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Cited by 85Mobile Health and mHealth ApplicationsPhysical Activity and HealthDigital Mental Health Interventions

Which Components of a Smartphone Walking App Help Users to Reach Personalized Step Goals? Results From an Optimization Trial

Open access
Kramer, Jan-Niklas, Künzler, Florian, Mishra, Varun, Smith, Shawna N, Kotz, David, Scholz, Urte, Fleisch, Elgar, Kowatsch, Tobias·2020·Annals of Behavioral Medicine
DOI 10.1093/abm/kaaa002PMC PMC7291330
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Abstract

Background: The Assistant to Lift your Level of activitY (Ally) app is a smartphone application that combines financial incentives with chatbot-guided interventions to encourage users to reach personalized daily step goals. Purpose: To evaluate the effects of incentives, weekly planning, and daily self-monitoring prompts that were used as intervention components as part of the Ally app. Methods: We conducted an 8 week optimization trial with n = 274 insurees of a health insurance company in Switzerland. At baseline, participants were randomized to different incentive conditions (cash incentives vs. charity incentives vs. no incentives). Over the course of the study, participants were randomized weekly to different planning conditions (action planning vs. coping planning vs. no planning) and daily to receiving or not receiving a self-monitoring prompt. Primary outcome was the achievement of personalized daily step goals. Results: Study participants were more active and healthier than the general Swiss population. Daily cash incentives increased step-goal achievement by 8.1%, 95% confidence interval (CI): [2.1, 14.1] and, only in the no-incentive control group, action planning increased step-goal achievement by 5.8%, 95% CI: [1.2, 10.4]. Charity incentives, self-monitoring prompts, and coping planning did not affect physical activity. Engagement with planning interventions and self-monitoring prompts was low and 30% of participants stopped using the app over the course of the study. Conclusions: Daily cash incentives increased physical activity in the short term. Planning interventions and self-monitoring prompts require revision before they can be included in future versions of the app. Selection effects and engagement can be important challenges for physical-activity apps. Clinical Trial Information: This study was registered on ClinicalTrials.gov, NCT03384550.

AI snapshot

Written from the paper’s full text.

TL;DR

In an 8-week optimization trial with 274 Swiss insurees, daily cash incentives increased achievement of personalized step goals by 8.1%, while charity incentives, self-monitoring prompts, and coping planning did not affect physical activity. Action planning helped only in the no-incentive control group, and low engagement plus 30% app discontinuation limited the notification-dependent components.

Key findings

  • Cash incentives increased daily step-goal achievement by 8.1% (95% CI: 2.1–14.1) versus control; charity incentives showed 6.9% (95% CI: 1.0–12.8) but this was no longer statistically significant after adjusting for missing data. Step-count differences were not statistically significant: cash +783 steps (95% CI: −135–1,701), charity +602 steps (95% CI: −305–1,509).
  • Action planning had no significant main effect overall, but in the no-incentive control group it increased step-goal achievement by 5.8% (95% CI: 1.2–10.4) in the adjusted model; the interaction with cash incentives was −7.1% (95% CI: −14.0 to −0.1). Coping planning did not affect physical activity.
  • Self-monitoring prompts had no significant effect on daily goal achievement (1.1%, 95% CI: −1.1–3.2) or steps/day (43, 95% CI: −114–200). In exploratory analyses, engaging with self-monitoring prompts was associated with +5.5% goal achievement (95% CI: 2.7–8.2) and +405 steps (95% CI: 189–621), while not engaging was associated with −9.3% (95% CI: −13.0 to −5.6) and −754 steps (95% CI: −1,077 to −431).
  • Engagement was low: response rates ranged from 40.6% for coping-planning exercises to 55.4% for self-monitoring prompts, and 83 of 274 participants (30.3%) stopped using the app by study end. Participants averaged 6,336 steps/day at baseline and increased by 438 steps (95% CI: 134–742) during the intervention.

Methods

  • An 8-week optimization trial (2-week run-in/baseline plus 6-week intervention) with n = 274 German-speaking insurees of a Swiss health insurance company; the Ally app set personalized daily step goals at the 60th percentile of the past 9 days’ step-count distribution, capped at 10,000 steps/day.
  • Randomization: at baseline to cash incentives, charity incentives, or no incentives (probability .33 each); weekly to action planning, coping planning, or no planning; daily to receiving or not receiving a self-monitoring prompt (probability .50). Primary outcome was the proportion of participant days that daily step goals were achieved; secondary outcomes included steps/day and self-reported motivation.
  • Analysis used linear regression for baseline-randomized incentives and generalized estimating equations following Boruvka et al. for microrandomized planning and self-monitoring components; primary analyses were complete-case, with sensitivity intention-to-treat and adjusted models including age, gender, baseline step count, smartphone operating system, employment, time trends, and weekend indicators, plus multiple imputation for missing data.

