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Action Seniors! - secondary falls prevention in community-dwelling senior fallers: study protocol for… Liu-Ambrose, Teresa; Davis, Jennifer C; Hsu, Chun L; Gomez, Caitlin; Vertes, Kelly; Marra, Carlo; Brasher, Penelope M; Dao, Elizabeth; Khan, Karim M; Cook, Wendy; Donaldson, Meghan G; Rhodes, Ryan; Dian, Larry Apr 10, 2015

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STUDY PROTOCOL Open AccessAction Seniors! - secondary falls prevention incommunity-dwelling senior fallers: study protocolled trialsociety’s limited financial resources and the known and increasing burden of falls, there is an urgent need to testTRIALSLiu-Ambrose et al. Trials  (2015) 16:144 DOI 10.1186/s13063-015-0648-7212-2177 Wesbrook Mall, Vancouver, BC V6T 1Z3, CanadaFull list of author information is available at the end of the articlethis feasible intervention which would be eminently ready for roll out.Trial registration: Protocol Registration System: NCT01029171; registered 7 December 2009.Keywords: Otago Exercise Program, Falls, Resistance Training, Executive Functions, Older Adults* Correspondence: Teresa.ambrose@ubc.ca1Aging, Mobility, and Cognitive Neuroscience Laboratory, DjavadMowafaghian Centre for Brain Health, University of British Columbia,applying the intervention to a targeted high-risk populaTeresa Liu-Ambrose1*, Jennifer C Davis1,2, Chun Liang Hsu1, Caitlin Gomez1, Kelly Vertes1, Carlo Marra3,Penelope M Brasher2, Elizabeth Dao1, Karim M Khan4, Wendy Cook5, Meghan G Donaldson2, Ryan Rhodes7and Larry Dian6AbstractBackground: Falls are a ‘geriatric giant’ and are the third leading cause of chronic disability worldwide. About 30%of community-dwellers over the age of 65 experience one or more falls every year leading to significant risk forhospitalization, institutionalization, and even death. As the proportion of older adults increases, falls will place anincreasing demand and cost on the health care system. Exercise can effectively and efficiently reduce falls. Specifically,the Otago Exercise Program has demonstrated benefit and cost-effectiveness for the primary prevention of falls in fourrandomized trials of community-dwelling seniors. Although evidence is mounting, few studies have evaluated exercisefor secondary falls prevention (that is, preventing falls among those with a significant history of falls). Hence, wepropose a randomized controlled trial powered for falls that will, for the first time, assess the efficacy and efficiency ofthe Otago Exercise Program for secondary falls prevention.Methods/Design: A randomized controlled trial among 344 community-dwelling seniors aged 70 years and olderwho attend a falls prevention clinic to assess the efficacy and the cost-effectiveness of a 12-month Otago ExerciseProgram intervention as a secondary falls prevention strategy. Participants randomized to the control group willcontinue to behave as they did prior to study enrolment. The economic evaluation will examine the incrementalcosts and benefits generated by using the Otago Exercise Program intervention versus the control.Discussion: The burden of falls is significant. The challenge is to make a difference – to discover effective, ideallycost-effective, interventions that prevent injurious falls that can be readily translated to the population. Our proposal isvery practical – the exercise program requires minimal equipment, the physical therapist expertise is widely available,and seniors in Canada and elsewhere have adopted the program and complied with it. Our innovation includestion, aiming to provide the best value for money. Givenfor a randomized control© 2015 Liu-Ambrose et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (, which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly credited. The Creative Commons Public DomainDedication waiver ( applies to the data made available in this article,unless otherwise stated.Liu-Ambrose et al. Trials  (2015) 16:144 Page 2 of 9BackgroundFalls are a common geriatric syndrome [1] and are the thirdleading cause of chronic disability worldwide [2]. Falls im-pose significant risk for hospitalization, institutionalization,and even death [3-5]. About 30% of community-dwellersover the age of 65 experience one or more falls every year[6], with half of these seniors experiencing recurrent falls.With the proportion of older adults increasing, falls willcontinue to place an increasing health and economic bur-den on the public health system.Exercise can effectively reduce falls. Specifically, NewZealand researchers designed a physical