Factors associated with the efficacy of smoking cessation treatments and predictors of smoking abstinence in EAGLES

Abstract

AimsTo assess (1) how far the efficacies of front‐line smoking cessation pharmacotherapies vary as a function of smoker characteristics and (2) associations between these characteristics and success of smoking cessation attempts.DesignProspective correlational study in the context of a double‐blind randomized trial. The outcome was regressed individually onto each covariate after adjusting for treatment, and then a forward stepwise model constructed. Treatment moderator effects of covariates were tested by treatment × covariate interactions.SettingHealth service facilities in multiple countries.ParticipantsData came from 8120 smokers willing to make a quit attempt, randomized to varenicline, bupropion, nicotine replacement therapy (NRT) or placebo in Evaluating Adverse Events in a Global Smoking Cessation Study (EAGLES) between 30 November 2011 and 13 January 2015.MeasurementsSmoker characteristics measured at baseline were country, psychiatric history, sex, age, body mass index (BMI), ethnic group, life‐time suicidal ideation/behaviour, anxiety, depression, aggression, psychotropic medication, history of alcohol/substance use disorder, age of starting smoking, cigarette dependence [Fagerström Test for Cigarette Dependence (FTCD)] and prior use of study medicines. Outcome was biochemically confirmed continuous abstinence at weeks 9–24 from start of treatment.FindingsNo statistically significant treatment × covariate interactions were found. Odds of success were associated independently positively with age [odds ratio (OR) = 1.01; 95% confidence interval (CI) = 1.00, 1.01], BMI (1.01; 95% CI = 1.00, 1.02) and age of starting smoking (1.03; 95% CI = 1.02, 1.04). Odds were associated independently negatively with US (versus non‐US) study site (0.53; 95% CI = 0.46, 0.61), black (versus white) ethnic group (0.57; 95% CI = 0.45, 0.72), mood disorder (0.85; 95% CI = 0.73, 0.99), anxiety disorder (0.71; 95% CI = 0.55, 0.90) and psychotic disorder (0.73; 95% CI = 0.50, 1.07), taking psychotropic medication (0.81; 95% CI = 0.68, 0.95), FTCD (0.89; 95% CI = 0.87, 0.92) and previous use of NRT (0.78; 95% CI = 0.67, 0.91).ConclusionsWhile a range of smoker characteristics—including psychiatric history, cigarette dependence and prior use of nicotine replacement therapy (NRT)—are associated with lower cessation rates, they do not substantially influence the efficacy of varenicline, bupropion or NRT.

Safety and efficacy of first-line smoking cessation pharmacotherapies in bipolar disorders: Subgroup analysis of a randomized clinical trial

“…The mechanisms through which smokers with BD experience worse cessation outcomes and greater likelihood of NPSAEs requires additional study. Candidate mechanisms include differences highlighted in the present study results (e.g., for the BD subcohort, more severe nicotine dependence on the FTCD, which was predictive of poorer cessation outcomes in the broader study (West et al, 2018); higher baseline levels of anxiety, depression, aggression; and greater likelihood of past suicidal ideation and behavior), as well as the potential influence of some psychotropic medications on nicotine metabolism among smokers with BD (Williams et al, 2012), which may impact pharmacotherapy response (Lerman et al, 2015;Schnoll et al, 2009). Improved understanding of mechanisms underlying greater cessation difficulty and NPSAE occurrence among smokers with BD can help to inform new treatment approaches to address disparities in treatment outcomes.…”

“…We also note that inferences about the quit rates for the NPC in this analysis (n = 2794) should be tempered by the fact that this is a subgroup of the NPC in the larger EAGLES trial (N = 4028) that excludes a significant portion of the non-US participants. Because quit rates were lower for US smokers in EAGLES (West et al, 2018), this led to a decrease in the quit rates for the NPC group in this subgroup analysis since a larger proportion of the sample was from the US (68% in this analysis versus 47% in the larger trial).…”

Varenicline: mode of action, efficacy, safety and accumulated experience salient for clinical populations

“…Similarly, CAR9-24 and CAR9-52 were significantly higher for varenicline than placebo (CAR9-24: 28.9% vs. 7.8%; OR, 5.83; 95% CI: 3.25, 10.44; CAR9-52: 20.1% vs. 3.3%, OR, 9.00; 95% CI: 3.97, 20.41). Consistent with these findings, post-hoc analyses of EAGLES found no evidence of a moderator effect of prior treatment on the success of a new quit attempt with varenicline 63 .…”

Factors Associated With Abstinence After a Recent Smoking Cessation Attempt Across 28 European Union Member States

“…Existing tobacco control policies have been found to be most effective in higher SES groups [9], and having access to healthcare and therefore medical advice and cessation assistance through insurance, is also associated with higher likelihood of successful cessation [5]. In addition, lower odds of success have been demonstrated in high levels of nicotine dependence [7,37], poorer mental health [38,39] and living in a home that permitted smoking [5], all of which are conditions that are more likely amongst smokers in lower SES groups [40]. These factors would be an important area for future research assessing associations with successful cessation, but had not been included in our study as they were beyond the scope of our data set.…”