Limitations

  • The paper states the sample was healthier and more active than the general Swiss population, which may limit generalizability; it could not separate increases in step counts from increases in the time participants carried their smartphones; and it could not exclude use of other apps or devices that might affect Ally use or intervention effectiveness.
  • The paper states that engagement with planning and self-monitoring was low, planning interventions may have been burdensome (about 35% found planning exercises difficult; 50% preferred daily rather than weekly planning), and random delivery timing may have contributed to limited engagement.
  • The text makes evident that the exploratory engagement findings may reflect unobserved confounding—for example, smartphone carrying time could affect both recorded step counts and responding to intervention conversations—so those analyses remain inconclusive.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1093/abm/kaaa002

Cites

46 of 46 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 23 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Charity incentives did not affect physical activity.

    “Charity incentives, self-monitoring prompts, and coping planning did not affect physical activity.”
    Quote in the paperSubstantial claim
  • Findingown data

    Daily cash incentives increased step-goal achievement by 8.1 percentage points (95% CI 2.1 to 14.1) among participants.

    “Daily cash incentives increased step-goal achievement by 8.1%, 95% confidence interval (CI): [2.1, 14.1]”
    Quote in the paperSubstantial claim
  • Findingown data

    Self-monitoring prompts did not affect physical activity.

    “Charity incentives, self-monitoring prompts, and coping planning did not affect physical activity.”
    Quote in the paperSubstantial claim
  • Findingown data

    Coping planning did not affect physical activity.

    “Charity incentives, self-monitoring prompts, and coping planning did not affect physical activity.”
    Quote in the paperSubstantial claim
  • Findingown data

    30% of participants stopped using the Ally app over the course of the study.

    “30% of participants stopped using the app over the course of the study.”
    • Also stated in: § Sample · plain
      “At the end of the study, 83 of 274 participants (30.3%) had stopped using the Ally app.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim. 24
  • May combine two claims. 25

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Study participants were more active and healthier than the general Swiss population.

    “Study participants were more active and healthier than the general Swiss population.”
    • Also stated in: § Sample · hedged
      “Comparisons of participants’ baseline step counts (Table 1) with large-scale step count data from physical activity app users in Switzerland (37), and of SF-12 component summary scores with the German 12-item Short Form norm sample (38), indicate that (on average) participants in our study were healthier and more active than the general population.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [37] Althoff, 2017, Large-scale physical activity data reveal worldwide activity inequality, Nature. source

      Not checked in the free run.

    • cites [38] Morfeld, 2011

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Adding the interaction between planning exercises and incentive types revealed larger effects from both planning exercises in the no-incentive control group and decreased effects in the cash- and charity-incentive groups, although neither main effects nor interactions were statistically significant.

    “Adding the interaction between planning exercises and incentive types revealed larger effects from both planning exercises in the no-incentive control group and decreased effects in the cash- and charity-incentive groups, although neither main effects nor interactions were statistically significant.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In the complete case analysis, there was a statistically significant linear change in the effect of self-monitoring prompts on step-goal achievement over time, leading to a statistically significant positive effect around 4 weeks into the study.

    “In the complete case analysis, we found a statistically significant linear change in the effect of self-monitoring prompts on step-goal achievement over time, leading to a statistically significant positive effect of self-monitoring prompts around 4 weeks into the study.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    When adding the interaction between incentive conditions and self-monitoring prompts, the main effect of self-monitoring prompts in the incentive control group and the interaction terms were statistically not significant.

    “When adding the interaction effect between incentive conditions and self-monitoring prompts to the model, the main effect of self-monitoring prompts in the incentive control group and the interaction terms were statistically not significant.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Engaging with coping-planning conversations was associated with a higher proportion of step-goal achievement, but this was not statistically significant, 3.5%, 95% CI -0.03 to 7.0.

    “but not for coping planning (3.5%, 95% CI: [−0.03, 7.0])”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Out of three possible plans, participants articulated on average 0.6 action plans and 0.4 coping plans per week.

    “Out of three possible plans, participants articulated 0.6 action plans and 0.4 coping plans per week on average.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Not engaging with coping-planning conversations was associated with a lower proportion of step goals met, but this difference was not statistically significant, -3.4%, 95% CI -7.3 to 0.5.