therapist-delivered,progressive home-based strength and balance training pro-gram tailored for seniors [7-11]. This intervention – theOtago Exercise Program (OEP) – has demonstrated benefitin four randomized trials of community-dwelling seniorsselected based on age alone (that is, ≥ 80 years old) [7-11].Only one of these four trials designated falls as the primaryoutcome [12] while the others focused on measures of fallsrisk. Hence, the OEP qualifies as primary falls prevention(that is, preventing falls among those without a history offalls). The Cochrane Collaboration [13] explicitly identifiesthe OEP as the exercise training program with the strongestevidence for falls prevention. Although the OEP is the exer-cise training program with the strongest evidence for pri-mary falls prevention [13], no randomized controlled trial(RCT) powered for falls has evaluated the efficacy of theOEP as a secondary falls prevention (that is, preventing fallsamong those with a history of falls) strategy. Hence, a rigor-ously designed RCT with falls as the primary outcome is anessential next step to determine the role of OEP in prevent-ing falls among senior men and women with a significanthistory of falls. Previous research has demonstrated that thebest value for money of various falls prevention strategiescomes from targeting high-risk groups [14].Improved physiological function is the generally ac-cepted mechanism underlying the effectiveness of theOEP in reducing falls [8]. However, in a meta-analysisof four OEP randomized trials, falls were significantlyreduced by 35% while postural sway significantly im-proved by only 9% and there was no significant im-provement in knee extension strength [11]. Hence, theOEP may reduce falls via mechanisms other than im-proved physiological function. Specifically, we have dem-onstrated proof-of-concept data suggesting that improvedcognitive function may be a very important mechanism bywhich the OEP reduces falls [15].Within the multiple domains of cognitive function, re-duced executive functions are associated with falls [16-20].Executive functions are higher order cognitive processesthat control, integrate, organize, and maintain other cogni-tive abilities [21]. Executive functions decline substantiallywith aging [22]. Importantly, reduced executive functionsare prevalent among healthy, community-dwelling seniorswith intact global cognitive function (that is, Mini-MentalState Examination (MMSE) score ≥24/30) [23,24]. Thisis not surprising given that many of the pathologicalchanges (for example, white matter lesions) associatedwith reduced executive functions are prevalent butclinically silent [25]. Our proof-of-concept study pro-vided preliminary evidence that the OEP may improveexecutive functions in senior fallers [15]. Given theassociation between executive functions, exercise, andfalls, we hypothesize that improved executive functionsmay be an important mechanism by which exercise re-duces falls. However, this hypothesis is yet to be tested.Furthermore, our proof-of-concept study did not havethe sample size to explore whether the observed changein cognitive function was a mediator of the benefit ofthe OEP.Thus, we propose a 12-month RCT among community-dwelling seniors aged 70 years and older who attend asecondary falls prevention clinic to assess the efficacy andthe cost-effectiveness of the OEP as a secondary falls pre-vention strategy. Further, we aim to explore the relativeimportance of both physiological and cognitive factorsto falls reduction. Given the immense health and finan-cial burden imposed by falls, our proposed RCT couldhave significant impact on the health of Canadian seniorsand the Canadian health care system.MethodsDesignWe propose a RCT of 344 community-dwelling seniorwith a history of falls (that is, one or more falls in the past12 months), aged 70 and older. Participant randomized tothe OEP intervention group will receive the interventionfor 12-months. There will be three measurement sessionswith monthly monitoring (Figure 1).SettingAll participants will be recruited from the Falls PreventionClinic at Vancouver General Hospital ( participants attending the Falls Prevention Clinic havesustained one or more falls in the past 12 months. Referralsto the Falls Prevention Clinic are from health care profes-sionals (for example, physicians) for those who soughtmedical attention for their fall. Patients who attend theFalls Prevention Clinic receive falls risk factor assess-ment followed by a comprehensive geriatric assessment.The Falls Prevention Clinic care pathway is based onthe American Geriatrics