Multiple Pharmacotherapy Adaptations for Smoking Cessation Based on Treatment Response in Black Adults Who Smoke: A Randomized Clinical Trial

Abstract

Importance: Adapting to different smoking cessation medications when an individual has not stopped smoking has shown promise, but efficacy has not been tested in racial and ethnic minority individuals who smoke and tend to have less success in quitting and bear a disproportionate share of tobacco-related morbidity and mortality.

Objective: To evaluate efficacy of multiple smoking cessation pharmacotherapy adaptations based on treatment response in Black adults who smoke daily.

Design, setting, and participants: This randomized clinical trial of adapted therapy (ADT) or enhanced usual care (UC) included non-Hispanic Black adults who smoke and was conducted from May 2019 to January 2022 at a federally qualified health center in Kansas City, Missouri. Data analysis took place from March 2022 to January 2023.

Interventions: Both groups received 18 weeks of pharmacotherapy with long-term follow-up through week 26. The ADT group consisted of 196 individuals who received a nicotine patch (NP) and up to 2 pharmacotherapy adaptations, with a first switch to varenicline at week 2 and, if needed, a second switch to bupropion plus NP (bupropion + NP) based on carbon monoxide (CO)-verified smoking status (CO ≥6 ppm) at week 6. The UC group consisted of 196 individuals who received NP throughout the duration of treatment.

Main outcomes and measures: Anabasine-verified and anatabine-verified point-prevalence abstinence at week 12 (primary end point) and weeks 18 and 26 (secondary end points). The χ2 test was used to compare verified abstinence at week 12 (primary end point) and weeks 18 and 26 (secondary end points) between ADT and UC. A post hoc sensitivity analysis of smoking abstinence at week 12 was performed with multiple imputation using a monotone logistic regression with treatment and gender as covariates to impute the missing data.

Results: Among 392 participants who were enrolled (mean [SD] age, 53 [11.6] years; 224 [57%] female; 186 [47%] ≤ 100% federal poverty level; mean [SD] 13 [12.4] cigarettes per day), 324 (83%) completed the trial. Overall, 196 individuals were randomized to each study group. Using intent-to-treat and imputing missing data as participants who smoke, verified 7-day abstinence was not significantly different by treatment group at 12 weeks (ADT: 34 of 196 [17.4%]; UC: 23 of 196 [11.7%]; odds ratio [OR], 1.58; 95% CI, 0.89-2.80; P = .12), 18 weeks (ADT: 32 of 196 [16.3%]; UC: 31 of 196 [15.8%]; OR, 1.04; 95% CI, 0.61-1.78; P = .89), and 26 weeks (ADT: 24 of 196 [12.2%]; UC: 26 of 196 [13.3%]; OR, 0.91; 95% CI, 0.50-1.65; P = .76). Of the ADT participants who received pharmacotherapy adaptations (135/188 [71.8%]), 11 of 135 (8.1%) were abstinent at week 12. Controlling for treatment, individuals who responded to treatment and had CO-verified abstinence at week 2 had 4.6 times greater odds of being abstinent at week 12 (37 of 129 [28.7%] abstinence) than those who did not respond to treatment (19 of 245 [7.8%] abstinence; OR; 4.6; 95% CI, 2.5-8.6; P < .001).

Conclusions and relevance: In this randomized clinical trial of adapted vs standard of care pharmacotherapy, adaptation to varenicline and/or bupropion + NP after failure of NP monotherapy did not significantly improve abstinence rates for Black adults who smoke relative to those who continued treatment with NP. Those who achieved abstinence in the first 2 weeks of the study were significantly more likely to achieve later abstinence, highlighting early treatment response as an important area for preemptive intervention.

Trial registration: ClinicalTrials.gov Identifier: NCT03897439.

Figure 1.. Intervention Activities by Treatment

^aMedication was dispensed at weeks 0, 2, and 6. All participants started 2 weeks of nicotine patch and received 18 total weeks of pharmacotherapy during the study. ^bSmoking status was monitored via exhaled carbon monoxide at weeks 2 and 6. Carbon monoxide of 6 ppm or higher was determined a priori to indicated continued smoking (ie, treatment nonresponse), which triggered adapation to the next pharmacotherapy. ^cCarbon monoxide monitoring resulted in 3 possible treatment pathways: path 1, nicotine patch; path 2, varenicline; and path 3, bupropion + NP.

Figure 2.. Study Flow Diagram

ADT indicates adapted therapy; UC, usual care.