Treatment adherence in a smoking cessation clinical trial for individuals with current or past major depressive disorder: Predictors and association with cessation.

INTRODUCTION: Individuals with major depressive disorder (MDD) exhibit high rates of tobacco use and lower responsiveness to tobacco cessation treatments. Treatment adherence is a strong predictor of treatment outcomes in the general population but has not been evaluated in this under-served community of smokers with MDD. METHODS: We used data from a randomized clinical trial on smoking cessation treatment among 300 smokers with MDD to examine the rate of adherence (medication and counseling), the association of adherence with cessation outcomes, and factors associated with adherence, including demographic and smoking characteristics, psychiatric characteristics, smoking cessation processes (e.g., withdrawal, reinforcers), and treatment-related side effects (e.g., nausea). RESULTS: Overall, 43.7% of participants were adherent with medication and 63.0% were adherent with counseling. Medication adherence was significantly associated with cessation, with 32.1% of adherent vs. 13.0% of non-adherent participants quitting smoking at EOT. Counseling adherence was also significantly associated with cessation, with 32.3% of adherent vs. 2.7% of non-adherent participants quitting smoking. Multivariate regression models showed that medication adherence was associated with higher engagement in complementary reinforcers and higher baseline smoking reward, while counseling adherence was associated with identifying as female, lower alcohol use and nicotine dependence, higher baseline smoking reward, and higher engagement in substitute and complementary reinforcers within the first weeks of medication use. CONCLUSIONS: As with the general population of smokers, non-adherence to treatment in smokers experiencing depression is widespread and a significant barrier to cessation. Interventions that target reinforcers may improve rates of treatment adherence.

Medication adherence and rate of nicotine metabolism are associated with response to treatment with varenicline among smokers with HIV.

INTRODUCTION: PLWHA who smoke have shown lower cessation rates within placebo-controlled randomized trials of varenicline. Adherence and rate of nicotine metabolism may be associated with quit rates in such clinical trials. METHODS: This secondary analysis of a randomized placebo-controlled trial of varenicline for smoking among PLWHA (N = 179) examined the relationship between varenicline adherence (pill count, ≥80% of pills), nicotine metabolism (based on the nicotine metabolite ratio; NMR) and end-of-treatment smoking cessation (self-reported 7-day point prevalence abstinence, confirmed with carbon monoxide of ≤ 8 ppm, at the end of treatment; EOT). RESULTS: Combining varenicline and placebo arms, greater adherence (OR = 1.011, 95% CI:1.00-1.02, p = 0.051) and faster nicotine metabolism (OR = 3.08, 95% CI:1.01-9.37, p = 0.047) were related to higher quit rates. In separate models, adherence (OR = 1.009, 95% CI:1.004-1.01, p < 0.001) and nicotine metabolism rate (OR = 2.04, 95% CI:1.19-3.49, p = 0.009) interacted with treatment arm to effect quit rates. The quit rate for varenicline vs. placebo was higher for both non-adherent (19% vs. 5%; χ2[1] = 2.80, p = 0.09) and adherent (35% vs. 15%; χ2[1] = 6.51, p = 0.01) participants, but the difference between treatment arms was statistically significant only for adherent participants. Likewise, among slow metabolizers (NMR < 0.31), the varenicline quit rate was not significantly higher vs. placebo (14% vs. 5%; χ2[1] = 1.17, p = 0.28) but, among fast metabolizers (NMR ≥ 0.31), the quit rate for varenicline was significantly higher vs. placebo (33% vs. 14%; χ2[1] = 4.43, p = 0.04). CONCLUSIONS: Increasing varenicline adherence and ensuring that fast nicotine metabolizers receive varenicline may increase quit rates for PLWHA.

Assessing barriers to providing tobacco use disorder treatment in community mental health settings with a revised version of the Smoking Knowledge, Attitudes, and Practices (S-KAP) instrument.

BACKGROUND: Tobacco use disorder (TUD) rates are 2-3 times higher among people with serious mental illness (SMI) than the general population. Clinicians working in outpatient community mental health clinics are well positioned to provide TUD treatment to this group, but rates of treatment provision are very low. Understanding factors associated with the provision of TUD treatment by mental health clinicians is a priority. METHODS: This study used baseline data from an ongoing cluster-randomized clinical trial evaluating two approaches to training clinicians to increase TUD treatment. Following a psychometric assessment of our assessment tool, the Smoking Knowledge, Attitudes, and Practices (S-KAP) instrument, a new factor structure was evaluated utilizing confirmatory factor analysis. Structural equation modeling was then used to examine the associations between TUD treatment practices and clinician, setting, and patient characteristics in a sample of 182 mental health clinicians across 10 mental health clinics. RESULTS: Clinician but not setting or patient characteristics emerged as significant correlates of providing TUD treatment. Specifically, clinicians' general ethical commitment to providing TUD services and perceptions of their skills in providing this type of care were associated with providing TUD treatment. In contrast, clinician perceptions of patient motivation, anticipated quit rates, or available setting resources were not significantly associated with providing TUD treatment. CONCLUSIONS: Enhancing community mental health clinician TUD treatment skills and commitment to providing such services may reduce TUD rates among people with SMI. Future studies should evaluate interventions that target these factors.