Society/British Geriatrics Society/American Academy of Orthopedic Surgeons Falls Pre-vention Guidelines [26] (which is hereafter referred toas “standard of care”).Liu-Ambrose et al. Trials  (2015) 16:144 Page 3 of 93Charts from the clinic will be reviewed on a weeklybasis to identify eligible participants. Those who appeareligible based on detailed chart review will be mailed aninformation package and asked to call a research assist-ant if they are interested in participating in the study.When phone contact generates a person’s agreement toparticipate, a research assistant will follow-up with a homevisit. During this home visit, the consent form will bereviewed. Once written informed consent is obtained, theresearch assistant will complete the baseline assessment.Upon completion of the assessment, the research assist-ant who will remain blinded to group allocation willcontact the research coordinator who will access thecentral randomization service to reveal the treatmentallocation.EligibilityInclusion criteria1. Adults ≥70 years referred by a medical professionalto the Falls Prevention Clinic as a result of seekingFigure 1 Overview of the flow of participants through the Action Seniomedical attention for a non-syncopal fall in theprevious 12 months2. Understands, speaks, and reads English proficiently3. MMSE [27] score ≥24/304. A Physiological Profile Assessment (PPA; Prince ofWales Medical Research Institute, Sydney, Australia)[28] score of at least 1.0 standard deviation aboveage-normative valueorTimed Up and Go (TUG) test [29] performance ofgreater than 15 secondsorone additional non-syncopal fall in the previous12 months5. Expected to live greater than12 months (based onthe geriatricians’ expert opinion);6. Living in the Greater Vancouver area7. Community-dwelling (that is, not residing in a nursinghome, extended care unit, or assisted-care facility)8. Able to walk 3 meters with or without an assistive device9. Able to provide written informed consentrs! trial.Liu-Ambrose et al. Trials  (2015) 16:144 Page 4 of 9Exclusion criteria1. Previously diagnosed with or suspected (by thegeriatrician) to have neurodegenerative disease(for example. Parkinson’s disease)2. Previously diagnosed with or suspected (by thegeriatrician) to have dementia (of any type)3. Had a stroke4. Have a history indicative of carotid sinus sensitivity(that is, syncopal falls)Ethical approval has been obtained from the VancouverCoastal Health Research Institute (V10-70171, 11 May2004) and the University of British Columbia’s ClinicalResearch Ethics Board (H04-70171, 11 May 2004).Power calculationThe primary outcome is self-reported number of fallsover the 12-month follow-up period. The sample sizecalculation employs a negative binomial regressionmodel [30] to account for the overdispersion typical offalls data. Assuming an average fall rate in the controlgroup of 1.0 falls per year, an average follow-up of0.9 years and an overdispersion parameter, φ, of 1.6, werequire 163 seniors per group to have 80% power to de-tect a 35% relative reduction in fall rate (that is, 1.0versus 0.65 falls per year). To accommodate a completeloss to follow-up rate of 5% (that is, no fall diariesreturned) we will recruit a total of 344 seniors (that is,172 per group). The estimate of the control fall ratecomes from the pooled analysis of four trials in a similarpopulation [11]. The estimate of the overdispersionparameter comes from analysis of the data in Table twoof Shumway-Cook [31] which yields φ = 1.6. The esti-mate for the average length of follow-up is based on ourprevious proof-of-concept study conducted locally in thesame patient population in Greater Vancouver [15,32].Only one of 74 participants returned no fall diaries soour estimate of a 5% complete loss to follow-up rate isconservative [32].MeasurementsBaseline measurements will be obtained prior torandomization. There will be three measurement sessions:baseline, 6 months, and 12 months.Falls prevention clinic visitThe measurements listed below are acquired as part ofthe Falls Prevention Clinic visit and will be collected asthe participants' baseline values upon informed consent.Anthropometry Standing height is measured as stretchstature to 0.1 cm per standard protocol. Weight will bemeasured to 0.1 kg on a calibrated digital scale.Geriatrician examination All patients undergo a com-prehensive geriatrician assessment based on the AmericanGeriatrics Society/British Geriatrics Society/AmericanAcademy of Orthopedic Surgeons Falls Prevention Guide-lines [26].General health, falls history, and socioeconomic statusGeneral