    “coping planning: −3.4%, 95% CI: [−7.3, 0.5]).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Not engaging with action-planning conversations was associated with a lower proportion of step goals met, but this difference was not statistically significant, -2.0%, 95% CI -6.5 to 2.5.

    “Not engaging with planning conversations was associated with a lower proportion of step goals met, but this difference was not statistically significant (action planning: −2.0%, 95% CI: [−6.5, 2.5];”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    A graphical illustration suggests a curvilinear increase of step counts that starts during the baseline period and stabilizes around 2 weeks into the intervention period.

    “However, a graphical illustration of participants’ step counts over time suggests a curvilinear increase of step counts that starts already during the baseline period and stabilizes around 2 weeks into the intervention period (Supplementary Material, Section IV).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Action-planning intervention did not significantly affect weekly proportions of step goals achieved or weekly average steps per day when averaged over incentive conditions.

    “Neither action-planning nor coping-planning interventions significantly affected weekly proportions of step goals achieved or weekly average steps per day when averaged over incentive conditions (Table 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Not engaging with action-planning conversations was associated with lower step counts, but this was not statistically significant, -250 steps, 95% CI -701 to 201.

    “but not for action planning (−250 steps, 95% CI: [−701, 201]).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Models of steps per day revealed no meaningful or statistically significant main effects and interactions for planning interventions.

    “Models of steps per day revealed no meaningful or statistically significant main effects and interactions (Supplementary Material, Section II).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    A considerable proportion of participants stopped using the app over the 8-week study, although attrition appeared somewhat lower compared to similar studies of mHealth apps.

    “In addition, a considerable proportion of participants stopped using the app over the course of the 8 week study, although attrition appeared to be somewhat lower compared to similar studies of mHealth apps (42, 44).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [42] Shcherbina, 2019;1:344–352, The effect of digital physical activity interventions on daily step count: A randomised controlled crossover substudy of the MyHeart Counts Cardiovascular Health Study, Lancet Digit Health source

      Not checked in the free run.

    • cites [44] Dorsey, 2017, The use of smartphones for health research, Acad Med. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    If external rewards reduce intrinsic motivation in health behavior, such effects would be detrimental because intrinsic motivation is associated with maintained health-behavior change.

    “If applied to health behavior, such effects would be detrimental because intrinsic motivation has been associated with maintained health-behavior change (20).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Teixeira, 2012, Exercise, physical activity, and self-determination theory: A systematic review, Int J Behav Nutr Phys Act. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The study conducted sensitivity analyses for missing data (intention-to-treat) and for adjustment of covariates of physical activity (adjusted intention-to-treat).

    “We conducted sensitivity analyses for missing data (intention-to-treat analysis) and for adjustment of covariates of physical activity (adjusted intention-to-treat analysis).”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Missing data are missing at random (MAR).

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The summary effect of stand-alone physical activity apps was estimated at 477 steps per day (95% CI −230 to 1,183).

    “For example, the summary effect of stand-alone physical activity apps was estimated at 477 steps per day, 95% confidence interval (CI): [−230, 1,183] (7).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Romeo, 2019, Can smartphone apps increase physical activity? systematic review and meta-analysis, J Med Internet Res. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Smartphones are capable of accurately measuring physical activity in controlled and uncontrolled settings.

    “Smartphones are capable of accurately measuring physical activity in controlled and uncontrolled settings (30)”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [30] Hekler, 2015, Validation of physical activity tracking via android smartphones compared to actigraph accelerometer: Laboratory-based and free-living validation studies, JMIR Mhealth Uhealth. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Self-determination theory predicts that external rewards reduce intrinsic motivation if they are perceived as controlling the target behavior.

    “However, self-determination theory (18) predicts that external rewards reduce intrinsic motivation, if they are perceived as controlling the target behavior.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [18] Deci, 1985 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Smartphones may underestimate absolute step counts in free-living conditions because they are not always continuously carried.

    “but smartphones may underestimate absolute step counts in free-living conditions because they are not always continuously carried (31).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Duncan, 2018, Walk this way: Validity evidence of iphone health application step count in laboratory and free-living conditions, J Sports Sci. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    Due to technical errors, six participants did not always receive the interventions they were assigned, and they were analyzed according to their randomized intervention schedules.

    “Due to technical errors, six participants did not always receive the interventions they were assigned. Like all participants, we analyzed these six participants according to their randomized intervention schedules.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Adjusted models included age, gender, baseline step count, smartphone operating system, and employment as covariates.

