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Effective and sustainable implementation of physical activity (PA) in type 2 diabetes (T2D) health care has in general not been successful. Efficacious and contemporary approaches to support PA adherence and adoption are required.
The primary objective of this study was to investigate the effectiveness of including an app-based (InterWalk) approach in municipality-based rehabilitation to increase moderate-and-vigorous PA (MVPA) across 52 weeks compared with standard care among individuals with T2D.
The study was designed as a parallel-group, randomized trial with 52 weeks’ intervention and subsequent follow-up for effectiveness (52 weeks from baseline). Participants were recruited between January 2015 and December 2016 and randomly allocated (2:1) into 12 weeks of (1) standard care + InterWalk app–based interval walking training (IWT; IWT group; n=140), or (2) standard care + the standard exercise program (StC group; n=74). Following 12 weeks, the IWT group was encouraged to maintain InterWalk app–based IWT (3 times per week for 30-60 minutes) and the StC group was encouraged to maintain exercise without structured support. Moreover, half of the IWT group (IWTsupport group, n=54) received additional motivational support following the 12-week program until 52-week follow-up. The primary outcome was change in objectively measured MVPA time (minutes/day) from baseline to 52-week follow-up. Key secondary outcomes included changes in self-rated physical and mental health–related quality of life (HRQoL), physical fitness, weight, and waist circumference.
Participants had a mean age of 59.6 (SD 10.6) years and 128/214 (59.8%) were men. No changes in MVPA time were observed from baseline to 52-week follow-up in the StC and IWT groups (least squares means [95% CI] 0.6 [–4.6 to 5.8] and –0.2 [–3.8 to 3.3], respectively) and no differences were observed between the groups (mean difference [95% CI] –0.8 [–8.1 to 6.4] minutes/day;
Among individuals with T2D referred to municipality-based lifestyle programs, randomization to InterWalk app–based IWT did not increase objectively measured MVPA time over 52 weeks compared with standard health care, although apparent benefits were observed for physical HRQoL.
ClinicalTrials.gov NCT02341690; https://clinicaltrials.gov/ct2/show/NCT02341690
Physical activity (PA) is a cornerstone in the prevention and management of type 2 diabetes (T2D) [
While MVPA is recommended for individuals with T2D [
The increasing implementation of digital solutions in health care [
The primary aim of this study was to test the hypothesis that InterWalk app–based IWT implemented in a municipality-based health care setting is superior in increasing MVPA across 52 weeks compared with standard care among individuals with T2D. Secondarily, we investigated the effects of the intervention on self-rated physical and mental health–related quality of life (HRQoL), physical fitness, weight, and waist circumference. Moreover, we wanted to explore the effects of additional motivational support for InterWalk app–based IWT on these outcomes.
The study was a parallel-group, randomized trial with 52 weeks of intervention and subsequent effectiveness follow-up a year after baseline. All participants provided oral and written informed consent prior to commencing any study procedures. The original protocol has been published [
The study was approved by the scientific ethical committee of the Capital Region of Denmark (H-1-2014-074) and registered at clinicaltrials.gov (NCT02341690).
Inclusion criteria were T2D diagnosis, ≥18 years of age, and referral to a municipality health promotion center or hospital in the participating municipality by the individual’s general practitioner. Exclusion criteria were medical contraindications to exercise, for example, chronic complications in the musculoskeletal system, painful osteoarthritis, or heart conditions [
The data were collected at the participating health promotion centers (Amager, Vanløse, Østerbro, Vesterbro in the Municipality of Copenhagen, Denmark; and Municipality of Guldborgsund, Denmark) and a hospital (Bornholm, Denmark).
Participants were randomly allocated (2:1) into 1 of 2 arms: (1) standard care + InterWalk app–based IWT (IWT group) or (2) standard care + the standard exercise program (StC group). Following the initial 12-week supervised exercise program, the participants in the IWT group were further randomly allocated (1:1) into (1) IWT, no additional support (IWTonly group) or (2) IWT, with additional support (IWTsupport group), that is, participants in the IWTonly group and the IWTsupport group underwent similar interventions during the 12-week exercise program, and allocation to either of these was concealed until after the 12-week intermediate assessment.