health, falls history in the last 6 months [33], andsocioeconomic status are ascertained by questionnaires.Global cognitive function Global cognitive function isassessed using both the MMSE [27] and the MontrealCognitive Assessment (MoCA) [34]. The MoCA is a brief30-point screening tool for mild cognitive impairment[34] with high sensitivity and specificity. Specifically, it ismore sensitive than the MMSE in detecting mild cognitiveimpairment. Using a cut-off score of 26, the MMSE had asensitivity of 18%, whereas the MoCA detected 90% ofindividuals with mild cognitive impairment [34].Balance and mobility General balance and mobility isassessed with the: 1) Short Physical Performance Battery[35]; and 2) the TUG test [29]. For the Short PhysicalPerformance Battery, participants are assessed on perfor-mances of standing balance, walking, and sit-to-stand. Eachcomponent is rated out of four points, for a maximum of12 points. Poor performance on this scale predicts subse-quent disability [35]. For the TUG test, participants areinstructed to rise from a standard chair, walk a distance of3 meters, turn, walk back to the chair and sit down. ATUG performance time of ≥13.5 seconds correctly classi-fied persons as fallers in 90% of cases [36].Physiological falls risk We use the PPA [28] to assessphysiological falls risk. The PPA is a valid and reliabletool for falls risk assessment. Based on the performanceof five physiological domains (postural sway, hand reactiontime, quadriceps strength, proprioception, and edge con-trast sensitivity), the PPA computes a falls risk score foreach individual and this measure has a 75% predictiveaccuracy for falls in older people [28]. A PPA z-score of0 to 1 indicates mild risk, 1 to 2 indicates moderaterisk, 2 to 3 indicates high risk, and 3 and above indi-cates marked risk [37].Mood We use the 15-item Geriatric Depression Scale[38,39] to screen for depression. The Geriatric DepressionScale specifically assesses for depressed mood in olderpeople and a score of 5 and greater indicates depres-sion [39].Co-morbidity The Functional Co-morbidity Index wascalculated to estimate the degree of co-morbidity associ-ated with physical functioning [40].Liu-Ambrose et al. Trials  (2015) 16:144 Page 5 of 9Instrumental Activities of Daily Living scale The Law-ton and Brody [41] Instrumental Activities of Daily LivingScale screens for impaired instrumental activities of dailyliving. This scale subjectively assesses ability to telephone,shop, prepare food, housekeep, do laundry, handle fi-nances, be responsible for taking medication, and deter-mining mode of transportation.Baseline home visitThe following additional measures will be acquired duringthe home visit when written consent is obtained. Themaximum time lag between the baseline Falls PreventionClinic visit and the home visit is 1 month.Falls-related self-efficacy Falls-related self-efficacy willbe assessed by the Activities-Specific Balance Confidence(ABC) Scale. The 16-item ABC Scale [42] assesses falls-related self-efficacy with each item rated from 0% (noconfidence) to 100% (complete confidence). The ABCScale score is correlated with other measures of self-efficacy, distinguishes between individuals of low and highmobility, and corresponds with balance performancemeasures [43,44].Physical activity level Current physical activity levelwill be assessed by the valid and reliable Physical ActivitiesScale for the Elderly questionnaire [45,46]. This 12-itemscale measures the average number of hours per day spentparticipating in leisure, household, and occupational phys-ical activities over the previous 7-day period.Executive functions There is no unitary executivefunction – rather, there are distinct processes. Thus,no single measure of executive function can adequatelytap the construct in its entirety. Within the context of ourproposal, we refer to work by Miyake and colleagues [47]who identified three key executive processes: 1) set shift-ing; 2) updating (or working memory); and 3) selectiveattention and conflict resolution (or response inhibition).Set shifting requires one to go back and forth betweenmultiple tasks or mental sets [47]. Updating involves mon-itoring incoming information for relevance to the task athand and then appropriately updating the informationalcontent by replacing old, no longer relevant informationwith new incoming information. Conflict resolutioninvolves deliberately inhibiting dominant, automatic, orprepotent responses. We will assess: 1) set shifting usingthe Trail Making Test (Part A and B) [48]; 2) updating(that is, working memory) using