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Mobile Health (mhealth) (2748) Web-based and Mobile Health Interventions (3092)

Published on in Vol 15, No 8 (2013): August

Tablet-Based Strength-Balance Training to Motivate and Improve Adherence to Exercise in Independently Living Older People: A Phase II Preclinical Exploratory Trial

Tablet-Based Strength-Balance Training to Motivate and Improve Adherence to Exercise in Independently Living Older People: A Phase II Preclinical Exploratory Trial

Tablet-Based Strength-Balance Training to Motivate and Improve Adherence to Exercise in Independently Living Older People: A Phase II Preclinical Exploratory Trial

Authors of this article:

Patrícia Silveira1 ;   Rolf van de Langenberg2 ;   Eva van het Reve2 ;   Florian Daniel1 ;   Fabio Casati1 ;   Eling D de Bruin2
Article Authors Cited by (100) Tweetations (13) Metrics

    Original Paper

    1University of Trento, Department of Information Engineering and Computer Science, Trento, Italy

    2Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland

    *all authors contributed equally

    Corresponding Author:

    Patrícia Silveira, PhD

    University of Trento

    Department of Information Engineering and Computer Science

    Via Sommarive, 14-Povo

    Trento, 38123

    Italy

    Phone: 39 0461 28 20 93

    Fax:39 0461 28 20 93

    Email: silveira@disi.unitn.it


    Background: Reaction time, coordination, and cognition performance typically diminish in older adults, which may lead to gait impairments, falls, and injuries. Regular strength–balance exercises are highly recommended to reduce this problem and to improve health, well-being, and independence in old age. However, many older people face a lack of motivation in addition to other strong barriers to exercise. We developed ActiveLifestyle, an information technology (IT)-based system for active and healthy aging aiming at improving balance and strength. ActiveLifestyle is a training app that runs on a tablet and assists, monitors, and motivates older people to follow personalized training plans autonomously at home.

    Objective: The objectives were to (1) investigate which IT-mediated motivation strategies increase adherence to physical exercise training plans in older people, (2) assess the impact of ActiveLifestyle on physical activity behavior change, and (3) demonstrate the effectiveness of the ActiveLifestyle training to improve gait speed.

    Methods: A total of 44 older adults followed personalized, 12-week strength and balance training plans. All participants performed the exercises autonomously at home. Questionnaires were used to assess the technological familiarity and stage of behavior change, as well as the effectiveness of the motivation instruments adopted by ActiveLifestyle. Adherence to the exercise plan was evaluated using performance data collected by the app and through information given by the participants during the study. Pretests and posttests were performed to evaluate gait speed of the participants before and after the study.

    Results: Participants were 75 years (SD 6), predominantly female (64%), held a trade or professional diploma (54%), and their past profession was in a sitting position (43%). Of the 44 participants who enrolled, 33 (75%) completed the study. The app proved to assist and motivate independently living and healthy older adults to autonomously perform strength–balance exercises (median 6 on a 7-point Likert scale). Social motivation strategies proved more effective than individual strategies to stimulate the participants to comply with the training plan, as well as to change their behavior permanently toward a more physically active lifestyle. The exercises were effective to improve preferred and fast gait speed.

    Conclusions: ActiveLifestyle assisted and motivated independently living and healthy older people to autonomously perform strength–balance exercises over 12 weeks and had low dropout rates. The social motivation strategies were more effective to stimulate the participants to comply with the training plan and remain on the intervention. The adoption of assistive technology devices for physical intervention tends to motivate and retain older people exercising for longer periods of time.

    J Med Internet Res 2013;15(8):e159

    doi:10.2196/jmir.2579

    Keywords

    motivation; exercises; aged; tablet; mobility; delivery of health care 


    Background

    The primary goal of public health care is to increase the number of years of good health and maintain independence and quality of life as long as possible. Healthy aging is characterized by the avoidance of disease and disability, the maintenance of high physical and cognitive function, and sustained engagement in social and productive activities. These 3 components together define successful aging [1].

    An important part of successful aging is maximization of physical performance. The ability to fully participate in productive and recreational activities of daily life may be affected when the capacity to easily perform common physical functions decreases [1]. Thus, health status is an important indicator of quality of life among older people [2,3]. It has been demonstrated that components of health-related fitness and functional performance or serious, chronic conditions and diseases that directly influence the components of fitness and performance are related to perceived health among middle-aged and older adults [3-5].

    Regular physical activity or exercise substantially prevents the development and progression of most chronic degenerative diseases [6-8], is of benefit to frail and older persons, and is the only therapy found to simultaneously improve sarcopenia, physical function, cognitive performance, and mood in older adults [9]. For older people, a sedentary lifestyle also increases the risk of falls, whereas physically active older people have a reduced risk of falls with injuries [10-12]. An important marker for improvements in physical function that influences health and survival is gait speed [13]. In summary, to increase older adults’ quality of life and fitness, we need to encourage them to become or stay physically active [14-15] and increase their fitness through training.

    The objective of this research is to run a phase II study [16] with a tablet app called ActiveLifestyle [17], an app for the autonomous strength-balance physical training for independently living older adults. We aimed to investigate (1) which information technology (IT)-mediated motivation strategies increased adherence to physical exercise training plans in older people, (2) whether these strategies could induce physical activity behavior change, and (3) the effectiveness of ActiveLifestyle training to improve gait speed.

    Related Work

    Home environmental interventions to prevent functional decline seem to be effective [18] and are preferred by older people (ie, instead of leaving their houses to exercise) [19]. Interventions with integrated assistive technology devices have, in this context, the potential to further help in overcoming some of the barriers to start training [20] and maintaining physical independence for independently living older people [21]. Recently developed innovative ideas designed to alter clinical practice in sports were based on the development of tablet apps for prevention, for instance [22]. Tablet and smartphone software apps specifically designed for health purposes are, in general, enthusiastically adopted as a means of delivering self-managed health interventions [23-25]. However, such tablet-based interventions are often plagued by high attrition rates and varying levels of user adherence [24,25]. Furthermore, the effectiveness of tablet-based health intervention approaches has not yet been demonstrated in older people.

