Predicting Outcomes from Engagement With Specific Components of an Internet-Based Physical Activity Intervention With Financial Incentives: Process Analysis of a Cluster Randomized Controlled Trial

Abstract

Background Investigating participant engagement and nonusage attrition can help identify the likely active ingredients of electronic health interventions. Research on engagement can identify which intervention components predict health outcomes. Research on nonusage attrition is important to make recommendations for retaining participants in future studies. Objective This study aimed to investigate engagement and nonusage attrition in the Physical Activity Loyalty (PAL) scheme, a 6-month complex physical activity intervention in workplaces in Northern Ireland. The intervention included financial incentives with reward redemption and self-regulation techniques. Specific objectives were (1) to determine whether engagement in specific intervention components predicted physical activity at 6 months, (2) to determine whether engagement in specific intervention components predicted targeted mediators at 6 months, and (3) to investigate predictors of nonusage attrition for participants recording daily activity via the PAL scheme physical activity monitoring system and logging onto the website. Methods Physical activity was assessed at baseline and 6 months using pedometers (Yamax Digiwalker CW-701, Japan). Markers of engagement and website use, monitoring system use, and reward redemption were collected throughout the scheme. Random-effects generalized least-squares regressions determined whether engagement with specific intervention components predicted 6-month physical activity and mediators. Cox proportional hazards regressions were used to investigate predictors of nonusage attrition (days until first 2-week lapse). Results A multivariable generalized least-squares regression model (n=230) showed that the frequency of hits on the website’s monitoring and feedback component (regression coefficient [ b ]=50.2; SE=24.5; P =.04) and the percentage of earned points redeemed for financial incentives ( b =9.1; SE=3.3; P =.005) were positively related to 6-month pedometer steps per day. The frequency of hits on the discussion forum ( b =−69.3; SE=26.6; P =.009) was negatively related to 6-month pedometer steps per day. Reward redemption was not related to levels of more internal forms of motivation. Multivariable Cox proportional hazards regression models identified several baseline predictors associated with nonusage attrition. These included identified regulation (hazard ratio [HR] 0.88, 95% CI 0.81-0.97), recovery self-efficacy (HR 0.88, 95% CI 0.80-0.98), and perceived workplace environment safety (HR 1.07, 95% CI 1.02-1.11) for using the physical activity monitoring system. The EuroQoL health index (HR 0.33, 95% CI 0.12-0.91), financial motivation (HR 0.93, 95% CI 0.87-0.99), and perceived availability of physical activity opportu...

Mechanisms of physical activity behavior change in an incentive-based intervention: Mediation analysis.

“…Contrary to hypotheses proposed by self-determination theory (Deci et al, 1999), which have been supported by the results of previous laboratory-based studies (Promberger & Marteau, 2013), the present findings show that intrinsic motivation has not been adversely impacted by the provision of financial incentives (i.e. extrinsic rewards) in line with the study's process analysis (Murray et al, 2019). Correlation matrices shown in additional file 2 confirm that there was no significant relationship between financial motivation and identified regulation, integrated regulation or intrinsic motivation.…”

A loyalty scheme to encourage physical activity in office workers: a cluster RCT

“…The multivariable analysis for website use showed that being older (hazard ratio 0.99, 95% CI 0.98 to 1.00), unmarried/not co-habiting (hazard ratio 0.79, 95% CI 0.63 to 1.00), having higher values on the EuroQol (EQ-5D) weighted health index (hazard ratio 0.32, 95% CI 0.12 to 0.86), having higher levels of financial motivation at baseline (hazard ratio 0.93, 95% CI 0.87 to 0.99), having a lower perception of the attractiveness of the workplace environment for PA at baseline (hazard ratio 1.06, 95% CI 1.01 to 1.11), or having a higher perception of the availability of PA opportunities in the workplace environment at baseline (hazard ratio 0.94, 95% CI 0.90 to 0.98) reduced the risk of attrition. 134 under the Creative Commons Attribution (CC-BY) 4.0 (https:// creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially. 134 under the Creative Commons Attribution (CC-BY) 4.0 (https://creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially.…”

“…134 under the Creative Commons Attribution (CC-BY) 4.0 (https:// creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially. 134 under the Creative Commons Attribution (CC-BY) 4.0 (https://creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially. 134 under the Creative Commons Attribution (CC-BY) 4.0 (https://creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially.…”

“…134 under the Creative Commons Attribution (CC-BY) 4.0 (https://creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially. 134 under the Creative Commons Attribution (CC-BY) 4.0 (https://creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially.…”

“…Number of sections accessed on the website at least once was a significant predictor of identified regulation (b = 0.07, SE 0.02; p < 0.01) and integrated regulation (b = 0.09, SE 0.03; p < 0.01). 134 under the Creative Commons Attribution (CC-BY) 4.0 (https://creativecommons.org/licenses/by/4.0/) licence, which allows to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially.…”