    “Covariates included in all adjusted models were age, gender, baseline step count, smartphone operating system, and employment.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Large attrition rates observed for many mHealth apps suggest that intentions may diminish over time and volitional intervention strategies need to be supported by motivational strategies.

    “However, the large attrition rates observed for many mHealth apps (15) suggest that intentions may diminish over time and volitional intervention strategies need to be supported by intervention strategies that target motivation.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [15] Baumel, 2019, Objective user engagement with mental health apps: Systematic search and panel-based usage analysis, J Med Internet Res. source

      Not checked in the free run.

    • Rests on an assumption: The intention to change is a prerequisite for the effectiveness of volitional intervention strategies.

  • May combine two claims.

    Interpretationown data

    Selection effects and engagement can be important challenges for physical-activity apps.

    “Selection effects and engagement can be important challenges for physical-activity apps.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Klasnja et al. proposed the microrandomized trial (MRT) as an optimization trial design for mobile-health interventions.

    “Klasnja et al. proposed the microrandomized trial (MRT) (9), an optimization trial design for mobile-health interventions.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [9] Klasnja, 2015, Microrandomized trials: An experimental design for developing just-in-time adaptive interventions, Health Psychol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Longitudinal models were adjusted for linear time trends and a binary indicator for weekend days.

    “In addition, we adjusted longitudinal models for linear time trends and a binary indicator for weekend days.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    All analyses were prespecified.

    “All analyses were prespecified (21).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] Kramer, 2019, Investigating intervention components and exploring states of receptivity for a smartphone app to promote physical activity: Protocol of a microrandomized trial, JMIR Res Protoc. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Participants responded only to roughly half of the self-monitoring prompt and planning conversations initiated by the Ally chatbot, ultimately limiting the potential of both interventions to affect behavior.

    “Most importantly, participants responded only to roughly half of the self-monitoring prompt and planning conversations that were initiated by the Ally chatbot, ultimately limiting the potential of both interventions to affect behavior.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The ethical review board of ETH Zurich approved all study procedures.

    “The ethical review board of ETH Zurich approved all study procedures.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    At the beginning of the study, participants were randomized to one of nine sequences of the intervention schedule that determined the order of planning and control conditions.

    “At the beginning of the study, we randomized participants to one of the nine different sequences of the intervention schedule that determined the order of planning and control conditions during the study.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Action planning appeared to be an effective intervention for participants who did not receive financial incentives but had no effect for participants in either incentive group.

    “However, action planning appeared to be an effective intervention for participants who did not receive financial incentives but had no effect for participants in either of the incentive groups.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    Participants were randomized daily to receive or not receive a self-monitoring prompt with probability 0.50.

    “For each day from Monday through Saturday, we randomly assigned participants to either receive or not receive a self-monitoring prompt (probability 0.50).”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Planning interventions were delivered according to a uniform and strongly balanced intervention schedule that controlled for time and carryover effects during the 6-week intervention period.

    “Ally sent planning interventions according to a uniform and strongly balanced intervention schedule that controlled for time and carryover effects during the 6 week intervention period.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Informed consent was obtained from all individual participants included in the study.

    “We obtained informed consent from all individual participants included in the study.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Baseline characteristics indicate that the study attracted individuals who were more active, educated, and healthy than the general Swiss population.

    “Indeed, baseline characteristics indicate that our study attracted individuals who were more active, educated, and healthy than the general Swiss population.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    In addition to cash incentives, action planning can be a powerful intervention, although effects of both components may not fully unfold if offered simultaneously.

    “Thus, in addition to cash incentives, action planning can be a powerful intervention, although effects of both components may not fully unfold if offered simultaneously.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Daily cash incentives, but not charity incentives, promoted the achievement of personalized step goals during the 6-week intervention period.

    “Daily cash incentives—but not charity incentives—promoted the achievement of personalized step goals during the 6 week intervention period.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The study was registered on ClinicalTrials.gov (NCT03384550).

    “The study is registered on ClinicalTrials.gov (NCT03384550).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The anonymized data set and analysis script for the primary analyses are available online.

    “The anonymized data set and the analysis script for the primary analyses from this study are available online: https://osf.io/uc765/?view_only=334e8e3df14d4677b9296959d06c2c00.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    Blocked randomization with a block size of 9 and a randomization probability of 0.11 was used to guarantee balance between sequences.

    “To guarantee balance between the sequences, we used blocked randomization with a block size of 9 and a randomization probability of 0.11.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Use of additional apps or devices could potentially affect the use of the Ally app and the effectiveness of interventions.