    From a pilot study, we knew it is feasible to use assistive technology devices in an older population with the aim of encouraging performance of physical exercise [20]. The short-duration pilot did not focus on aspects of physical functioning, but indicated that the app could be improved by explicitly considering additional motivational strategies. It is well known that motivation strategies affect adherence to health interventions [26]; however, only a few solutions explore different motivation techniques to stimulate regular physical activity [26-28]. Most of these solutions have the drawback that they do not specifically focus on older people. Albaina et al [29] presented a user-friendly software interface running on a small touchscreen display to motivate older adults to walk. The authors used a graphical representation of a flower to motivate and assist seniors to monitor their daily amount of steps collected by pedometers through this simple metaphor of their performance. To the best of our knowledge, there is not another software app dedicated to strength-balance training plans for older people.


    ActiveLifestyle

    ActiveLifestyle is a software app for active aging, aimed at assisting, monitoring, and motivating older people during autonomous home-based physical workouts [20,30,31]. The software takes usability aspects into account, to ensure that older users can use it independently and it adopts a set of motivation strategies to stimulate users to exercise regularly. A video of the app is available on YouTube [32], and the app can be downloaded from the Apple App Store [17].

    Three levels of strength-balance training plans are supported in the app: beginner, intermediate, and expert. In all levels, the balance training should be done 5 days per week. Sessions are composed of 3 exercises, in which the trainees repeatedly (1-3 times) hold a certain position for several seconds (15-30 sec). Each level has different exercises, allowing progression as the person advances through the levels (eg, at the intermediate level the older person must perform the exercises while standing on a towel; at the expert level the exercise must be performed with the eyes closed). Strength training has 3 levels and should be done twice a week; starting with 6 warm-up exercises, then 10 strength and 2 stretching exercises. A minimum number of sets (1-3) and repetitions (12-30) are available for each exercise. Some exercises require the use of weights (2-6 kg). The required effort of the exercises increases according to the level (eg, the beginner level does not require weights; the intermediate level requires ankle weights and performance in the sitting position; the expert level requires weights and exercises performed in standing position). The strength-balance training follows best practices recommendations and training principles (eg, it is progressive in nature) [33,34]. Figure 1 illustrates some exercises supported by ActiveLifestyle. All exercises are available on YouTube [35].

    In addition to the actual physical training, ActiveLifestyle features a set of individual and social motivation instruments. In general, individual motivation strategies aim to convince someone to do something because it is inherently enjoyable for this person, independently of any social pressure. ActiveLifestyle specifically supports:

    1. Conditioning through positive and negative reinforcement by immediately offering a reward/praise after an expected behavior to encourage the behavior and increase the probability that it happens again, or reprimands undesired behavior to decrease the probability of a reoccurrence of that behavior. Metaphors for reinforcement include a flower that grows whenever a session is completed (ie, positive reinforcement) and a gnome who takes care of the flower. The gnome’s mood status varies according to the person’s daily compliance to the plan (ie, positive and negative reinforcement; if the person performs the exercise, the gnome is happy, otherwise he is sad) (see panel a in Figure 2).
    2. Goal setting by establishing specific, measurable, achievable, and time-targeted goals. The goal is anticipated by visually conveying the achievable maximum growth of the flower (see panel b in Figure 2).
    3. Self-monitoring by allowing people to monitor themselves and to modify their attitudes and behaviors. Coloring the flower growth stages reflects progress toward the goal (see panel b in Figure 2).
    4. Awareness by presenting the benefits of being physically active through written content on a bulletin board and by showing inspiring stories (eg, link to newspapers, videos, or websites) (Figure 3).

    Social motivation strategies are built on social psychology. An individual’s social network (other trainees) may act as source of motivation. ActiveLifestyle uses:

    1. Comparison by allowing a person to compare similarities and differences between 2 or more parties. People tend to keep equality in their relationships. Whenever a person completes a workout session, an automatic message is posted on a bulletin board informing the training community (ie, other users following the same training plans) about the complete session. The message also carries the status of the individual’s flower.
    2. External monitoring by allowing 1 party to monitor the performance of another party. ActiveLifestyle enables health care experts to access data on performance and compliance with the training plan. The older users have access to their own flower and to that of their training partners, enabling monitoring progress of peers.
    3. Emotional support by encouraging exchange of written messages between trainees and experts to motivate and assist. ActiveLifestyle uses a bulletin board and an “inBox.” The first is a public channel where all members of the training community have access. The second is a bidirectional private channel for contact with professionals capable of giving advice and feedback on trainings.
    4. Collaboration by offering a collaborative activity designed as a game, in which to progress in the game, a group of trainees must jointly be compliant with the training plan. The To the Top game is a trekking trail with 24 predefined points (2/week). The aim of the game is to climb a mountaintop, as a group of successful trainings ends. Compliance with the training plan is evaluated twice weekly on group level. A total of 65% or more members of a group have to perform the scheduled workout to be awarded a new flag on the trail (representing progress toward the mountaintop). Each flag uncovers a story with trivia about the Matterhorn and what is needed to conquer the mountain as a parable explaining the benefits associated with being physically active (Figure 4).

    ActiveLifestyle comes in 2 versions. The individual version contains only the individual motivations strategies. The social version supports individual and social motivation strategies, and a virtual training plan community and communication features. In addition to the motivation strategies, ActiveLifestyle supports 6 main features accessible through its menu:

    1. The What’s Next? option invites the users to start the performance of due workout sessions.
    2. The weekly exercises option shows the scheduled strength–balance sessions organized per week.
    3. The progress option shows the users’ progress thought the conditioning, goal setting, and self-monitoring strategies previously mentioned in both versions. The social version also supports the collaboration strategy through the To the Top game.
    4. The bulletin board allows the users to receive written messages, which may include links for websites and YouTube videos. Three types of messages are supported: (1) workout session completed messages (in green) to inform the participant(s) about the conclusion of a scheduled session of exercises; (2) ActiveLifestyle tips messages (in pink) to support the awareness motivation strategy illustrated in Figure 3; and (3) public messages (in white) written by the training members. Only the social version supports the third type of message and has the ability to send messages to the entire training plan community.
    5. The friends option lists the members of the training plan community (ie, older users and experts). Only the social version supports this feature.
    6. The inBox option allows users to exchange private text messages with their list of friends.

    All the previously mentioned features and motivation strategies can be inspected at the Life Participation Project website [31].

