Tobacco use is the primary cause of preventable diseases in the United States. In 2009, an estimated 46.6 million adults in the United States were current smokers [1
]. Smoking in the US accounts for about 443,000 deaths yearly, approximately 5.1 million in years of potential life lost, and $96.8 billion in productivity losses [2
]. Reducing the prevalence of smoking remains one of the country’s most important public health goals [1
To reduce the health and social consequences of tobacco use, it is essential to reduce the decades-long lag between initiation of regular smoking and cessation. Many smokers will smoke for 20–30
years before quitting [3
]. The sooner a smoker stops, the greater the gains in life expectancy [4
]. Although most smokers are “interested” in quitting smoking [5
], approximately 40% are not planning on quitting in the next 6-months and another 40% have no plans to quit in the next month [6
]. Unfortunately, established clinical smoking cessation interventions focus on those in the remaining 20% that are ready and seeking assistance to quit. For example, many tobacco quit-lines in the United States, require callers to be ready to quit before comprehensive services are provided [7
]. Likewise, primary care physicians are less likely to counsel patients to quit, or refer them to counseling, if they believe the patient is not ready to quit [8
]. Given those not ready to quit comprise a large majority of the smoking population, proactive intervention with less motivated smokers could have a significant public health impact, even if such intervention had only moderate efficacy [10
One promising approach to encourage cessation among less motivated smokers is Motivational Interviewing (MI), a treatment approach that emerged from the alcohol and drug treatment literature that focuses on fostering motivation for, and commitment to behavior change. MI has been defined as a collaborative, person-centered form of guiding to elicit and strengthen motivation for change [11
]. Principles of MI include using a collaborative style, eliciting individuals’ reasons for change rather than persuading, and supporting autonomy so that individuals do not feel pressured to change and can feel autonomously or “internally” motivated. These principles are manifested in communication methods (e.g., open-ended questions, affirming, and reflective listening) that are used to strategically elicit and enhance the individual’s elaboration of “change talk” (statements in the direction of making a change) and increase their awareness of the discrepancy between their current behavior and their perception of what would be ideal behavior. These strategies are thought to be more effective than questioning, persuading, or giving advice.
Meta-analyses have indicated that MI-based interventions have modest positive effects on smoking cessation relative to interventions such as brief advice to quit [12
]. However, the Clinical Practice Guideline and several meta-analyses have noted significant deficiencies in the evidence base [12
]. Significant limitations of the existing literature include the inadequate evidence of intervention fidelity, the lack of research comparing MI to alternative interventions of equal intensity, and the lack of focus on the role of motivation to quit and motivation and quit attempts as outcomes [12
]. Evidence of fidelity to MI principles is essential for internal validity and because null effects could be due to “Type 3 error” (i.e., low quality implementation rather than ineffective treatment), yet prior MI studies have rarely included the use of a validated instrument for assessing MI adherence [12
Equally important for advancing the research on MI is whether the positive effects observed in prior studies can be attributed to the benefits of MI or simply to the greater duration of contact with participants. Teasing out counseling approach effects from general attention effects is critical given the cost and complexity of implementing an MI intervention. For example, studies have shown that significant training and practice is necessary for MI to be properly implemented [16
] and there is a lack of research comparing MI with potentially more straightforward but equally intensive interventions (e.g. intensive health education) [12
A third major concern with the existing evidence base for MI is the lack of attention to the role of motivation. Motivation mediates cessation outcomes and, according to meta-analysis, MI may be more effective for low motivated smokers [17
]. Accordingly, there is also evidence that cognitive-behavioral skills training may be more effective than MI for smokers already motivated to make a quit attempt [18
]. Taken together, these findings suggest that tailoring counseling style to motivational level may be most effective.
The purpose of the present study is to conduct a randomized controlled trial to examine the efficacy of MI for inducing quit attempts among low motivated smokers while addressing key limitations of prior studies. The primary outcome will be the effect of MI on any quit attempt by the 6-month follow-up relative to an intensity-matched control condition (Health Education; HE) and minimal intervention control condition (Brief Advice to quit; BA). The secondary outcome is biochemically confirmed 7-day point-prevalence cessation rates at 6-month follow-up. Participants’ perceived autonomy support from their counselor and autonomous motivation for quitting will be examined as mediators of any treatment effect on quit attempts. Participants who choose to set a quit date for a quit attempt will be offered pharmacotherapy and pharmacotherapy use will also be examined as a mediator of MI’s effect on cessation. In addition, the goal is to implement the MI intervention with high fidelity verified with independent coders using a validated coding scheme. The study uses quit attempts rather than cessation as the primary outcome to reduce the needed sample size. The study aims to be a preliminary step toward a much larger trial that will also include more highly motivated participants for comparison and focus on smoking cessation as the main outcome.