Effect and acceptability of an mHealth smoking cessation intervention 'Stopcoach' combined with smoking cessation counseling for people from multiple levels of socioeconomic position: a multi-methods study.

Introduction: Smoking cessation interventions tend to be less effective for people of lower socioeconomic position (SEP) compared to those of higher SEP. Mobile phone-based interventions have been shown to increase abstinence from smoking. Stopcoach is an mHealth smoking cessation intervention that specifically targets people with a lower SEP. A pilot study showed the potential and feasibility of Stopcoach but as yet no research exists that assesses the effectiveness of Stopcoach.

Objective: This study aims to evaluate whether using Stopcoach in combination with group-based smoking cessation counselling (SCC; intervention group) increases short- and long-term abstinence compared to SCC alone (control groups). Secondarily, this study aims to assess acceptability of Stopcoach as perceived by people who smoke and SCC group coaches.

Methods: This multi-methods study was originally designed comparing an intervention group (n = 242; 2020-2022) to a historical control group (n = 3362; 2018-2020) that did not use Stopcoach. However, the COVID-19 pandemic hampered realistic comparison due to declining abstinence rates. Therefore, a COVID-era control group was added (n = 312; 2020-2021). All participants enrolled in professionally led SCC groups. The primary outcome was abstinence at four weeks and one year after quit date. In the intervention group, usability, acceptability and usefulness were also measured. In a qualitative assessment, eight SCC trainers were interviewed to explore acceptance by trainers and integration of Stopcoach into SCC.

Results: Due to the COVID-19 related overall decline in abstinence rates, the intervention group had lower abstinence rates compared to the pre-COVID control group (73.6% vs. 78.2% p < 0.001). However, the COVID-era control group revealed that Stopcoach, as addition to accredited SCC, was associated with higher abstinence rates after four weeks than SCC alone (73.6% vs. 57.1%, p < 0.001). This difference was sustained in the lower SEP subgroup (65.6% vs. 49.6%, p = 0.043). No overall significant differences in 1-year abstinence rates were found between the intervention group and both control groups. Participants rated usability, acceptability and usefulness highly positive, irrespective of SEP. Qualitative measures showed most trainers welcomed adding Stopcoach to their SCC.

Conclusion: Addition of the Stopcoach app to SCC appears effective and feasible. Importantly, this also holds for the lower SEP subgroup. This makes Stopcoach one of the few smoking cessation mHealth interventions that also meets the needs of people with lower SEP who smoke.