James O. Prochaska

The transtheoretical model of health behavior change

The transtheoretical model posits that health behavior change involves progress through six stages of change: precontemplation, contemplation, preparation, action, maintenance, and termination. Ten processes of change have been identified for producing progress along with decisional balance, self-efficacy, and temptations. Basic research has generated a rule of thumb for at-risk populations: 40% in precontemplation, 40% in contemplation, and 20% in preparation. Across 12 health behaviors, consistent patterns have been found between the pros and cons of changing and the stages of change. Applied research has demonstrated dramatic improvements in recruitment, retention, and progress using stage-matched interventions and proactive recruitment procedures. The most promising outcomes to date have been found with computer-based individualized and interactive interventions. The most promising enhancement to the computer-based programs are personalized counselors. One of the most striking results to date for stage-matched programs is the similarity between participants reactively recruited who reached us for help and those proactively recruited who we reached out to help. If results with stage-matched interventions continue to be replicated, health promotion programs will be able to produce unprecedented impacts on entire at-risk populations.

The Process of Smoking Cessation: An Analysis of Precontemplation, Contemplation, and Preparation Stages of Change.

Traditionally smoking cessation studies use smoker and nonsmoker categories almost exclusively to represent individuals quitting smoking. This study tested the transtheoretical model of change that posits a series of stages through which smokers move as they successfully change the smoking habit. Subjects in precontemplation (n = 166), contemplation (n = 794), and preparation (n = 506) stages of change were compared on smoking history, 10 processes of change, pretest self-efficacy, and decisional balance, as well as 1-month and 6-month cessation activity. Results strongly support the stages of change model. All groups were similar on smoking history but differed dramatically on current cessation activity. Stage differences predicted attempts to quit smoking and cessation success at 1- and 6-month follow-up. Implications for recruitment, intervention, and research are discussed.

Toward a Comprehensive Model of Change

In 1984, a group of researchers, theorists, and therapists gathered at an international conference in Scotland to contribute to the development of a more comprehensive model of change for the treatment of addictive behaviors. The conference and this book that grew out of the conference are signs of the Zeitgeist; they are part of a new attempt to integrate diverse systems of psychotherapy (Prochaska, 1984). In his classic call for a rapproachment across competing systems of therapy, Goldfried (1980) signaled that it is time to move beyond parochial approaches to treatment. It is time to move toward more comprehensive models of change.

Decisional balance measure for assessing and predicting smoking status.

The Decisional Balance Sheet of Incentives has been proposed by Janis and Mann (1977) as a general schema for representing both the cognitive and motivational aspects of human decision making. In this study, a brief 24-item paper and pencil measure was constructed to study the decision-making process in smoking cessation. Two scales were identified and labeled the Pros of Smoking and the Cons of Smoking. These scales were successful in differentiating between five groups representing stages of change in the quitting process. The two scales were also successful when employed as predictors of smoking status at a 6-month follow-up. The Decisional Balance Scale appears to be a powerful construct of potentially wide application in behavior change.

Assessing outcome in smoking cessation studies.

Outcome measures for smoking cessation are reviewed and evaluated, including 3 self-report measures and 3 biochemical validation measures. Point prevalence reflects the percentage of participants taking action, prolonged abstinence reflects those in the maintenance stage, and continuous abstinence reflects those who progress from action to maintenance without lapsing or relapsing. Biochemical assessments are primarily measures of point prevalence abstinence. The desirability of biochemical validation is a particularly controversial and critical issue. Three factors affect the accuracy of self-report: Type of Population, Type of Intervention, and Demand Characteristics. False-negative rates are generally low. Three broad issues impact on decisions to use biochemical validation: (a) alternative explanations for false positives, (b) refusal rate problems, and (c) the effect of inaccuracy on intervention assessment.

Standardized, individualized, interactive, and personalized self-help programs for smoking cessation.

