App Use and Abstinence Outcomes: The Moderating Role of Sociodemographic Variables in a Psychological Intervention to Quit Smoking

<i>Background:</i> App use is related to smoking cessation outcomes in mobile-based interventions but studies that examine its impact on traditional interventions combined with an app are still scarce. Moreover, the interplay between app use and participants’ sociodemographic characteristics remains unexplored, particularly in blended smoking cessation interventions. <i>Objectives:</i> The study aims to explore the main effect of app use and the interactive effect of this variable and sociodemographic variables on abstinence outcomes. The sample composed of 102 participants (M_age= 44.96, SD= 9.97; 57.8% female) who received a psychological cognitive-behavioral smoking cessation intervention combined with the “Non Fumo” app. The Mann–Whitney U-test was used to examine differences in app use according to the smoking status at the end of the intervention, and moderation analyses were conducted to examine the interaction between app use and sociodemographic variables. <i>Results:</i> Results showed that abstinent participants, compared to participants who smoke, used the “Non Fumo” app significantly more. However, app use did not predict abstinence at the end of treatment. Regarding moderation analyses, younger participants with greater app use were more likely to achieve abstinence at the end of the treatment compared to older participants. <i>Conclusions/Importance:</i> This study suggests that the association between app use and cessation outcomes could vary according to specific sociodemographic variables. Findings highlight the relevance of further investigating the relationship between personal characteristics and tobacco outcomes in app-based interventions. This would allow tailoring interventions according to individual characteristics to improve their effectiveness.