Participants were randomized using random permuted blocks stratified by sex (2 levels) and center (6 levels). The allocation sequence was generated through a standardized computer program by an independent statistician (RC) and stored on a password-protected computer by an independent researcher (RN) who was not involved in any study procedures. Following the completion of all baseline measurements, the independent researcher was contacted and performed allocation (to StC or IWTonly or IWTsupport). The respective group allocation for the initial 12 weeks (StC or IWT) was subsequently returned by email to the health professional who informed the participant about the allocation by telephone call. Information about IWTonly or IWTsupport was not disclosed by the independent researcher to the health professionals until week 12. Following the 12-week intermediate assessment, the independent researcher was contacted and the allocation into IWTonly or IWTsupport was returned by email to the health professional who informed the participant about the allocation by telephone call. The health professionals carried through the data collection and intervention, and thus, were only blinded to the primary outcome.
The interventions have been described in detail elsewhere [
As part of normal practice, lifestyle interventions may be prescribed to individuals with T2D by their general practitioner by referral to municipality-based lifestyle programs [
Both the IWT and StC groups underwent 12 weeks of standard municipality-based health care [
Following the initial 12 weeks, the StC group was encouraged to maintain exercise without structured support.
The participants allocated to the InterWalk app–based intervention from baseline to 12-week follow-up were either allocated to be encouraged to maintain InterWalk app–based IWT (3 times per week for 30-60 minutes; IWTonly) until 52-week follow-up or was, for explorative purposes, allocated to additional motivational support following the 12-week program and until the 52-week follow-up (IWTsupport). Feasibility and usability have been described elsewhere [
The motivational interviews were semistructured and performed during weeks 16, 20, 28, and 40 after the baseline assessment. They were designed to structure the communication between the participant and the health professional. The interviews intended to facilitate a partnership formed to reveal and visualize the patients’ motivation and barriers toward the intended behavior change and acknowledgement of patient autonomy [
The ambassador program was a part of a peer-to-peer educational program, where the Danish Diabetes Association offered group walking for all members. The participants were invited to attend these walking groups, where the walking activity was implemented using the InterWalk app.
Finally, facilitation of high adherence to IWT was based on automated feedback to self-reported adherence to IWT using weekly bidirectional SMS text message surveys [
The design and functionality of the InterWalk app was developed in collaboration with persons with T2D using a participatory design. The full details have been described in detail elsewhere [
The app was designed to specifically facilitate IWT through continuous individualized audio feedback. The app guides and paces the user through repeated cycles of 3-minute slow walking and 3-minute fast walking [
Following an IWT session, the objectively measured adherence (intensity, duration, and frequency) to IWT sessions was calculated based on the electronically logged information from the InterWalk app. Data from the InterWalk app were continuously uploaded to a central and secure server throughout the duration of the trial. Self-reported adherence to IWT was calculated based on data from the SMS text message survey, including frequency of weekly use of the InterWalk app and reasons for not using the InterWalk app [
Primary and key secondary outcome measurements are described in further detail in the published protocol [
The primary outcome measure was change in objectively measured MVPA time (minutes/day) from baseline to 52-week follow-up. PA outcomes were assessed using accelerometers (AX3; Axivity) attached to the participants’ thigh and back using an adhesive tape (Fixomull Stretch; BSN Medical Inc.) and worn for 7-10 consecutive days at baseline, 12 weeks, and 52 weeks. Accelerometer setup and download of raw data (100 Hz) and downsampling to 30 Hz were performed using OmGui (version 1.0.0.28) [