the verbal digits forwardand backward test [49]; and 3) response inhibition usingthe Stroop Colour-Word Test [50]. These standardizedneuropsychological tests are sensitive to age- [48,51]and intervention-related changes [52-56]. Informationprocessing speed will be indexed using the Digit SymbolSubstitution Test [57]. For this task, participants are firstpresented with a series of numbers (1 to 9) and their cor-responding symbols. They are asked to draw the correctsymbol for any digit placed randomly in pre-defined seriesin 60 seconds. A higher number of correct answers inthis time period indicates better executive functions andprocessing speed.Verbal fluency Defined as the rate at which an individ-ual can generate words, verbal fluency will be assessedusing both the FAS test (which assesses phonemic verbalfluency) and the animal naming test (which assessessemantic verbal fluency) [48]. For the FAS verbal fluencytest, participants will be asked to verbally generate asmany words (excluding proper names) as they can start-ing with the letters “F”, “A” and “S”, each in 60 seconds[48]. The total number of words generated for all threeletters will be used as the measure of performance. Forthe animal naming test, participants will be asked togenerate a list of animal names in 60 seconds [48].Health-related quality of life We will evaluate health-related quality of life using Euro-Qol-5D three level(EQ-5D-3 L) [58]. The EQ-5D ascertains health statusaccording to the following domains: mobility, self-care,usual activities, pain, and anxiety/depression. We willcalculate quality-adjusted life years using the weightingsfrom each instrument to compare differences in theincremental cost-effectiveness ratios.Monthly measurementThe following measures will be collected monthly bytelephone: 1) current physical activity level as assessed bythe Physical Activities Scale for the Elderly questionnaire;and 2) health-related quality of life as assessed by theShort Form 6D [59], EuroQol EQ-5D-3 L [58], and HealthUtilities Index Mark 3 [60]. Strategies to promote adher-ence to the OEP exercises during these monthly phonecalls will also occur.Through monthly calendars and diaries, participants willbe asked to provide the following information: 1) falls andadherence to the OEP (ascertainment of falls and ad-herence to the OEP will be documented on monthlycalendars); and 2) health care resource utilization andcosts (participants will complete monthly health careresource use diaries over the 12-month study period).RandomizationParticipants will be randomly assigned (1:1) to either theOEP (plus standard of care) group or the standard of care(control) group. The randomization sequence will bestratified by: 1) sex, as falls rate is different betweenmen and women; and 2) geriatrician (LD and WC), asstandard of care delivery may differ between physicians.Liu-Ambrose et al. Trials  (2015) 16:144 Page 6 of 9Permuted blocks of varying size (for example, 2,4,6)will be employed. To ensure concealment of thetreatment allocation, the randomization sequences will begenerated and held by a central Internet randomizationservice.Planned trial interventionsOtago Exercise Program interventionThe OEP is an individualized home-based balanceand strength retraining program [8,61]. It consists ofthe following strengthening exercises: knee extensor(4 levels), knee flexor (4 levels), hip abductor (4 levels),ankle plantarflexors (2 levels), and ankle dorsiflexors(2 levels). The balance retraining exercises consist ofthe following: knee bends (4 levels), backwards walking(2 levels), walking and turning around (2 levels),sideways walking (2 levels), tandem stance (2 levels),tandem walk (2 levels), one leg stand (3 levels), heelwalking (2 levels), toe walking (2 levels), heel toe walkingbackwards (1 level), and sit to stand (4 levels).Licensed physical therapists will deliver the OEP aftera standard training session with the research team. Foreach OEP participant, a physical therapist will visit thehome and prescribe a set of suitable exercises from theOEP manual. The same physical therapist will returnbi-weekly three additional times to make progressiveadjustments to the exercise protocol according to theOEP manual. Each of these four visits in the first2 months will take approximately 1 hour. The physicaltherapist’s fifth visit will occur 6 months after the initialvisit. During this last visit, the physical therapist willcheck that the OEP exercises are being done correctlyand will also encourage the participant to continue withthe exercise program. Overall, the participant is askedto