Motivational, reduction and usual care interventions for smokers who are not ready to quit: a randomized controlled trial

Abstract

Aims: To test whether, in comparison to usual care, brief motivational or reduction interventions increase quit attempts (QA) or abstinence among smokers who are not ready to quit.

Design: A parallel-group randomized controlled trial of brief motivational (n = 185), reduction (n = 186) or usual care (n = 189) telephone interventions delivered over the course of 4 weeks. Outcomes were assessed at 6- and 12-month follow-ups. No medication was provided.

Setting: United States.

Participants: A total of 560 adult smokers of ≥ 10 cigarettes per day who were not ready to quit in the next 30 days.

Measurements: The primary outcomes were whether participants made a QA that lasted ≥ 24 hours and whether they made a QA of any length between baseline and 6 months. Secondary outcomes included 7-day point-prevalence abstinence at 6 and 12 months. The 12-month follow-up was added after the study began.

Findings: A priori-defined comparisons were between motivational versus usual care and reduction versus usual care conditions. The probability of making a QA that lasted ≥ 24 hours was not significantly different between the motivational (38%) or the reduction (31%) conditions and the usual care (34%) condition [motivational versus usual care odds ratio (OR) = 1.19, 95% confidence interval (CI) = 0.78-1.82; reduction versus usual care OR = 0.89, 95% CI = 0.57-1.36]. Bayes factors ranged from 0.13 to 0.18. Findings regarding a QA of any length were similar. At 6 months, the motivational condition had marginally more abstinence than usual care (11 versus 5%, OR = 2.17, 95% CI = 0.99-4.77), but the reduction condition was not significantly different from usual care (8 versus 5%, OR = 1.57, 95% CI = 0.69-3.59). At 12 months, the motivational condition had significantly more abstinence than usual care (10 versus 4%, OR = 2.80, 95% CI = 1.14-6.88) and the reduction condition had marginally more abstinence than usual care (9 versus 4%, OR = 2.45, 95% CI = 0.98-6.09).

Conclusions: Among adult smokers who are not ready to quit, both logistic regression and Bayesian analysis indicate that neither motivational nor reduction-based telephone interventions increased the odds of making a quit attempt in comparison to usual care at 6 months. The motivational intervention appeared to increase abstinence at 6 months and did increase abstinence at 12 months. The reduction intervention did not increase abstinence at 6 months but appeared to increase abstinence at 12 months.

Keywords: Brief intervention; cessation; motivational interviewing; randomized controlled trial; reduction; tobacco.