    ‎
    Figure 1. Exercise examples.
    View this figure
    ‎
    Figure 2. Metaphors within the app to motivate older people through conditioning, goal setting, and self-monitoring.
    View this figure
    ‎
    Figure 3. ActiveLifestyle tips to improve awareness about the benefits of being physically active.
    View this figure
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    Figure 4. The To the Top collaboration game within the app.
    View this figure

    Eligibility Criteria

    Participants were older adults aged 65 years or older; living independently; able to walk independently with or without walking aids; able to follow instructions spoken in German, English, or Italian; and with no severe illness, cognitive impairment, progressive neurological disease, stroke, severe cardiac failure, or high blood pressure. Ethical approval for the study was obtained from the Eidgenössische Technische Hochschule (ETH) Ethics Committee (EK 2011-N-64).

    Setting

    Participants were recruited by convenience sampling from 2 institutions for older people and 1 organization responsible for coordinating and providing at-home nursing care for seniors. The Senioren Begegnungszentrum Baumgärtlihof, a day center dedicated to delivering services and information related to the older population (Horgen, Switzerland), advised potential participants through its mailing list and by notes in the local newspaper (Multimedia Appendix 1). The Alterswohnungen Turm-Matt, a cooperative offering housing and daily living facilities to older people (Wollerau, Switzerland), informed and advised potential participants in person or by phone and distributed flyers to advertise the study. The Fachstelle für präventive Beratung Spitex-Zürich, a home-care nursing organization (Spitex-Zürich), promoted the study by sending letters and specifically inviting patients in need of better physical performance. Spitex-Zürich nurses selected potential participants based on the eligibility criteria.

    Intervention

    To investigate the effects of different motivation strategies, a pretest/posttest preclinical trial was performed. For convenience, the ActiveLifestyle groups were composed of (1) an individual group that followed training using the individual version of ActiveLifestyle; (2) a social group that followed training using the social version of the app, (3) a control group that followed exercises with printed information without additional motivation strategy. The individual and social groups were randomly composed of participants recruited from Baumgärtlihof and Spitex-Zürich, whereas the participants in the control group were recruited from Turm-Matt because of time and resource constraints (eg, lack of research team members, the control group was not randomized with the other participants). Figure 5 shows the recruitment process and the flow of participants through the study. Videos of some parts of the interventions can be watched on YouTube [35].

    The development of our intervention follows a framework for the design and evaluation of complex interventions [36] and should at this stage be considered as a preclinical exploratory trial. For this reason, we did not use a pure randomized, controlled research design; therefore, we did not register this study as a clinical trial.

    Outcome Measures

    Adherence and Attrition

    Adherence was computed by ActiveLifestyle during the intervention and stored in a central database. The control group adherence was assessed with paper-based training logs. To calculate adherence, the total number of workout sessions for each participant was divided by 81, which was the total number of possible training sessions for the 12-week period (because of technical issues, the training was suspended for 3 days and the trainees were aware of the 81 training sessions in advance). The adherence of participants who dropped out was calculated by dividing the number of workout sessions attended up to the point of dropout from the study by 81 [37]. Values were compared between groups and with median rates in community-based fall prevention interventions [38]. For attrition, we measured the number of participants retained and lost at the final follow-up.

    Gait Speed

    The effect of the training on physical performance was assessed by measuring preferred and fast walking speed [39] with the GAITRite walkway, a valid and reliable tool for measuring gait in older people [40-42].

    Motivation Instruments

    The effectiveness of the motivation instruments built into the system was assessed based on the participants’ feedback, collected with a 7-point Likert scale self-reported questionnaire at the end of the intervention (Multimedia Appendixes 2 and 3), and on the performance (adherence, attrition, and gait speed) comparison among the 3 groups of participants.

    Change of Behavior

    The level of exercise adoption was evaluated according to the Transtheoretical Model (TTM) [43], which describes how people modify or acquire behavior. A self-reported TTM questionnaire (Multimedia Appendix 4) was applied before and after the training period. Participants were classified into 4 groups: contemplation (eg, thinking about physical behavior change), preparation (eg, already somewhat physically active), action (eg, doing enough physical activity), and maintenance (eg, making physical activity a habit).

    Statistical Analyses

    Analysis of variance (ANOVA) was used to test for differences in adherence to the training program between groups, as well as gait speed over time and between groups. Significant main effects were followed up by post hoc t tests with correction for multiple comparisons. Between-group differences in attrition were analyzed using a chi-square (χ2) test. Questionnaires on enjoyment, motivation, and change of behavior were analyzed using Kruskal–Wallis ANOVA and Wilcoxon signed rank tests (W). In all analyses, the level of significance was set at P≤.05. For effect size, we used η2 in all ANOVA analyses, Cohen’s d for all post hoc analyses, mean square contingency coefficient (φ) for chi-square tests, and Pearson r (r) for Kruskal–Wallis ANOVA and Wilcoxon signed rank tests. The r is calculated as r=Z/√N, in which Z is the standardized difference and N is the total number of samples. Suggested norms for interpreting η2 are 0.01=small, 0.06=moderate, and 0.14=large effect [44]. For small, moderate, and large effects, these norms are 0.2, 0.5, and 0.8, respectively, for Cohen’s d and 0.1, 0.3, and 0.5, respectively, for both φ and r [44]. All tests were conducted using SPSS Version 21.0 (IBM Corp, Armonk, NY, USA).

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    Figure 5. Flowchart of participants.
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    Demographics

    Detailed information about the participants’ demographics, based on the Health and Technology Familiarity self-reported questionnaires (Multimedia Appendixes 5 and 6), is summarized in Table 1.

    Adherence and Attrition

    Table 2 presents the adherence to ActiveLifestyle strength–balance training plans. Adherence across training plans differed significantly between groups (F2,41=4.8, P=.01 η2=0.19). Post hoc t tests with Benjamini–Hochberg correction revealed a large and significant difference between the social group (mean 81.9%, SD 1.6%) and the control group (mean 48.1%, SD 41.5%; t19.2=3.1, P=.02 d=0.91). The difference between the individual group (mean 71.1%, SD 25.2%) and the control group was moderate to large (t26.9=1.9, P=.10, d=0.63). The difference between the individual and social groups was moderate yet nonsignificant (t18.6=1.4, P=.19, d=0.50).

    Thirty-three older adults completed the 12 weeks of training, resulting in a 25% attrition rate in total, 21% in the individual group (3/14), 8% in the social group (1/13), and 41% in the control group (7/17). Figure 6 illustrates the number of remaining participants in each group per week after enrollment. More details about the dropout reasons are reported in Figure 5. A chi-square test revealed that attrition rate was higher in the control group (41.2%) than in the combined ActiveLifestyle groups (14.2%; χ21=3.9, P=.05, φ=0.30).

