Intersectionality in cigarette smoking cessation: A latent class analysis to predict 12-month cessation in a randomized controlled trial.

Abstract

Background and aims: Currently, smoking cessation intervention research on marginalized populations focuses on a single attribute (e.g. race). However, these attributes intersect and research on this intersectionality has been rare. This study applied latent class analysis (LCA) to examine how multiple theory-driven baseline factors interact and predict 12-month 30-day point prevalence abstinence from cigarette smoking in 2415 adult participants in a digital smoking cessation intervention.

Design: Theory-based analysis of a randomized trial with 12-month smoking cessation follow-up.

Setting: United States (US).

Participants: A total of 2415 adults who smoke that were recruited from all 50 US states and enrolled in the trial between May 2017 and September 2018.

Intervention and comparator: In the parent RCT, participants were randomized to receive iCanQuit, an Acceptance and Commitment Therapy-based smartphone smoking cessation app (n = 1214) or QuitGuide, a US Clinical Practice Guidelines-based smoking cessation app (n = 1201) for 12 months.

Measurements: Guided by Sheffer et al.,six theory-based factors were examined, including social identities: gender, race and ethnicity, marital status, sexual and gender minority (SGM) identity and socio-economic status (SES; education, income, employment); and lived experiences: positive screen for experiencing depression symptoms. Social identity and lived experiences data were collected via baseline questionnaires. The primary smoking cessation outcome was self-reported complete-case 30-day point prevalence abstinence at 12 months. SAS PROC LCA was used to identify classes based on the six selected factors and to predict 12-month smoking cessation.

Findings: A 4-class model showed the best goodness-of-fit statistics and interpretability. Participants in class 1 (n = 352, 14.6%) were more likely to be women, individuals of Black race and those with single marital status. Participants in class 2 (n = 322, 13.3%) were more likely to be men, SGM individuals and socioeconomically advantaged, as indicated by higher education, higher income or employment. Participants in class 3 (n = 368, 15.2%) were socioeconomically disadvantaged and screened positive for experiencing depression symptoms at baseline (CES-D $\ge$ 16). Finally, participants in class 4 (n = 1373, 56.9%) were more likely to be women, individuals of White race and married. Class 2 had the highest smoking cessation rate (32.8%) at 12 months, followed by class 1 (27.3%), class 4 (24.2%) and class 3 (15.4%). Compared with class 2, class 3 had 63% lower odds of quitting smoking (odds ratio = 0.37; 95% confidence interval = 0.20-0.71, P = 0.016).

Conclusions: People with both socioeconomic disadvantage and symptoms of depression appear to have a harder time quitting smoking than other people who try to quit.