Impact of Ecological Momentary Assessment Participation on Short-term Smoking Cessation: Results from the quitSTART EMA Incentivization Trial (Preprint)

Cigarette smoking is the leading cause of preventable mortality in the United States. Cessation interventions delivered through smartphone apps can reach large populations of individuals who smoke. Ecological momentary assessment (EMA), a feature often included in existing cessation apps, can be used to track behaviors and other important constructs and to inform just-in-time interventions. However, the isolated influence of EMA engagement on smoking cessation is unknown. In addition, the implications of incentivizing the use of EMA for cessation outcomes are currently unknown. The National Cancer Institute's publicly available smoking cessation app, quitSTART, includes a 2-week voluntary EMA protocol (42 total EMA prompts), which provides an opportunity to explore the impact of EMA incentivization on smoking cessation. This study aimed to examine the influence of app-based EMA participation on smoking cessation for people who are incentivized to use EMA compared with those who are not incentivized (representing the current implementation of EMA within quitSTART). In total, 152 US adults were recruited from web, social media, and SMS text message sources into a randomized controlled trial. All eligible participants were randomized to either nonincentivized EMA or incentivized EMA. Participants completed baseline, 2-week, and 4-week assessments. The primary outcome of interest was 7-day point prevalence abstinence measured at 2 and 4 weeks after app download. Average EMAs completed by arm were compared using a t test. Firth logistic regression modeling was used to determine the association between arm and smoking abstinence at 2 and 4 weeks, adjusted for smoking frequency and concurrent use of other tobacco products. The mean number of EMAs completed was 13.3 (range 0-40, SD 11.2) in the incentivized arm and 4.7 (range 0-28, SD 5.8) in the nonincentivized arm (P<.001). Cessation rates were 9% and 20.3% at 2 weeks (P=.06), and 17.5% and 36.6% at 4 weeks (P=.01) in the incentivized arm and nonincentivized arm, respectively. Study arm was not associated with cessation in the adjusted models (adjusted odds ratio [OR] at 2 weeks 0.60, 95% CI 0.21-1.73; adjusted OR at 4 weeks 0.51, 95% CI 0.22-1.19). This study attempted to isolate and examine the effect of incentivizing EMA engagement on smoking cessation success for adults using a smartphone app to quit. While participants randomized to incentivization of EMA showed higher engagement with this feature, our findings suggest that there was no additional short-term cessation benefit from this engagement. Crude analyses found a potential benefit for allowing autonomy over the use of app features, despite the ability of EMA completion to provide real-time, tailored cessation support.