JMIR Publications

ABSTRACT

Background:

Efficacy of smartphone-based interventions depends on intervention content quality and level of exposure to content. Smartphone-based survey completion rates tend to decline over time; however, few studies have identified variables that predict this decline over longer-term interventions (e.g., 26 weeks). The objective of the study is to assess the predictors of survey completion and message viewing over time within a 26-week smoking cessation trial. This study examined data from a three-group pilot randomized controlled trial of adult smokers (N=152) who were unready to quit smoking within the next 30 days. For 182 days, two intervention groups received smartphone-based morning and evening messages based on current readiness to quit smoking. The control group received two daily messages unrelated to smoking. All participants were prompted to complete 26 weekly smartphone-based surveys. Compliance was operationalized as percentages of weekly surveys completed and daily messages viewed. Linear regression and mixed-effects models were used to identify predictors (e.g., intervention group, age, sex) of weekly survey completion and daily message viewing and decline in compliance over time. Participants (Mage=50) were 67.8% female, 74.3% white, 77% urban, and 52.6% unemployed. Age was positively associated with overall weekly survey completion (p=0.003) and daily message viewing (p=0.018). Mixed-effects models indicated a decline in survey completion across time (p<0.0001), which was significantly moderated by age, sex, ethnicity, municipality (i.e., rural/urban), and employment status. Similarly, message viewing declined across time (p<0.0001), and was significantly moderated by age, sex, municipality, employment status, and education. Future research should identify ways to maintain high levels of interaction with mHealth interventions that span long intervention periods, especially among subgroups with lower rates of intervention engagement.

Objective:

The objective of the study is to assess the predictors of survey completion and message viewing over time within a 26-week smoking cessation trial.

Methods:

This study examined data from a three-group pilot randomized controlled trial of adult smokers (N=152) who were unready to quit smoking within the next 30 days. For 182 days, two intervention groups received smartphone-based morning and evening messages based on current readiness to quit smoking. The control group received two daily messages unrelated to smoking. All participants were prompted to complete 26 weekly smartphone-based surveys. Compliance was operationalized as percentages of weekly surveys completed and daily messages viewed. Linear regression and mixed-effects models were used to identify predictors (e.g., intervention group, age, sex) of weekly survey completion and daily message viewing and decline in compliance over time.

Results:

Participants (Mage=50) were 67.8% female, 74.3% white, 77% urban, and 52.6% unemployed. Age was positively associated with overall weekly survey completion (p=0.003) and daily message viewing (p=0.018). Mixed-effects models indicated a decline in survey completion across time (p<0.0001), which was significantly moderated by age, sex, ethnicity, municipality (i.e., rural/urban), and employment status. Similarly, message viewing declined across time (p<0.0001), and was significantly moderated by age, sex, municipality, employment status, and education.

Conclusions:

Future research should identify ways to maintain high levels of interaction with mHealth interventions that span long intervention periods, especially among subgroups with lower rates of intervention engagement.