perform the OEP balance and strength retrainingexercises three times per week (approximately 30 minutes).In addition to the OEP manual, which contains a pictureand description of each exercise, each participant will beprovided with an adjustable cuff weight (in 0.9 kgincrements; range = 0.9 to 9 kg) to be used with theOEP strength training exercises. Based on data fromour proof-of-concept study [15], the OEP is safe forour target population; only 2 of the 36 OEP participantsreported low back pain as adverse events.Standard of careParticipants randomized to “standard of care” they receivestandard of care – visits with a geriatrician.Adverse events monitoringA physician and a statistician external to the daily activ-ities of this study will review and compile a report for alladverse events reported in the study on a monthlybasis. They will stop the study if the adverse event datademonstrate any hazards of the intervention (for example,increased falls or fracture) based on the monthly report.Statistical analysesOur primary, secondary, and tertiary analyses will followthe intention-to-treat principle (that is, all individuals willbe analyzed according to their group allocation regardlessof compliance).Primary outcomeThe rate of falls (the primary outcome) will be comparedbetween the two groups using a negative binomial re-gression model. The treatment assignment and stratifica-tion factors will be included in the model as covariates.Point and interval estimates for the rate ratio will bedetermined.Secondary outcomesWe will conduct exploratory analyses on the secondaryoutcomes (PPA, TUG test and Short Performance PhysicalBattery). Given that a potential source of bias in this trialwill result from patients being unblinded to their groupallocation, group will be controlled for in all secondaryanalyses.Economic evaluationOur economic evaluation will examine the incremen-tal costs and benefits generated by using the OEPintervention versus standard of care. The outcome ofour cost effectiveness analysis is the incrementalcost-effective ratio (ICER). By definition, an ICER isthe difference between the mean costs of providingthe competing interventions divided by the differ-ence in effectiveness, where ICER = Δcost/Δeffect[62]. Both a cost-effectiveness analysis and a costutility analysis will be performed. Based on the pri-mary outcome of the RCT, we will determine theincremental cost of the OEP intervention per fallavoided, relative to standard treatment. We will alsoconduct a cost-utility analysis. In a cost-utility ana-lysis, the primary outcome is the quality-adjusted lifeyears. These are calculated based on the quality oflife of a patient (measured using health utilities) in agiven health state and the time spent in that healthstate. An important aspect of economic evaluationsconducted alongside an RCT is how to deal withmissing data due to attrition. We will follow recom-mendations by Oostenbrick and colleagues [63] andBriggs and colleagues [64], and the InternationalSociety for Pharmacoeconomics and Outcomes Research[65], in dealing with missing cost and effectivenessdata. We will use a combination of imputation andbootstrapping to quantify uncertainty due to missingvalues.Liu-Ambrose et al. Trials  (2015) 16:144 Page 7 of 9Mediation analysisWe will use path analysis – a special case of structuralequation modeling where all variables are observed –to investigate how physiological function and cognitivefunction mediate the effect of the intervention onthe primary outcome (that is, falls). Using Mplus 5.1( we will fit a negative binomialregression model that includes one independent variableand mediator variables.DiscussionOur interdisciplinary research team will use a multi-pronged approach to explore the utility of OEP amongseniors at high risk of future falls. The proposed trial mayhave important public health, economic, and mechanisticimplications.Public healthThe simple and proven exercise program (that is, theOEP) has already been implemented nationally inNew Zealand. Therefore, if our study demonstrates theOEP is an efficacious and efficient (that is, cost-effective)secondary falls prevention program, our findings couldbe rolled out immediately by policy makers.EconomicThe parallel economic evaluation is particularly importantbecause, if the intervention proved to be cost-effectivecompared with standard of care, it would provide a strongargument for the OEP in the target population even at atime of fiscal restraint. We highlight that this intervention,the OEP, already has manuals, websites, and educationalmaterial ready for a ‘turn-key’ operation.MechanisticBetter understanding of the primary mechanisms under-lying the OEP (that is, our tertiary research objective)would increase our capacity to refine and developnovel interventions for secondary falls prevention forthe aging population. If improved executive functionsprove to play a significant role in falls reduction, itwould be a major contribution to knowledge in thisfield.Trial statusAs of 1 December 2014 we have obtained ethical ap-proval, have registered the trial and we have success-fully recruited 227 participants. We will aim tocomplete recruitment by 2017. One hundred and fiftyfour patients have completed 6-month follow-up, 133have completed 12-month follow-up and 26 partici-pants have dropped out. The median number of par-ticipation days for individuals who dropped out of thestudy was 103.5.AbbreviationsABC: Activities-Specific Balance Confidence; EQ-5D-3L: Euro-Qol 5D three level version;ICER: Incremental cost-effective ratio; MMSE: Mini-Mental State Examination;MoCA: Montreal Cognitive Assessment; OEP: Otago Exercise Program; PPA: PhysiologicalProfile Assessment; RCT: Randomized controlled trial; TUG: Timed Up and Go.Competing interestsThe authors declare that they have no competing interests.Authors’ contributionsTLA wrote the grant application that was funded by the CanadianInstitute for Health Research and jointly drafted the Action Seniors! Protocol.JCD contributed to writing the grant application that was funded by theCanadian Institute for Health Research and jointly drafted the Action Seniors!Protocol. CLH, CG, KV, and ED are part of the Action Seniors! Research teamand critically reviewed the manuscript. CM and PMB contributed to writingthe grant application that was funded by the Canadian Institute for HealthResearch and critically reviewed the Action Seniors! Protocol. WC criticallyreviewed the grant application that was funded by the Canadian Institutefor Health Research and critically reviewed the Action Seniors! Protocol.KMK contributed to writing the grant application that was funded by theCanadian Institute for Health Research. MGD and RR critically reviewed thegrant application that was funded by the Canadian Institute for HealthResearch. LD is the geriatrician at the Falls Prevention Clinic and part ofthe Action Seniors! Research team. LD critically reviewed the manuscript.The grant application formed the bases for the manuscript. All authors haveread and approved the final manuscript.AcknowledgementsThis study is funded by the Canadian Institute for Health Research. TLAis a Canada Research Chair in Physical Activity, Mobility, and CognitiveNeuroscience, a Michael Smith Foundation for Health Research (MSFHR)Scholar, a Canadian Institutes of Health Research (CIHR) New Investigator,and a Heart and Stroke Foundation of Canada’s Henry JM Barnett’sScholarship recipient. JCD was funded by a CIHR and MSFHR PostdoctoralFellowship. ED is funded by a CIHR Doctoral Award - Frederick Banting andCharles Best Canada Graduate Scholarship. CLH is funded by a PhD AlzheimerSociety Research Program Award. These funding agencies did not play a rolein study design. We obtained approval from UBC Clinical Ethics Review Board.Author details1Aging, Mobility, and Cognitive Neuroscience Laboratory, DjavadMowafaghian Centre for Brain Health, University of British Columbia,212-2177 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada. 2Centre for ClinicalEpidemiology and Evaluation, Vancouver Coastal Health Research Institute &University of British Columbia, 7th Floor, 828 West 10th Avenue, ResearchPavilion, Vancouver, BC V5Z 1M9, Canada. 3School of Pharmacy, MemorialUniversity of Newfoundland, Health Sciences Centre, St. John’s, NL A1B 3V6,Canada. 4Centre for Hip Health and Mobility, Vancouver Coastal HealthResearch Institute & University of British Columbia, 2635 Laurel St, Vancouver,BC V5Z 1M9, Canada. 5St Paul’s Hospital, University of British Columbia, 1081Burrard Street, Vancouver, BC V6Z 1Y6, Canada. 6Vancouver Coastal HealthResearch Institute, Room 3665, 910 West 10th Avenue, Vancouver, BC V5Z1M9, Canada. 7Behavioural Medicine (BMED) Lab, School of Exercise Science,Physical and Health Education, University of Victoria, 3800 Finnerty Road,Victoria, BC V8P 5C2, Canada.Received: 15 December 2014 Accepted: 12 March 2015References1. 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Value Health. 2005;8:521–33.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionLiu-Ambrose et al. Trials  (2015) 16:144 Page 9 of 9Submit your manuscript at


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