    Table 1. Participants’ demographics (N=44).
    CharacteristicIndividual (n=14)Social (n=13)Control (n=17)
    Female gender, n (%)10 (71)8 (62)10 (59)
    Age (years), mean (SD)74 (5)75 (6)76 (15)
    Hold trades or professional diploma, n (%)7 (50)7 (54)10 (59)
    In a sitting position past profession, n (%)7 (57)6 (46)6 (35)
    Health questions, n (%)



    		Estimated good health5 (36)8 (61)8 (47)

    		Estimated average balance7 (50)5 (38)9 (53)

    		Feel pain but not every day9 (64)7 (54)7 (41)
    Flexibility questions, n (%)



    		Fell in the past 6 monthsa2 (14)5 (38)4 (23)

    		Walk at least twice a week5 (36)8 (61)9 (53)

    		Practiced some sport in the past10 (71)8 (61)5 (29)

    		Never practiced strength exercises11 (79)7 (54)14 (82)
    Technology familiarity, n (%)



    		Frequently use automated teller machines7 (50)9 (69)7 (41)

    		Frequently use cellphones7 (50)10 (77)6 (35)

    		Frequently use digital photography8 (57)4 (31)4 (23)

    		Don’t use Global Positioning System devices7 (50)8 (61)6 (35)

    		Don’t use automatic kiosks9 (64)6 (46)12 (71)

    		Don’t know what an e-book is7 (50)5 (38)11 (65)

    		Use a computer12 (86)10 (77)8 (47)

    		Between 1-5 hours per week6 (43)4 (31)3 (18)

    		Use the Internet12 (86)9 (69)5 (29)

    		Between 1-5 hours per week7 (50)6 (46)2 (12)

    aA fall was defined as unintentionally coming to the ground or some lower level, excluding the consequence of sustaining a violent blow, loss of consciousness, or sudden onset of paralysis, such as during a stroke or epileptic seizure [45].

    Table 2. Adherence to ActiveLifestyle strength–balance training plans.
    Training planIndividual groupSocial groupControl group

    		VisitedPlanned%VisitedPlanned%VisitedPlanned%
    Balance training plan547812675497547345198646
    Strength training plan221322692172997329139174
    Across training plans768113468766105373742137754
    ‎
    Figure 6. Graph of the number of remaining participants in each group per week.
    View this figure

    Gait Speed

    Table 3 shows participants’ preferred and fast gait speed during the pretest and posttest evaluations. With respect to preferred gait speed, the 3 groups were similar. We used 2 mixed 2-way ANOVA’s (1 for preferred and 1 for fast gait) with within-subject factor pre–post (2 levels) and between-subject factor group (3 levels). For preferred gait speed, there was a significant difference between pretest and posttest (F1,29=29.5, P<.001, η2=0.50). Participants walked significantly faster in the posttest (1.276 m/s) than they did in the pretest (1.142 m/s). There was no significant main effect of group (P=.07) and no significant interaction effect (P=.65), suggesting that preferred gait speeds and their improvements were similar in all groups.

    The results for fast gait speed were similar to those for preferred gait speed. Again, there was a large difference between pretest and posttest: Participants walked significantly faster in the posttest (1.72 m/s) than in the pretest (1.56 m/s; F1,29=20.1, P<.001, η2=0.41). The main effect of group was significant also (F2,29=5.3, P=.01 η2=0.27). Post hoc tests revealed that the individual group (1.89 m/s) was significantly faster than the control group (1.45 m/s; t19=3.94, P=.003, d=1.31), and faster than the social group (1.58 m/s; t20=2.05, P=.08, d=.89), though not statistically significant. The individual group, by chance, was the fastest from the beginning. Fast gait speed was not significantly different between the control group and the social group (P=.39).

    Motivation Instruments

    Detailed information about the effectiveness of ActiveLifestyle’s motivation instruments and user-intention aspects are summarized in Table 4. The questionnaires used to collect the content of the table are available in Multimedia Appendixes 2 and 3.

    Most participants affirmed that ActiveLifestyle facilitates the autonomous performance of balance–strength exercises. This was confirmed by a high intention to use the app again or to recommend it to friends or family members. The individual group was unanimous in the evaluation of these 2 user-intention aspects, whereas the social group presented high values but not with unanimity. In general, the participants of both groups did not feel motivated to perform physical exercises before the study.

    All the participants thought it was fun to perform the strength and balance exercises. Few participants (<25%) felt frustrated, worried, or nervous during the study. More than half of the participants, 54% from the individual group and 67% from social group, will miss ActiveLifestyle.

    The individual motivation strategies seemed to be more effective on the individual group level than on the social group level. Most of the individual group felt motivated by the goal-setting and self-monitoring strategies (91%), both represented by the progress bar metaphor (panel b in Figure 2), as well as for being aware of the benefits of being physically active–aware (82%). Conditioning through positive and negative reinforcement also motivated the participants. In all, 64% felt motivated when they saw the plant growing, whereas 55% felt motivated by the mood status of the gnome.

    The most effective motivating strategies for the social group were conditioning through positive social inclusion and external monitoring (all 83%). After that, the social group felt motivated through the awareness of the benefits of physically activity (82%), emotional support (75%), the monitoring of their progress toward the plan (goal setting and self-monitoring) (67%), participation in the collaboration game (58%), positive and negative reinforcement (conditioning) (50%), and the comparison of their performance with other training participants on the bulletin board (42%).

    Most participants in the individual group (64%) expressed that they would feel more motivated if they could use the social version of ActiveLifestyle, but the reverse was not true. Only a few participants in the social group expected to be less motivated using the individual version of the app (8%).

    Mann–Whitney U tests comparing the Likert scores for all questions presented in Table 4 did not detect any significant differences between the groups.

    Change of Behavior

    Table 5 shows the stage of behavior change of the participants at the beginning (t0=0 weeks) and at the end (t1=12 weeks) of the intervention.

    Wilcoxon signed rank tests comparing pretest and posttest behavioral scores in each group revealed a trend—with a large effect size—in the social group (W=1.79, P=.07, r=0.52). Hence, the social group tended to change their behavior toward integration of ActiveLifestyle into their daily routine. No behavioral changes were detected in the control group (P=.28) or the individual group (P=.50). Although this suggests between group differences with respect to behavioral change, no such differences could be shown statistically; a Kruskal–Wallis ANOVA directly comparing change of behavior between the 3 groups was nonsignificant (P=.75).