    “Use of such additional apps or devices could potentially affect the use of the Ally app and the effectiveness of interventions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Notification-dependent interventions, that is, planning exercises and self-monitoring prompts, are limited by low engagement of participants with the interventions and high intervention burden and therefore require revision.

    “Notification-dependent interventions, that is, planning exercises and self-monitoring prompts, are limited by low engagement of participants with the interventions and high intervention burden and, therefore, require revision.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Selection effects and lack of sustained participant engagement can limit the health impact of physical activity apps considerably.

    “Unfortunately, selection effects and lack of sustained participant engagement can limit the health impact of physical activity apps (and other health apps) considerably.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    It is possible that the reported intervention effects reflect, at least partly, increases in the time the smartphone was carried.

    “It is possible that the reported intervention effects reflect, at least partly, increases in the time the smartphone was carried.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    Although all participants indicated upon enrollment that they were not using comparable apps or devices, the study cannot exclude that such apps or devices were used or that participants primarily used Apple Health or GoogleFit.

    “Lastly, although all participants indicated upon enrollment that they were not using any comparable apps or devices for tracking physical activity, we cannot exclude that such apps or devices were used or that participants primarily used the Apple Health or GoogleFit applications that were required for the Ally app to obtain step counts.”
    Quote in the paperNot a substantial claim
44 of 44

  • The authors state this as an assumption.

    Missing data are missing at random (MAR).

    “we assumed missing data to be “missing at random” (MAR) and used multiple imputation to create 10 complete data sets.”

  • The paper relies on this without support.

    The intention to change is a prerequisite for the effectiveness of volitional intervention strategies.

    “Naturally, the intention to change is a prerequisite for the effectiveness of volitional intervention strategies.”

  • The paper relies on this without support.

    Smartphone-recorded step counts accurately reflect participants' walking.

    “we were not able to separate increases in step counts from increases in the time that participants were carrying their smartphone.”
3 of 3

Claims other papers make about this one

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Cites

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Research works printed but not linked: 1

  1. World Health Organization, 2010, Global Recommendations on Physical Activity for Health

Cited by

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Related

Authors
Kramer, J.-N., Künzler, F., Mishra, V., Smith, S. N., Kotz, D., Scholz, U., Fleisch, E., & Kowatsch, T.
Affiliations
  • University of St.Gallen (CH)
  • ETH Zurich (CH)
  • Dartmouth College (US)
  • University of Michigan (US)
  • University of Zurich (CH)
Corresponding author
Kramer, Jan-Niklas
ORCID
Venue
Annals of Behavioral Medicine
Publisher
Oxford University Press (OUP)
Published
2020-03-17
Volume
54
Issue
7
Pages
518-528
ISSN
  • 0742-5554 (ISSN-L)
  • 0883-6612
  • 1532-4796
DOI
10.1093/abm/kaaa002
PMC
PMC7291330
OpenAlex
W3012299117
Semantic Scholar
1c788d3ca0272bf185de8b7447985878eb9d8c4c
Cited by
84
References
46
Citations by year
2026: 10 · 2025: 11 · 2024: 15 · 2023: 14 · 2022: 18 · 2021: 13 · 2020: 3
FWCI
12.53
Type
journal article
Language
en
Open access
Licence
Locations
  • Annals of Behavioral Medicine (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • Alexandria (UniSG) (University of St.Gallen) (acceptedVersion)
  • Zurich Open Repository and Archive (University of Zurich) (acceptedVersion, cc-by-nc)
  • Alexandria (UniSG) (University of St.Gallen) (submittedVersion)
  • OSF Preprints (OSF Preprints) (submittedVersion)
  • Repository for Publications and Research Data (ETH Zurich) (submittedVersion, cc-by-nc)
  • Zurich Open Repository and Archive (University of Zurich) (submittedVersion, cc-by-nc)
  • ETH Zürich Research Collection
  • Zurich Open Repository and Archive (University of Zurich)
Funders
CSS Insurance
Topics
  • Health Sciences › Health Professions › General Health Professions › Mobile Health and mHealth Applications
  • Health Sciences › Medicine › Physiology › Physical Activity and Health
  • Social Sciences › Psychology › Applied Psychology › Digital Mental Health Interventions
Keywords
physical activity promotion, financial incentives, cash incentives, action planning, coping planning, app engagement, digital health interventions
MeSH terms
Smartphone, Adult, Female, Goals, Humans, Male, Middle Aged, Motivation, Patient Participation, Random Allocation, Software Design, Switzerland, Exercise, Walking, Reminder Systems, Telemedicine, Mobile Applications

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