JMIR Publications

ABSTRACT

Background:

Cardiac rehabilitation participants are encouraged to meet the public health physical activity guidelines to reduce the risk of repeat cardiac events. However, studies have found that their physical activity levels are low and sedentary behavior is high, both during and after cardiac rehabilitation. There is potential for smartphone apps to be effective in reducing sedentary behavior, although few studies have investigated smartphone apps in cardiac rehabilitation, and none appear to target sedentary behavior.

Objective:

To evaluate the feasibility of a behavioral smartphone app (Vire) and online behavior change program (ToDo-CR) to decrease sedentary behavior in cardiac rehabilitation participants.

Methods:

Using a single-center pre-post design, participants were recruited by nursing staff on-entry into cardiac rehabilitation. All eligible participants installed the Vire app, were given a Fitbit Flex and received the 6-week ToDo-CR program while attending cardiac rehabilitation. The ToDo-CR program uses personalized analytics to interpret important behavioral aspects (physical activity, situational context and social opportunity). The program uses real-time information for generating and suggesting context specific actionable micro behaviors (Do’s). Do’s are delivered via the app, with participants receiving 14-19 Do’s during the 6-week intervention period. Outcome measures were collected at 0, 6 and 16-weeks. Assessors were not blinded. Feasibility outcomes included recruitment and follow-up rates, resource requirements, app usability (UTAUT2 questionnaire) and efficacy to detect a change in objectively-measured daily minutes of sedentary behavior (ActiGraph ActiSleep). Secondary outcomes included functional aerobic capacity (6-minute walk test), quality-of-life (MacNew questionnaire), anxiety and depression (Hospital Anxiety and Depression Scale questionnaire), body mass index, waist circumference, waist-to-hip ratio and blood pressure.

Results:

Between January to May 2019, 20 participants were consecutively recruited. One third of people commencing cardiac rehabilitation were eligible to participate. Other than declining to take part in the study (38%), not having a smartphone was a major reason for exclusion (28%). Those excluded without a smartphone were significantly older than participants with a smartphone (mean difference 20 years, p<0.001). Participants were on average 55 years old, mostly male (85%) and working (67%). At 6-weeks 95% of participants were assessed, and 60% of participants were assessed at 16-weeks. Participants were relatively satisfied with the usability of the app (UTAUT2 questionnaire). Objectively-measured daily minutes of sedentary behavior did not change significantly over the study period, and participants spent 11-12 hours per day sitting. Although, there was a non-significant decrease in percentage of the day spent sitting at 16-weeks, with a small effect size (68.2% vs 65.7%, P=0.15, Cohen’s d=0.33).

Conclusions:

The use of a behavioral smartphone app to decrease sitting time appears to be feasible in cardiac rehabilitation. A larger randomized controlled trial is warranted to determine the effectiveness of the app. Clinical Trial: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12617001429347, http://www.ANZCTR.org.au/ACTRN12617001429347.aspx, date registered: 9 October 2017.