Key secondary outcome measures include changes in physical and mental HRQoL, physical fitness (peak oxygen consumption [VO2peak]), self-rated PA energy expenditure (PAEE), exercise motivation, weight, and waist circumference, which were assessed at baseline, 12 weeks, and 52 weeks. Physical and mental HRQoL were assessed using the 12-item Short-Form Health Survey (SF-12), including 8 subscales [
Exploratory secondary outcomes were changes in objectively measured light-intensity PA (100 to <1952 CPM) time (minutes/day), total PA level (CPM), and steps (numbers/day) [
The minimal important difference was considered to be 10 minutes of MVPA per day. Based on existing experimental evidence, we assumed the SD of the change in MVPA time from baseline to 52-week follow-up to be between 1.2 and 2.3 times the difference between groups [
A statistical analysis plan was developed and published at the Centre for Physical Activity Research website prior to commencing the statistical analyses [
To investigate the robustness of the primary analyses, 5 sensitivity analyses were conducted, including 4 analyses of differences in changes in MVPA time from baseline to 52-week follow-up between the IWT group and the StC group: (1) per-protocol analysis, including complete cases of the primary outcome at baseline and 52-week follow-up with ≥70% of the prescribed exercise (3 sessions per week for 52 weeks) completed in the IWT group and no registered IWT sessions in the InterWalk app in the StC group; (2) analysis including all randomized participants with available data at baseline with a conservative single-imputation nonresponder imputation technique (ie, missing data replaced with the baseline observation carried forward); (3) analysis with the subsample of participants not undergoing intervention during a period of InterWalk app malfunctions connected to a major restructuring of the iOS (version 9; available during the period from September 16 to October 21, 2016); and (4) analysis with daytime criteria for inclusion, that is, ≥3 days of ≥14 hours of daytime measurement (6 AM to 22 PM; ie, allowing for 2 hours of nonwear time during this period). In the fifth sensitivity analysis, we used an alternative cut-off at 3000 CPM to investigate changes in forced walking time from baseline to 52-week follow-up between the IWT group and the StC group.
Subgroup analyses were conducted to investigate the effects of IWT versus StC on change in MVPA time (minutes/day) after 52 weeks among subgroups of sex (men/women); T2D duration (≤5 years/>5 years); alcohol consumption (within recommended levels/above recommendations); smoking habits (smoker/nonsmoker); highest level of education (International Standard Classification of Education 2011 [ISCED-2011] levels 0-4/ISCED-2011 levels 5-8); civil status (single, divorced, or widowed/married or cohabiting); baseline SF-12 PCS level (high/low); and baseline SF-12 MCS level (high/low). SF-12 PCS and MCS were divided into high and low using median split. Moreover, differences in median (25th to 75th percentile) duration of IWT (minutes/week) over 52 weeks were investigated among these subgroups.
All reported 95% CIs and
Between January 2015 and December 2016, 762 individuals were screened for inclusion (
The IWT group engaged in IWT with a median (25th-75th percentile) frequency of 0.3 (0.1-0.7) sessions/week for 11.4 (4.1-22.3) minutes/week at a median intensity of 0.17 (0.11-0.23) G (
Participant flowchart.
Demographic and clinical characteristics of participants at baseline (n=214 patients in the intention-to-treat population).a
Demographic and clinical characteristics | StCb group (n=74) | IWTc group (n=140) | Total (n=214) | ||||
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Male | 47 (63.5) | 81 (57.9) | 128 (59.8) | |||
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Female | 27 (36.5) | 59 (42.1) | 86 (40.2) | |||
Age (years) | 59.8 (10.1) | 59.6 (10.8) | 59.6 (10.6) | ||||
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1.7 (0.2-7.0) | 3.0 (0.2-10.0) | 2.6 (0.2-8.6) | ||||