    Table 3. Participants’ gait speed during the pretests and posttests.
    ConditionPretest mean (SD)Posttest mean (SD)
    Individual group


    		Preferred speed (m/s)1.26 (0.18)1.42 (0.21)

    		Fast speed (m/s)1.80 (0.27)1.98 (0.31)
    Social group


    		Preferred speed (m/s)1.10 (0.25)1.24 (0.31)

    		Fast speed (m/s)1.50 (0.35)1.66 (0.50)
    Control group


    		Preferred speed (m/s)1.07 (0.19)1.17 (0.22)

    		Fast speed (m/s)1.39 (0.22)1.51 (0.27)
    Table 4. Outcome data expressed by the participants on a 7-point Likert scale (range 1-7; 1=completely disagree to 7=completely agree) at the end of the intervention period.
    Evaluation statementsIndividual (n=14)Social (n=13)

    		Median (range)% AgreedMedian (range)% Agreed
    Statement




    		ActiveLifestyle facilitates the performance of autonomous strength–balance exercises at home7 (6-7)1007 (4-7)92
    Use intention




    		I would use the app again6 (5-7)1006 (4-7)83

    		I would recommend the app
    to my friends and family    		6 (6-7)1006 (3-7)67
    Enjoyment




    		It was fun to carry out the strength and balance exercises6 (6-7)1006 (5-7)100

    		I felt frustrated during the study2 (1-5)92 (1-6)8

    		I felt worried during the study2 (1-6)182 (1-7)25

    		I felt nervous during the study1 (1-6)91 (1-4)0

    		I will miss the exercises and the ActiveLifestyle app5 (2-7)546 (3-7)67
    Motivation




    		I usually do not feel motivated to perform physical exercises, ActiveLifestyle helped me6 (1-7)546 (2-7)83
    Individual motivation instruments




    		I felt motivated when I saw my performance on the progress bar (goal setting and self-monitoring)6 (4-7)916 (1-7)67

    		I felt motivated by being aware about the benefits of being physically active (awareness)6 (3-7)826 (3-7)82

    		I felt motivated when I saw the plant growing due to my performance (conditioning)6 (4-7)646 (1-7)83

    		I felt motivated when I saw the emotional status of the gnome (conditioning)5 (2-7)554 (1-6)50

    		I would feel more motivated using the social version of ActiveLifestyle, in which I could interact with other training partners5 (1-7)64——
    Social motivation instruments




    		I felt motivated for being part of a training group and knowing that other people did the same exercises——6 (2-7)83

    		I felt motivated to perform the plan because I knew I was being monitored (external monitoring)——6 (2-7)83

    		I felt motivated for being emotionally supported by the other training partners and by the ActiveLifestyle experts (emotional support)——6 (2-7)75

    		I felt motivated with the collaboration activity to reach the top of the mountain (collaboration)——6 (3-7)58

    		I usually compared my flower with others on the bulletin board (comparison)——4 (1-6)42

    		I would feel more motivated using the individual version of ActiveLifestyle, which does not require interaction with other training partners——4 (1-6)8
    Table 5. Stage of behavior change of the participants according to the Transtheoretical Model (TTM).
    Stage of behavior changet0 = 0 weekst1 = 12 weeks
    Individual group


    		Contemplation30

    		Preparation14

    		Action11

    		Maintenance66
    Social group


    		Contemplation53

    		Preparation20

    		Action00

    		Maintenance59
    Control group


    		Contemplation53

    		Preparation12

    		Action00

    		Maintenance45

    Principal Findings

    The aim of this study was to investigate (1) which IT-mediated motivation strategies increase adherence to physical exercise training plans in older people, (2) whether the ActiveLifestyle app induces physical activity behavior change, and (3) the effectiveness of the ActiveLifestyle training to improve gait speed. The main focus was to evaluate the ability to retain older people in the exercise program. Based on findings from a systematic review [39], we could expect a 10% attrition rate and 50% adherence rate for the individually targeted exercise training. Although the control group showed 41% attrition (primarily because of lack of exercise motivation), both tablet-based training groups showed far lower values, 21% and 8% for the individual and social ActiveLifestyle groups, respectively. These last 2 numbers also contain the effect of morbidities not related to the motivation to train (ie, unexpected health problems). Especially in the control group participants, the lack of motivation for continuous training was high. The degree of engagement with the intervention was more than 68% for the individual group and 73% for the social group, both using the ActiveLifestyle app, and 54% for the control group. Compared with median rates for attrition (10%) and adherence (50%) in fall prevention interventions in community settings, we achieved better or similar rates for the tablet-based training groups. From previous research [46], we know that the intention to undertake strength-balance training in older people is closely related to all elements of coping appraisal. Elements of coping appraisal include the belief that strength-balance training has multiple benefits, a positive social identity, and the feeling that family, friends, and doctors would approve of taking part in such training [46]. It can be hypothesized that ActiveLifestyle is effective in influencing attrition and adherence because it explicitly supports individual and social motivation instruments.

    The reason to use a tablet solution is related to the numerous potential advantages attributed to such a tool (eg, tablets are relatively robust, and using fingers instead of a mouse or a touch pad make them much more intuitive and easy to use compared with smartphones, notebooks, and desktops). A tablet-based intervention, such as ActiveLifestyle, constitutes a powerful tool to provide feedback about performance and motivation to endure practice because of social inclusion. Interventions that use frequent, nonfrequent, or direct remote feedback are to be favored versus treatments without feedback, because the former seem to be more effective than the latter and they are equally effective as supervised exercise interventions [47]. The second most-mentioned barrier to physical exercise for subjectively insufficiently active older adults is lack of company. Direct remote contact seems to be a good alternative to supervised on-site exercising [47]. Such feedback can easily be adapted to the individual participant’s baseline motor performance and progressively augmented with task difficulty. ActiveLifestyle has been demonstrated to have the potential to engage people who otherwise would lack interest to participate in a physical exercise regimen. Especially in the older population, it is difficult to maintain high adherence to training programs [48]. The participants of the present study allocated to the tablet groups showed good compliance rates. The losses related to low exercise compliance (n=6) in the control training group were caused by a lack of motivation. The reasons for discontinuation of training in the tablet groups were not because of rejection of the app; they were because of health problems. In a future phase III trial, the follow-up period for the assessment of adherence and attrition should preferably be extended to 12 months to enable the comparability of this future study with reference values of previous physical interventions [39]. Although the result of a 12-week intervention, our findings are encouraging and indicate the effectiveness of a tablet-based training approach in older people. This encourages further exploration of this training approach in seniors.