Smokers (N = 756) were randomly assigned by stage of change to (a) standardized self-help manuals (ALA+ condition), (b) individualized manuals matched to stage (TTT condition), (c) interactive expert-system computer reports plus individualized manuals (ITT condition), or (d) a personalized condition with 4 counselor calls, stage manuals, and computer reports (PITT condition). Over 18 months, the ITT groups results more than doubled those of the ALA+ group on abstinence measures. The ALA+ and TTT conditions were equivalent over 12 months, but at 18 months the TTT condition was more effective. The ITT condition was the best or comparable with the best treatment at all follow-ups for smokers at all stages of change. Results suggest that an effective expert system has been developed, and discussion focuses on delivering this system to entire populations of smokers.

Relapse situations and self-efficacy: An integrative model☆☆☆

Researchers studying relapse for an addictive behavior have employed two different conceptual models. Researchers concerned with typologies of relapse situations have developed a variety of discrete classes of high risk situations. Researchers who have employed a Self-efficacy approach have typically assessed different situations but scored the measure as a single general construct. Using structural modeling, this paper evaluates five alternative measurement models, representing alternative conceptualizations. A hierarchical model which integrates the previously competing models provided the best fit to the data and serves to explain a large body of previous findings. The model includes three first order constructs (Positive/Social; Negative/Affective; and Habit/Addictive) and one general second-order factor. The results were replicated across two different response formats and two different subject samples.

Self-change and therapy change of smoking behavior: A comparison of processes of change in cessation and maintenance☆

Cigarette smokers who quit on their own (n = 29) were compared with subjects from two commercial therapy programs: Aversion Group (n = 18) and Behavior Management Group (n = 16). Subjects were administered a Change-Process Questionnaire and a demographic and smoking-history questionnaire within seven weeks of successful cessation, then interviewed again in five months. Using a transtheoretical model of change developed by Prochaska (1979) six verbal and four behavioral processes of change and three stages of change (Decision to Change; Active Change; Maintenance) were analyzed. Subjects in each treatment group were middle class, heavy-smoking adults. The change-process analysis of cessation discriminated between the self-quitters and therapy quitters and between the two groups of therapy subjects on five variables. Stages of change interacted with the processes of change in the cessation of smoking behavior. Verbal processes were seen as important in making the decision to change while action processes were critical for breaking the actual smoking habit. Maintenance of cessation was related to, but not dependent on, how subjects actively changed smoking behavior.

Self-efficacy and the stages of self-change of smoking

Efficacy expectations are postulated to mediate all behavior change. This study examined the construct of self-efficacy in the self-change of smoking behavior. A 31-item measure of self-efficacy was used that included ratings of both temptation (cue strength) and confidence (efficacy). The subjects were 957 volunteers representing five stages of self change: (1) immotives, (2) contemplators, (3) recent quitters, (4) long-term quitters, and (5) relapsers. Subjects were assessed initially and at a 3- to 5-month follow-up. The self-efficacy scale proved to be an extremely reliable and coherent instrument with identifiable but not clearly interpretable subcomponents. Groups of subjects demonstrated significant differences in total self-efficacy scores. Efficacy expectations demonstrated small but significant relationships with smoking history variables and the pros and cons of smoking, but not with demographic, life stress, or persistence measures. Subjects efficacy evaluations at the initial assessment were related to changes in status for recent quitters and contemplators at the follow-up. The relationship between temptation and efficacy ratings is complex and varies for subjects in the various stages of change. Correlations between total self-efficacy and temptation scores were largest for contemplators (r = −.65) and relapsers (r = −.67) and smallest for the recent quitters (r = −.18). Finally, the magnitude of the difference between temptation and efficacy increased with length of abstinence for subjects in maintenance.

Strong and weak principles for progressing from precontemplation to action on the basis of twelve problem behaviors.

Two principles for progressing from the precontemplation stage of change to the action stage were discovered. The strong principle states that progression from precontemplation to action is a function of approximately a 1 standard deviation increase in the pros of a health behavior change. The weak principle states that progression from precontemplation to action is a function of approximately a 1/2 standard deviation decrease in the cons of a health behavior change. In Study 1, these principles were derived from cross-sectional data on 12 problem behaviors relating the pros and cons of changing to the stages of change. In Study 2, these principles were validated on cross-sectional data from an independent sample of 1,466 smokers. Discussion focuses on the implications of these principles for individual psychology and public health policy.