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≤5 years | 45/68 (66.2) | 74/129 (57.4) | 119 (60.4) | |||
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>5 years | 23/68 (33.8) | 55/129 (42.6) | 78 (39.6) | |||
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Within the recommended levels | 69 (93.2) | 129/139 (92.8) | 198 (93.0) | |||
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Above recommendations | 5 (6.8) | 10/139 (7.2) | 15 (7.0) | |||
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Smoker | 20 (27.0) | 29 (20.7) | 49 (22.9) | |||
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Nonsmoker | 54 (73.0) | 111 (79.3) | 165 (77.1) | |||
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ISCED-2011d levels 0-4 | 39 (52.7) | 75/135 (55.6) | 114 (54.5) | |||
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ISCED-2011 levels 5-8 | 35 (47.3) | 60/135 (44.4) | 95 (45.5) | |||
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Single, divorced, or widowed | 36 (48.6) | 64 (45.7) | 100 (46.7) | |||
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Married or cohabiting | 38 (51.4) | 76 (54.3) | 114 (53.3) | |||
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Height (cm; n=212) | 171.7 (9.4) | 172.5 (8.8) | 172.2 (9.0) | |||
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MVPAe time (minutes/day; n=200) | 30.5 (17.3-41.7) | 30.2 (16.6-51.8) | 30.2 (16.9-48.1) | |||
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Sitting time (minutes/day; n=195) | 556.3 (157.5) | 527.3 (162.6) | 537.4 (161.0) | |||
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LPAf time (minutes/day; n=200) | 136.3 (52.5) | 136.0 (48.7) | 136.1 (49.9) | |||
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TPAg level (CPMh; n=200) | 212.9 (141.6-291.0) | 207.6 (137.8-345.2) | 211.5 (140.9-313.8) | |||
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Steps (n/day; n=200) | 4164 (2766-5738) | 4078 (2801-6145) | 4100 (2794-5986) | |||
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VO2peaki (ml O2/minute; n=124) | 1859 (511) | 1763 (469) | 1791 (481) | |||
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SF-12j Physical Component Summary (score 0-100) | 40.3 (10.4) | 41.5 (10.1) | 41.1 (10.2) | |||
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SF-12 Mental Component Summary (score 0-100) | 47.4 (39.6-55.8) | 50.9 (41.3-57.1) | 50.1 (40.1-56.9) | |||
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RPAQk self-rated PAEEl (kJ/kg/day; n=209) | 150.1 (92.5-226.7) | 136.0 (92.9-225.7) | 143.8 (92.9-226.4) | |||
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BREQ-2m RAIn (score –24 to 20) | 7.4 (4.0-10.8) | 7.4 (3.5-11.7) | 7.4 (3.5-11.3) | |||
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Weight (kg; n=212) | 101 (85-119) | 98 (87-113) | 99 (87-115) | |||
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Waist circumference (cm; n=211) | 117.9 (16.0) | 115.3 (12.9) | 116.2 (14.1) | |||
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BMI (kg/m2; n=212) | 34.6 (6.6) | 33.6 (5.3) | 34.0 (5.7) |
aData are presented as median (IQR), mean (SD), n (%), or n/N (%).
bStC: standard care.
cIWT: interval walking training.
dISCED-2011: International Standard Classification of Education 2011.
eMVPA: moderate-and-vigorous physical activity.
fLPA: light-intensity physical activity.
gTPA: total physical activity.
hCPM: counts per minute.
iVO2peak: peak oxygen consumption.
jSF-12: 12-item Short-Form Health Survey.
kRPAQ: Recent Physical Activity Questionnaire.
lPAEE: physical activity energy expenditure.
mBREQ-2: Behavioral Regulation in Exercise Questionnaire-2.
nRAI: Relative Autonomy Index.
No change in MVPA time was observed from baseline to 52-week follow-up within the StC and IWT groups (
Only 5 participants in the IWT group fulfilled the per-protocol criteria and the analysis was thus omitted. The remaining sensitivity analyses supported the primary analysis (
Least squares means (95% CI’s) of MVPA time (min/day) at baseline, 12-week and 52-week follow-up for the IWT and StC group. IWT: interval walking training; MVPA: moderate-and-vigorous physical activity; StC: standard care.
Intention-to-treat analyses of changes from baseline to 52-week follow-up between the IWT group and the StC groupa.