    Analyzing the participants’ answers to the motivation instruments of ActiveLifestyle, most of the individual participants (64%) would feel more motivated using the social version of the app, whereas the opposite is not true (8%) (both tablet groups were aware of the different versions of ActiveLifestyle). Regarding the physical activity habits, the training group using the social version of ActiveLifestyle was the only group showing a tendency to change behavior. At the end of the intervention, 50% of the social group participants changed their behavior according to the TTM. At the beginning, these participants were at the contemplation or preparation stages (thinking about or already being somewhat physically active), and they were classified as being on the maintenance stage (making physical activity a habit) by the end. However, a further longitudinal study with a larger sample, including evaluation after the end of the intervention, is required to be able to ascertain change of physical behavior.

    Gait speed is a clinically relevant indicator of functional status associated with important geriatric health outcomes (ie, impact health care activities have on people) [49]. Slowing down has been recognized as an indicator of failing health and vulnerable old age [50]. Some researchers hypothesize that gait speed may act as a vital sign, giving indications of the health status of older people. Mortality, for example, is substantially reduced when gait speed is improved through interventions [51]. Large epidemiological studies reveal that a 0.1 m/s faster walking speed is related to a 12% decrease in mortality [13]. In this respect, it is encouraging that all older people in our training groups that adhered to their training plan, independently of their group allocation, showed an increase in both preferred and fast walking speed.

    In addition to the high level of adherence caused by the social motivation instruments, the training community created by the study served to improve the connectedness of the participants, which may help people to garner social support for making physical changes in their daily lives [52]. Two women who did not know one another started to perform the exercises together to check if they were following the correct posture. Some participants contacted other training partners using the app or via email or phone when they faced problems. The same support was also requested from our team of experts, who frequently (especially at the beginning of the study) received phone calls because of technical problems or doubts about the exercises.

    As learned in our previous study [20], some of the participants felt proud of being able to use new technology. One of our oldest participants (83 years) installed Skype to call his daughter living in Central America. He confessed that his daughter was very surprised. In the beginning, 1 woman was afraid of not being able to correctly operate the tablet because she had never used a computer before. After the study, she bought a tablet on her own to play with her grandchildren and installed Wi-Fi at home to be more connected with them. Another woman expressed a similar concern at the beginning of the training, but finished the study with a new tablet and a Gmail account: “I’m proud to be in possession of the iPad and to be able to write to my friends. The whole matter was a change for me.”

    Limitations

    The study has some limitations. One of them is the rather small sample size. The study reveals first estimates for gait speed measures and stages of behavior change and warrants further research in larger populations. However, the purpose of preclinical exploratory trials is to provide preliminary evidence on the clinical efficacy of an intervention [16,36]. When evaluating the validity of a study, it is important to consider both the clinical and statistical significance of the findings [53]. Studies that claim clinical relevance may lack sufficient statistical significance to make meaningful statements or, conversely, may lack practicality despite showing a statistically significant difference in treatment options. Researchers and clinicians should not focus on small P values alone to decide whether a treatment is clinically useful; it is necessary to also consider the magnitude(s) of treatment differences and the power of the study [53]. Encouraging in this context is the observation that most of the between-groups comparisons for adherence show medium or medium-to-high magnitude(s) of treatment differences in favor of the tablet groups. The relationship between tablet-based physical training research and its effect on adherence and fitness in older individuals requires further exploration. Another limitation of this study is related to the research design used. The different recruitment methods and the lack of initial randomization and blinding may have introduced a selection bias that questions the validity of the adherence/motivation findings. Analogous studies with similar or frailer populations and the use of a true randomized controlled research design should be performed to substantiate or refute our findings.

    The participants of this study can be classified as normal walkers with a preferred gait speed between 1.0 and 1.4 m/s. Future studies with community dwelling populations that exhibit mildly abnormal (0.6-1.0 m/s) or seriously abnormal gait speed (<0.6 m/s) [50] should be performed to investigate whether similar or even better results in physical performance variables can be obtained.

    Conclusion

    The finding of this study supports the notion that it is advantageous to combine physical training with specifically targeted IT motivation instruments that offer the possibility to socialize in a group in clinical practice. The combination seems to have a positive influence on older adults’ training adherence in comparison to more traditional exercise. ActiveLifestyle proved to assist and motivate independently living and healthy older adults to autonomously perform strength–balance exercises. The social motivation strategies seemed to be more effective to stimulate the participants to comply with the training plan and remain on the intervention. The adoption of assistive technology devices for physical intervention tends to motivate and retain older people exercising for longer periods of time.

    Acknowledgments

    This work was carried out with the support of Maria Messmer-Capaul and her team at the Fachstelle für präventive Beratung Spitex-Zürich, of Claudia Nüesch at the Senioren Begegnungszentrum Baumgärtlihof, and Data Quest, who provided tablets for the study. We would like to thank all the participants for their great enthusiasm and support. This work is partially sponsored by the European Institute of Innovation & Technology (EIT) project Virtual Social Gym and the EU FP7 SME Capacities program BPM4People.

    Conflicts of Interest

    None declared.

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    Multimedia Appendix 1

    Das iPad sagt Knie beugen: Zürichsee-Zeitung.

    PDF File (Adobe PDF File), 209KB
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    Multimedia Appendix 2

    Individual feasibility questionnaire.

    PDF File (Adobe PDF File), 65KB
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    Multimedia Appendix 3

    Social feasibility questionnaire.

    PDF File (Adobe PDF File), 62KB
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    Multimedia Appendix 4

    Transtheoretical-model questionnaire.

    PDF File (Adobe PDF File), 49KB
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    Multimedia Appendix 5

    Technology familiarity questionnaire.

    PDF File (Adobe PDF File), 56KB
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    Multimedia Appendix 6

    Health questionnaire.

