Enhanced motivational interviewing versus brief advice for adolescent smoking cessation: Results from a randomized clinical trial

Abstract

Background

Motivational interviewing (MI) is widely used for adolescent smoking cessation but empirical support for this approach is mixed.

Methods

Adolescent cigarette smokers 14–18 years old (N = 162) were recruited from medical, school, and community settings and randomly assigned to enhanced MI or brief advice (BA) for smoking cessation. MI comprised an in-person individual session, a telephone booster session one week later, and a brief telephone-based parent intervention. BA consisted of standardized brief advice to quit smoking. Assessments occurred at baseline, post-treatment and at 1-, 3-, and 6-month follow ups.

Results

Biochemically-confirmed 7-day point prevalence abstinence rates were low (e.g., 4.5% for MI; 1.4% for BA at 1 month) and did not differ significantly by group at any follow up. Only those in MI reported significant decreases in cigarettes smoked per day (CPD) from baseline to 1 month. At 3 and 6 months, smokers in both groups reported significantly reduced CPD with no differences between groups. MI reduced perceived norms regarding peer and adult smoking rates, while BA had no effect on normative perceptions. No group differences emerged for self-reported motivation or self-efficacy to quit smoking.

Conclusions

Findings support the efficacy of MI for addressing normative misperceptions regarding peer and adult smoking and for modestly reducing CPD in the short-term; however, these effects did not translate to greater smoking abstinence. MI may have more promise as a prelude to more intensive smoking intervention with adolescents than as a stand-alone intervention.

Introduction

Tobacco use is the leading preventable cause of death globally (Beaglehole et al., 2011). Each day, between 82,000 and 99,000 youth worldwide begin smoking (Mackay, Eriksen, & Shafey, 2006), and in the US this results in approximately 1.5 million new smokers under the age of 18 every year (Substance Abuse and Mental Health Services Administration, 2009). According to the Monitoring the Future national surveillance study, 7% of eighth graders, 13% of tenth graders and 20% of twelfth graders report current smoking (Johnston, O'Malley, Bachman, & Schulenberg, 2010). Smoking during adolescence is particularly concerning because early smoking onset is associated with higher adult smoking rates and lower odds of successfully quitting smoking (Breslau and Peterson, 1996, Coambs et al., 1992). Following declines in adolescent smoking in the US, smoking prevalence among adolescents has stalled at these unacceptably high rates.

The adolescent smoking cessation literature based on randomized clinical trials provides some support for motivational, cognitive-behavioral, and/or social influence approaches for adolescent smoking cessation (Gervais et al., 2007, Grimshaw and Stanton, 2006, Heckman et al., 2010, Hettema and Hendricks, 2010, Sussman and Sun, 2009) with limited evidence to support the use of pharmacological interventions for adolescent smoking cessation (Colby and Gwaltney, 2007, Curry et al., 2009).

Motivational enhancement interventions are among the most widely used approaches for adolescent smoking cessation (Curry et al., 2009). Motivational interviewing (MI) is a brief, client-centered approach focused on resolving ambivalence regarding quitting and increasing self-efficacy for change. MI uses a nonjudgmental, directive, and supportive therapeutic style that emphasizes personal responsibility for making decisions about change (Miller & Rollnick, 2002) and often incorporates personalized feedback, designed to correct normative misperceptions and heighten awareness of personally-relevant consequences of smoking. An individual change plan can be developed collaboratively from a menu of options (Colby et al., 1998, Colby et al., 2005).

Although several studies have failed to demonstrate significant effects of MI for promoting confirmed abstinence in adolescents (Brown et al., 2003, Colby et al., 2005, Horn et al., 2007), two recent multi-study analyses found significantly greater abstinence among adolescent smokers following MI versus a comparison intervention (Heckman et al., 2010, Hettema and Hendricks, 2010). In one study, pooled data from eight adolescent trials indicated that MI roughly doubled the odds of smoking abstinence at follow up, from 6% in comparison conditions to 11.5% in MI (Heckman et al., 2010). In a meta-analysis of 23 studies (including 6 adolescent trials), the overall effect of MI versus comparison intervention was significant at long-term follow ups (≥ 6 months) but not shorter-term follow ups. Subgroup analysis of the adolescent studies found significant combined effects at short- and long-term follow ups (Hettema & Hendricks, 2010). All effect sizes fell below Cohen's criterion for a small effect (Cohen, 1988), thus the large samples required to detect treatment effects may explain the discrepancy between non-significant findings in individual trials versus significant effects in pooled analyses and meta-analyses.

In the current trial, we attempted to bolster the effect size of MI by adding two new components, a one-week telephone booster session and a brief parent intervention, also administered via telephone. The basis for incorporating parent intervention was the widely documented influence of parent smoking behaviors and attitudes on adolescent smoking (Chassin et al., 2008, den Exter Blokland et al., 2004, Flay et al., 1998, Gilman et al., 2009, Thomas et al., 2009, Tyas and Pederson, 1998, White et al., 2002, Withers et al., 2000). Adolescents whose parents smoke are more likely to smoke themselves, and the odds of smoking initiation and progression are greater for those who have two parents who smoke relative to having one parent who smokes (Gilman et al., 2009, Peterson et al., 2006). In contrast, parental disapproval of smoking, stronger anti-smoking beliefs, and household smoking restrictions decrease the odds of adolescent smoking (Andersen et al., 2004, Huver et al., 2006, Kodl and Mermelstein, 2004) and adolescent experimental smokers who perceive strong parental disapproval are less likely to progress to regular smoking, even if their parents are smokers (Sargent & Dalton, 2001).

This study compared enhanced MI to brief advice (BA) for adolescent smoking cessation at 1, 3, and 6 months follow up. We hypothesized that MI would result in significantly greater smoking abstinence and smoking reductions compared with BA. A secondary aim was to examine the proximal effects of MI on motivation to change, quitting self-efficacy, and normative perceptions about smoking.