Outcomes | StCb group (n=74) | IWTc group (n=140) | Between-group |
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Difference between means (95% CI) | BHd adjusted |
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MVPAe time (minutes/day; n=200) | 0.6 (–4.6 to 5.8) | –0.2 (–3.8 to 3.3) | –0.8 (–8.1 to 6.4) | .82 | N/Af |
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MVPA respondersg (n=116) | 7/41 (17.1) | 17/75 (22.7) | N/A | NAh | N/A |
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SF-12i PCSj (score 0-100) | 0.0 (–1.9 to 1.8) | 4.3 (3.1 to 5.6) | 4.3 (1.8 to 6.9) | .001 | .007 |
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SF-12 PCS respondersg (n=128) | 15/45 (33.3) | 45/83 (54.2) | N/A | NA | N/A |
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SF-12 MCSk (score 0-100) | 2.6 (0.2 to 5.0) | 1.3 (–0.4 to 2.9) | –1.3 (–4.7 to 2.0) | .43 | .43 |
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SF-12 MCS respondersg (n=128) | 18/45 (40.0) | 31/83 (37.3) | N/A | NA | N/A |
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VO2peakl (ml O2/min; n=54) | 4.0 (–128.0 to 136.0) | 76.3 (5.4 to 147.3) | 72.4 (–102.0 to 246.8) | .42 | .49 |
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RPAQm self-rated PAEEn (kJ/kg/day; n=209) | 8.0 (–15.9 to 31.8) | –8.3 (–24.3 to 7.8) | –16.2 (–49.2 to 16.7) | .33 | .46 |
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BREQ-2o RAIp (score –24 to 20) | 1.3 (–0.3 to 2.8) | 2.6 (1.6 to 3.6) | 1.4 (–0.7 to 3.5) | .20 | .35 |
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Weight (kg; n=212) | –0.1 (–1.3 to 1.1) | –1.6 (–2.3 to –0.8) | –1.4 (–3.1 to 0.2) | .09 | .21 |
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Waist circumference (cm; n=212) | –0.9 (–2.2 to 0.5) | –3.1 (–4.0 to –2.2) | –2.3 (–4.1 to –0.4) | .02 | .06 |
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Sitting time (minutes/day; n=195) | 39.5 (–2.4 to 81.4) | –13.0 (–41.8 to 15.8) | –52.5 (–109.6 to 4.6) | NA | N/A |
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LPAq time (minutes/day; n=200) | –15.9 (–25.6 to –6.2) | –2.9 (–9.6 to 3.7) | 13.0 (–0.5 to 26.4) | NA | N/A |
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TPAr level (CPMs; n=200) | –12.9 (–41.6 to 15.9) | 3.9 (–15.6 to 23.4) | 16.8 (–23.1 to 56.6) | NA | N/A |
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Steps (n/day; n=200) | –439 (–1100 to 222) | 168 (–280 to 616) | 607 (–311 to 1525) | NA | N/A |
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BMI (kg/m2; n=212) | –0.1 (–0.5 to 0.4) | –0.5 (–0.8 to –0.3) | –0.5 (–1.0 to 0.1) | NA | N/A |
aData for the StC and IWT groups are presented as least squares mean (95% CI) or n (%) or n/N (%).
bStC: standard care.
cIWT: interval walking training.
dBH: Benjamini-Hochberg.
eMVPA: moderate-and-vigorous physical activity.
fN/A: not applicable.
gMVPA responders were defined as change in MVPA time ≥10 minutes/day; SF-12 PCS responders were defined as change in SF-12 PCS >3.29 [
hNA: not analyzed.
iSF-12: 12-item Short-Form Health Survey.
jPCS: Physical Component Summary.
kMCS: Mental Component Summary.
lVO2peak: peak oxygen consumption.
mRPAQ: Recent Physical Activity Questionnaire.
nPAEE: physical activity energy expenditure.
oBREQ-2: Behavioral Regulation in Exercise Questionnaire-2.
pRAI: Relative Autonomy Index.
qLPA: light-intensity physical activity.
rTPA: total physical activity.
sCPM: counts per minute.
