Early Treatment Response in Black Smokers Undergoing Pharmacotherapy for Smoking Cessation

This secondary analysis of a randomized clinical trial investigates the association of early treatment response with smoking cessation among Black smokers.


Introduction
When smokers achieve abstinence in the first few weeks of treatment (ie, early treatment response), they have significantly greater odds of remaining abstinent at later times. 1 Understanding factors that increase odds of early response may help identify which individuals are likely to have early success and could guide clinical decision-making.This analysis examined early treatment response (abstinence at 2 weeks) and its effect on long-term abstinence (at 26 weeks) and identified baseline factors that increased odds of early response.

Methods
The parent study to this secondary analysis (not prespecified) was an open-label randomized clinical trial among smokers who self-identified as non-Hispanic Black and were interested in quitting smoking. 2,3After written informed consent, participants were randomized to standard (7 sessions of counseling with nicotine patch) or adaptive (including Ն2 pharmacotherapy adaptations [varenicline and bupropion with patch]) treatment.Groups received identical treatment with a 21-mg nicotine patch for the first 2 weeks.Adaptations occurred at weeks 2 and 6 based on biochemically confirmed smoking status, with carbon monoxide (CO) levels of 5 ppm or less indicating treatment response.
Participants received 18 weeks of pharmacotherapy with long-term follow-up at week 26 (biochemically confirmed abstinence with anatabine and anabasine Յ2 ng/mL).The study was approved by the University of Kansas Medical Center's Institutional Review Board and followed the CONSORT reporting guideline (see trial protocol in Supplement 1 and study flowchart in the eFigure in Supplement 2).This study did not require additional review, approval, or consent given that data were deidentified.
Table 1 presents baseline biopsychosocial variables selected for this analysis based on studies of factors that increased odds of cessation.The effect of early treatment response (week 2) on longterm abstinence (week 26) was assessed using logistic regression with treatment included as a factor in the model; multiple logistic regression using best subset variable selection was used to investigate factors that increased odds of early treatment response.For the best subset analysis, 2 modeling strategies were used.The first forced treatment into the model; the second allowed but did not force treatment into the model.Results were unchanged.The second modeling strategy was selected because all participants were on identical treatment through week 2. Analyses were conducted for week 2 and 26 completers only using SAS statistical software version 9.4 (SAS Institute).All tests were 2-sided, and statistical significance was set at .05.

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a Biochemically confirmed by carbon monoxide (CO) levels of 5 ppm or less at week 2.
b T tests were performed for continuous measures, and χ 2 tests were performed for categorical or dichotomous measures.
c Participants self-reported number of CPD during the past 7 days.
e Minnesota Tobacco Withdrawal Scale (range, 0-32; higher scores indicate greater symptoms of withdrawal).
f A 10-item scale described problems that could arise in any area.Participants rated the extent of each problem using a 3-point scale from 1 (not a problem) to 2 (some problem) to 3 (serious problem).Answers were summed for the total score (range, 10-30).
h Participants self-reported marijuana use in the past 7 days (yes or no).
i Self-reported past 7-day use of other tobacco products, including cigars, cigarillos, pipes, smokeless tobacco, hookah, or bidis (yes or no).
k Frequency of perceived discrimination in day-to-day experience, with response options ranging from 0 ("never") to 5 ("almost every day"); overall range was 0 to 25.

JAMA Network Open | Substance Use and Addiction
Early Treatment Response Among Black Smokers Undergoing Pharmacotherapy