    PDF File (Adobe PDF File), 57KB
    1. Rowe JW, Kahn RL. Successful aging. The Gerontologist 1997;37(4):433-440. [CrossRef]
    2. Spirduso WW, Cronin DL. Exercise dose-response effects on quality of life and independent living in older adults. Med Sci Sports Exerc 2001 Jun;33(6 Suppl):598-608. [Medline]
    3. Johnson RJ, Wolinsky FD. The structure of health status among older adults: disease, disability, functional limitation, and perceived health. J Health Soc Behav 1993 Jun;34(2):105-121. [Medline]
    4. Malmberg JJ, Miilunpalo SI, Vuori IM, Pasanen ME, Oja P, Haapanen-Niemi NA. A health-related fitness and functional performance test battery for middle-aged and older adults: feasibility and health-related content validity. Arch Phys Med Rehabil 2002 May;83(5):666-677. [Medline]
    5. Malmberg J, Miilunpalo S, Pasanen M, Vuori I, Oja P. Characteristics of leisure time physical activity associated with risk of decline in perceived health--a 10-year follow-up of middle-aged and elderly men and women. Prev Med 2005 Jul;41(1):141-150. [Medline]
    6. American College of Sports Medicine, Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA, Minson CT, Nigg CR, et al. American College of Sports Medicine position stand. Exercise and physical activity for older adults. Med Sci Sports Exerc 2009 Jul;41(7):1510-1530. [Medline]
    7. Stuart M, Chard S, Benvenuti F, Steinwachs S. Community exercise: a vital component to healthy aging. Healthc Pap 2009;10(1):23-28. [Medline]
    8. US Department of Health and Human Services. 2002. Physical Activity Fundamental To Preventing Disease   URL: http://aspe.hhs.gov/health/reports/physicalactivity/ [accessed 2013-07-20] [WebCite Cache]
    9. Landi F, Abbatecola AM, Provinciali M, Corsonello A, Bustacchini S, Manigrasso L, et al. Moving against frailty: does physical activity matter? Biogerontology 2010 Oct;11(5):537-545. [CrossRef] [Medline]
    10. Thibaud M, Bloch F, Tournoux-Facon C, Brèque C, Rigaud AS, Dugué B, et al. Impact of physical activity and sedentary behaviour on fall risks in older people: a systematic review and meta-analysis of observational studies. Eur Rev Aging Phys Act 2011;8(1):5-15.
    11. Hilbe J, Schulc E, Linder B, Them C. Development and alarm threshold evaluation of a side rail integrated sensor technology for the prevention of falls. Int J Med Inform 2010 Mar;79(3):173-180. [CrossRef] [Medline]
    12. Mei YY, Marquard J, Jacelon C, Defeo AL. Designing and evaluating an electronic patient falls reporting system: Perspectives for the implementation of health information technology in long-term residential care facilities. Int J Med Inform 2011 Apr 7:[Epub ahead of print]. [CrossRef] [Medline]
    13. Studenski S, Perera S, Patel K, Rosano C, Faulkner K, Inzitari M, et al. Gait speed and survival in older adults. JAMA 2011 Jan 5;305(1):50-58 [FREE Full text] [CrossRef] [Medline]
    14. Ferrucci L, Baldasseroni S, Bandinelli S, de Alfieri W, Cartei A, Calvani D, et al. Disease severity and health-related quality of life across different chronic conditions. J Am Geriatr Soc 2000 Nov;48(11):1490-1495. [Medline]
    15. Obi T, Ishmatova D, Iwasaki N. Promoting ICT innovations for the ageing population in Japan. Int J Med Inform 2013 Apr;82(4):e47-e62. [CrossRef] [Medline]
    16. Thabane L, Ma J, Chu R, Cheng J, Ismaila A, Rios LP, et al. A tutorial on pilot studies: the what, why and how. BMC Med Res Methodol 2010;1:1-10 [FREE Full text] [CrossRef] [Medline]
    17. University of Trento. Apple App Store. 2012. IT4Life ActiveLifestyle   URL: https://itunes.apple.com/us/app/it4life-activelifestyle/id465295073?mt=8 [accessed 2013-07-18] [WebCite Cache]
    18. Stuck AE, Egger M, Hammer A, Minder CE, Beck JC. Home visits to prevent nursing home admission and functional decline in elderly people: systematic review and meta-regression analysis. JAMA 2002 Feb 27;287(8):1022-1028. [Medline]
    19. Eckert JK, Morgan LA, Swamy N. Preferences for receipt of care among community-dwelling adults. J Aging Soc Policy 2004;16(2):49-65. [CrossRef] [Medline]
    20. Silveira P, van het Reve E, Daniel F, Casati F, de Bruin ED. Motivating and assisting physical exercise in independently living older adults: a pilot study. Int J Med Inform 2013 May;82(5):325-334. [Medline]
    21. Mann WC, Ottenbacher KJ, Fraas L, Tomita M, Granger CV. Effectiveness of assistive technology and environmental interventions in maintaining independence and reducing home care costs for the frail elderly. A randomized controlled trial. Arch Fam Med 1999;8(3):210-217. [Medline]
    22. Huckvale K, Car M, Morrison C, Car J. Apps for asthma self-management: a systematic assessment of content and tools. BMC Med 2012;10:144 [FREE Full text] [CrossRef] [Medline]
    23. Gay V, Leijdekkers P. Personalised mobile health and fitness apps: lessons learned from myFitnessCompanion®. Stud Health Technol Inform 2012;177:248-253. [Medline]
    24. Donkin L, Christensen H, Naismith SL, Neal B, Hickie IB, Glozier N. A systematic review of the impact of adherence on the effectiveness of e-therapies. J Med Internet Res 2011;13(3):e52 [FREE Full text] [CrossRef] [Medline]
    25. Zwerver J, Weir A, Tol JL. What’s app? sports medicine physicians should not talk double Dutch. Br J Sports Med 2012 Sep;46(12):833-834. [Medline]
    26. Kelders SM, Kok RN, Ossebaard HC, Van Gemert-Pijnen JE. Persuasive system design does matter: a systematic review of adherence to web-based interventions. J Med Internet Res 2012;14(6):e152 [FREE Full text] [CrossRef] [Medline]
    27. Consolvo S, Klasnja P, McDonald DW, Landay JA. Goal-setting considerations for persuasive technologies that encourage physical activity. 2009 Presented at: 4th international Conference on Persuasive Technology; Apr 26-29, 2009; Claremont, CA. [CrossRef]
    28. Lin JJ, Mamykina L, Lindtner S. Fish’n’steps: Encouraging physical activity with an interactive computer game. Ubiquitous Computing 2006:261-278.