From baseline to 12- and 52-week follow-up, SF-12 PCS score (ie, physical HRQoL) increased by a mean of 4.3 (95% CI 3.1 to 5.6) points and 4.2 (95% CI 3.0 to 5.4) points, respectively, in the IWT group and remained unchanged in the StC group. Thus, the SF-12 PCS score increased by a mean of 3.7 (95% CI 1.2 to 6.1) points and 4.3 (95% CI 1.8 to 6.9) points (Benjamini–Hochberg adjusted
Waist circumference decreased by a mean of –3.1 (95% CI –4.0 to –2.2) cm from baseline to 52-week follow-up in the IWT group with no change in the StC group (
No differences in the changes in SF-12 MCS (mental HRQoL), VO2peak, RPAQ self-rated PAEE, BREQ-2 RAI, and weight from baseline to 12- and 52-week follow-up, respectively, were observed between the groups (
Among the exploratory secondary outcomes, no between-group differences were observed from baseline to 12- and 52-week follow-up, except for light-intensity physical activity time and steps that increased from baseline to 12-week follow-up by a mean of 20.1 (95% CI 7.5 to 32.7) minutes/day and 1124 (95% CI 255 to 1992) steps/day, respectively, more in the IWT group compared with the StC group (
From baseline to 52-week follow-up, there were no differences between the IWTonly and IWTsupport groups in the changes in primary, key secondary, and exploratory secondary outcomes (
Forest plot of overall and subgroup effects of IWT vs. StC on change in MVPA time (min/day) after 52 weeks. Subgroup effects include sex (men/women), type 2 diabetes duration (≤5 years/>5 years), alcohol consumption (within the recommended levels/above recommendations), smoking habits (smoker/nonsmoker), highest level of education (ISCED-2011 levels 0-4/ISCED-2011 levels 5-8), civil status (single, divorced or widowed/married or cohabiting), SF-12 PCS (high/low), and SF-12 MCS (high/low), assessed at baseline. ISCED: International Standard Classification of Education; IWT: interval walking training; MCS: Mental Component Summary; PCS: Physical Component Summary; SF-12: 12-item Short-Form Health Survey; StC: standard care; T2D: type 2 diabetes.
No adverse events or harms were reported to the health professionals.
The main finding of this study was that InterWalk app–based IWT did not increase objectively measured MVPA time over 52 weeks compared with standard care among individuals with T2D referred to municipality-based lifestyle programs. While InterWalk app–based IWT resulted in improvements in physical HRQoL and nonsignificant reduction in waist circumference compared with StC, no effects were observed in mental HRQoL, physical fitness, or weight. A key objective of this study was to support individuals with T2D in maintaining PA levels after a 12-week municipality-based exercise program with minimal direct support from health professionals. In general, IWT adherence was low across 52 weeks, largely explaining the lacking effect on MVPA time. During the 12-week exercise program, IWT adherence was remarkably higher and MVPA time increased by >10% from baseline (by 3.6 minutes/day from 30.2 minutes at baseline), indicating that InterWalk app–based IWT potentially contributed to increased MVPA time. The discrepancy of the IWT adherence observed in this and previous IWT studies among individuals with T2D indicates that InterWalk app–based IWT may not—in the present circumstances—be feasible for maintaining PA level after a municipality-based exercise program [
In line with previous studies, adherence to the exercise intervention decreased over time [
In line with this study, previous studies have observed decreased waist circumference [
Limitations of this study include the high loss to follow-up corresponding to 39% at 52 weeks and the low adherence to the intervention. As indicated by the high adherence levels in previous IWT studies among individuals with T2D [
In conclusion, among individuals with T2D referred to municipality-based lifestyle programs, randomization to InterWalk app–based IWT did not increase objectively measured MVPA time over 52 weeks compared with standard care, although an improvement in physical HRQoL was observed. Moreover, in this municipality-based setting, adherence to the intervention was low even when additional motivational support was provided. Further research is needed to identify optimal implementation of digital support for PA adherence and adoption among individuals with T2D.
Statistical analysis plan.
Accelerometer wear time and nonwear time at baseline, 12-week, and 52-week follow-up.
Graph of mean (SD) intensities (per minute) of all registered IWT sessions in the IWT group (ie, IWTonly + IWTsupport).
Adherence to the intervention in the IWT combined (IWTsupport + IWTonly), IWTonly and IWTsupport groups.
Overview of adherence to the follow-up motivational interviews for the IWT support group.
Intention-to-treat analysis of changes from baseline to 12-week intermediate assessment between the IWT group and the StC group.
