensityfunctional exercise program had positive effects on gait inparticipants who tested unsupported compared with when walkingaids or living support was used. The study suggests that the use ofwalking aids in gait speed tests may conceal exercise effects.

Acknowledgments

We would like to express our sincere gratitude to all whocontributed to data collection and implementation of the UMDEXstudy, as well as, the Social Authorities of the Municipality of Umeå,care staff, and participants.

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