    29. Albaina IM, Visser T, van der Mast C. Flowie: A persuasive virtual coach to motivate elderly individuals to walk. 2009 Presented at: 3rd International Conference on Pervasive Computing Technologies for Healthcare; Apr 1-3, 2009; London p. 1-7.
    30. Silveira P, Daniel F, Casati F, van het Reve E, de Bruin ED. International Reports on Socio-Informatics: Designing for Inter/Generational Communities. 2012. ActiveLifestyle: an application to help elderly stay physically and socially active   URL: http://www.iisi.de/fileadmin/IISI/upload/IRSI/IRSI-Vol9-Iss1-2012-finale.pdf [accessed 2013-07-20] [WebCite Cache]
    31. LifeParticipation Project. 2012.   URL: http://www.lifeparticipation.org/active.html [accessed 2013-07-18] [WebCite Cache]
    32. YouTube. 2012. ActiveLifestyle app video   URL: http://www.youtube.com/watch?v=XSFjHcUtt_A&feature=youtu.be [accessed 2013-07-18] [WebCite Cache]
    33. Cress ME, Buchner DM, Prohaska T, Rimmer J, Brown M, Macera C, et al. Best practices for physical activity programs and behavior counseling in older adult populations. J Aging Phys Act 2005 Jan;13(1):61-74. [Medline]
    34. Kraemer WJ, Ratamess NA. Fundamentals of resistance training: progression and exercise prescription. Med Sci Sports Exerc 2004 Apr;36(4):674-688. [Medline]
    35. YouTube. 2012. LifeParticipation Project: ActiveLifestyle videos   URL: http://www.youtube.com/user/psilvieraf81?feature=results_main [accessed 2013-07-18] [WebCite Cache]
    36. YouTube. 2012. Longer study of the Active Lifestyle app in Switzerland   URL: http://www.youtube.com/watch?v=mNaIOYqN6tU&feature=youtu.be [accessed 2013-07-18] [WebCite Cache]
    37. Campbell M, Fitzpatrick R, Haines A, Kinmonth AL, Sandercock P, Spiegelhalter D, et al. Framework for design and evaluation of complex interventions to improve health. BMJ 2000 Sep 16;321(7262):694-696 [FREE Full text] [Medline]
    38. Arikawa AY, O'Dougherty M, Schmitz KH. Adherence to a strength training intervention in adult women. J Phys Act Health 2011 Jan;8(1):111-118 [FREE Full text] [Medline]
    39. Nyman SR, Victor CR. Older people's participation in and engagement with falls prevention interventions in community settings: an augment to the Cochrane systematic review. Age Ageing 2012 Jan;41(1):16-23 [FREE Full text] [CrossRef] [Medline]
    40. de Bruin ED, Schmidt A. Walking behaviour of healthy elderly: attention should be paid. Behav Brain Funct 2010;6:59 [FREE Full text] [CrossRef] [Medline]
    41. McDonough AL, Batavia M, Chen FC, Kwon S, Ziai J. The validity and reliability of the GAITRite system's measurements: A preliminary evaluation. Arch Phys Med Rehabil 2001 Mar;82(3):419-425. [CrossRef] [Medline]
    42. Hartmann A, Luzi S, Murer K, de Bie RA, de Bruin ED. Concurrent validity of a trunk tri-axial accelerometer system for gait analysis in older adults. Gait Posture 2009 Apr;29(3):444-448. [CrossRef] [Medline]
    43. Prochaska JO, Butterworth S, Redding CA, Burden V, Perrin N, Leo M, et al. Initial efficacy of MI, TTM tailoring and HRI's with multiple behaviors for employee health promotion. Prev Med 2008 Mar;46(3):226-231 [FREE Full text] [CrossRef] [Medline]
    44. Cohen J. Statistical Power Analysis for the Behavioural Sciences. Hillsdale, NJ: L Erlbaum Associates; 1988.
    45. Gibson MJ, Andres RO, Isaacs B. The prevention of falls in later life. A report of the Kellogg International Work Group on the Prevention of Falls by the Elderly. Dan Med Bull 1987 Apr;34 Suppl 4:1-24. [Medline]
    46. Yardley L, Donovan-Hall M, Francis K, Todd C. Attitudes and beliefs that predict older people's intention to undertake strength and balance training. J Gerontol B Psychol Sci Soc Sci 2007 Mar;62(2):P119-P125. [Medline]
    47. Geraedts H, Zijlstra A, Bulstra SK, Stevens M, Zijlstra W. Effects of remote feedback in home-based physical activity interventions for older adults: a systematic review. Patient Educ Couns 2013 Apr;91(1):14-24. [CrossRef] [Medline]
    48. Moschny A, Platen P, Klaassen-Mielke R, Trampisch U, Hinrichs T. Barriers to physical activity in older adults in Germany: a cross-sectional study. Int J Behav Nutr Phys Act 2011;8:121 [FREE Full text] [CrossRef] [Medline]
    49. Ostir GV, Berges I, Kuo YF, Goodwin JS, Ottenbacher KJ, Guralnik JM. Assessing gait speed in acutely ill older patients admitted to an acute care for elders hospital unit. Arch Intern Med 2012 Feb 27;172(4):353-358 [FREE Full text] [CrossRef] [Medline]
    50. Studenski S. Bradypedia: is gait speed ready for clinical use? J Nutr Health Aging 2009 Dec;13(10):878-880. [Medline]
    51. Hardy SE, Perera S, Roumani YF, Chandler JM, Studenski SA. Improvement in usual gait speed predicts better survival in older adults. J Am Geriatr Soc 2007 Nov;55(11):1727-1734. [CrossRef] [Medline]
    52. Anderson-Bill ES, Winett RA, Wojcik JR. Social cognitive determinants of nutrition and physical activity among web-health users enrolling in an online intervention: the influence of social support, self-efficacy, outcome expectations, and self-regulation. J Med Internet Res 2011;13(1):e28 [FREE Full text] [CrossRef] [Medline]
    53. Bhardwaj SS, Camacho F, Derrow A, Fleischer AB, Feldman SR. Statistical significance and clinical relevance: the importance of power in clinical trials in dermatology. Arch Dermatol 2004 Dec;140(12):1520-1523. [CrossRef] [Medline]

    ‎
    ANOVA: analysis of variance
    ETH: Eidgenössische Technische Hochschule
    IT: information technology
    TTM: Transtheoretical Model

    Edited by G Eysenbach; submitted 14.02.13; peer-reviewed by MC Costabile, E Stanmore; comments to author 21.03.13; revised version received 25.04.13; accepted 08.06.13; published 12.08.13

    Copyright

    ©Patrícia Silveira, Rolf van de Langenberg, Eva van het Reve, Florian Daniel, Fabio Casati, Eling D de Bruin. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 12.08.2013.

    This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.