Sensitivity analyses of changes in MVPA time from baseline to 52-week follow-up between the IWT group and the StC group: (1) Per-protocol analysis; (2) Analysis with non-responder (baseline observation carried forward; BOCF) imputation; (3) Analysis with the subsample of participants whose intervention period did not overlap time of technological malfunction of the InterWalk application; and (4) Analysis with daytime criteria for accelerometer data (ie, ≥3 days of ≥14 h of daytime measurement (6 am to 22 pm)). (5) Sensitivity analysis of changes in forced walking (ie, ≥3000 CPM) time from baseline to 52-week follow-up between the IWT group and the StC group.
Post hoc linear regression analysis of the dose response association over 52 weeks between (a) change in MVPA (min/day) and change in SF-12 PCS score; (b) IWT duration (min/week) and change in SF-12 PCS score; (c) change in MVPA (min/day) and change in waist circumference (cm); and (d) IWT duration (min/week) and change in waist circumference (cm).
Intention-to-treat analysis of changes from baseline to 52-week follow-up between the IWTonly group and the IWTsupport group.
Bar chart of median (25th; 75th percentile) IWT duration (min/week) over 52 weeks among IWT subgroups of sex (men/women), type 2 diabetes duration (≤5 years/>5 years), alcohol consumption (within the recommended levels/above recommendations), smoking habits (smoker/nonsmoker), highest level of education (ISCED-2011 levels 0-4/ISCED-2011 levels 5-8), civil status (single, divorced, or widowed/married or cohabiting), SF-12 PCS (high/low), and SF-12 MCS (high/low), assessed at baseline.
Baseline demographic and clinical characteristics among attenders and nonattenders at 52-week follow-up.
CONSORT-eHEALTH checklist (V 1.6.1).
Behavioral Regulation in Exercise Questionnaire-2
counts per minute
health-related quality of life
International Standard Classification of Education
interval walking training
light-intensity physical activity
least square
Mental Component Summary
moderate-and-vigorous physical activity
physical activity
physical activity energy expenditure
Physical Component Summary
Relative Autonomy Index
Recent Physical Activity Questionnaire
12-item Short-Form Health Survey
standard care
type 2 diabetees
total physical activity
peak oxygen consumption
Participants and health professionals at the centers and hospital are acknowledged for their contribution to data collection and carrying through the interventions. Cecilie Fau Brinkløv and Malte Kongstad are acknowledged for their significant contributions to the study. The InterWalk app uses the REDCap facility at OPEN, Open Patient Data Explorative Network, Odense University Hospital, Region of Southern Denmark to collect data. The Centre for Physical Activity Research (CFAS) is supported by TrygFonden (grants IDs 101390, 20045, and 125132). During the study period, the Centre of Inflammation and Metabolism (CIM) was supported by a grant from the Danish National Research Foundation (DNRF55). CIM/CFAS is a member of DD2—the Danish Center for Strategic Research in Type 2 Diabetes (the Danish Council for Strategic Research, grant numbers 09-067009 and 09-075724). The study was further supported by TrygFonden, Augustinus Fonden, the Foundation for Prevention, and the Foundation for Intersectorial Research Projects. LSV was supported by a grant from the Municipality of Copenhagen, Denmark and The Danish Physiotherapist Foundation. MR-L was supported by a postdoctoral grant from the Danish Diabetes Academy supported by the Novo Nordisk Foundation and The Vissing Foundation. RC (the Parker Institute, Bispebjerg and Frederiksberg Hospital) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). HL was supported by a professor grant from the Municipality of Copenhagen, Denmark. The study funders were not involved in the design of the study; the collection, analysis, and interpretation of data; writing the report; and the decision to submit the paper for publication.
LSV, BKP, HL, and MR-L designed the trial and CB, JSN, KK, IKT, and AAV contributed to the trial design. IKT and LSV collected the data together with the staff at CFAS (Copenhagen, Denmark) and the participating centers and hospital. CG, JCB, and RN contributed with expert knowledge and competences. IKT, YY, RC, and MR-L planned the statistical analyses, which were conducted by IKT. IKT wrote the first draft of the manuscript. IKT and MR-L are guarantors of this work and, as such, had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
None declared.