||This article has been nominated to be checked for its neutrality. (December 2011)|
||This article contains a pro and con list, which is sometimes inappropriate. (May 2013)|
The transtheoretical model of behavior change assesses an individual's readiness to act on a new healthier behavior, and provides strategies, or processes of change to guide the individual through the stages of change to Action and Maintenance.
The transtheoretical model is also known by the abbreviation "TTM" and by the term "stages of change." A popular book, Changing for Good, and articles in the news media have discussed the model. It is "arguably the dominant model of health behaviour change, having received unprecedented research attention, yet it has simultaneously attracted criticism."
- 1 History and core constructs of the model
- 2 Outcomes of TTM programs
- 3 TTM criticisms
- 4 See also
- 5 Notes
- 6 References
- 7 Further reading
- 8 External links
History and core constructs of the model
James O. Prochaska of the University of Rhode Island and colleagues developed the transtheoretical model beginning in 1977. It is based on analysis and use of different theories of psychotherapy, hence the name "transtheoretical."
Prochaska and colleagues refined the model on the basis of research that they published in peer-reviewed journals and books. The model consists of four "core constructs": "stages of change," "processes of change," "decisional balance," and "self-efficacy."
TTM research breakthroughs
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- 1980s 
- Invention of the Stages of Change and the dynamic change processes and principles related to each stage
- Developed first computer-tailored intervention based on the transtheoretical model (TTM)
- Demonstrated tailored interventions for smoking cessation effective even when more than 80% were not ready to quit
- TTM applied to a variety of behaviors beyond smoking cessation
- Demonstrated that TTM-based interventions for simultaneous multiple behavior change are effective
- TTM applied to a wide variety of new behavior change challenges
- Implemented innovative strategies to ensure greater impact on multiple behaviors with fewer demands on patients and providers
- Designed a more cost-effective delivery for coaching and online programs
- Serving entire populations with inclusive proactive and home-based care
- Expanding focus from health promotion to well-being
Stages of change
- Precontemplation (Not Ready)-"People are not intending to take action in the foreseeable future, and can be unaware that their behaviour is problematic"
- Contemplation (Getting Ready)-"People are beginning to recognize that their behaviour is problematic, and start to look at the pros and cons of their continued actions"
- Preparation (Ready)-"People are intending to take action in the immediate future, and may begin taking small steps toward behaviour change"[nb 1]
- Action – "People have made specific overt modifications in modifying their problem behaviour or in acquiring new healthy behaviours"
- Maintenance – "People have been able to sustain action for at least six months and are working to prevent relapse"
- Termination – "Individuals have zero temptation and they are sure they will not return to their old unhealthy habit as a way of coping"[nb 2]
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Stage 1: Precontemplation (Not Ready)
People at this stage do not intend to start the healthy behavior in the near future (within 6 months), and may be unaware of the need to change. People here learn more about healthy behavior: they are encouraged to think about the pros of changing their behavior and to feel emotions about the effects of their negative behavior on others.
Precontemplators typically underestimate the pros of changing, overestimate the cons, and often are not aware of making such mistakes.
One of the most effective steps that others can help with at this stage is to encourage them to become more mindful of their decision making and more conscious of the multiple benefits of changing an unhealthy behavior.
Stage 2: Contemplation (Getting Ready)
At this stage, participants are intending to start the healthy behavior within the next 6 months. While they are usually now more aware of the pros of changing, their cons are about equal to their Pros. This ambivalence about changing can cause them to keep putting off taking action.
People here learn about the kind of person they could be if they changed their behavior and learn more from people who behave in healthy ways.
Others can influence and help effectively at this stage by encouraging them to work at reducing the cons of changing their behavior.
Stage 3: Preparation (Ready)
People at this stage are ready to start taking action within the next 30 days. They take small steps that they believe can help them make the healthy behavior a part of their lives. For example, they tell their friends and family that they want to change their behavior.
People in this stage should be encouraged to seek support from friends they trust, tell people about their plan to change the way they act, and think about how they would feel if they behaved in a healthier way. Their number one concern is: when they act, will they fail? They learn that the better prepared they are, the more likely they are to keep progressing.
Stage 4: Action
People at this stage have changed their behavior within the last 6 months and need to work hard to keep moving ahead. These participants need to learn how to strengthen their commitments to change and to fight urges to slip back.
People in this stage progress by being taught techniques for keeping up their commitments such as substituting activities related to the unhealthy behavior with positive ones, rewarding themselves for taking steps toward changing, and avoiding people and situations that tempt them to behave in unhealthy ways.
Stage 5: Maintenance
People at this stage changed their behavior more than 6 months ago. It is important for people in this stage to be aware of situations that may tempt them to slip back into doing the unhealthy behavior—particularly stressful situations.
It is recommended that people in this stage seek support from and talk with people whom they trust, spend time with people who behave in healthy ways, and remember to engage in healthy activities to cope with stress instead of relying on unhealthy behavior.
Processes of change
The 10 processes of change are "covert and overt activities that people use to progress through the stages."
To progress through the early stages, people apply cognitive, affective, and evaluative processes. As people move toward Action and Maintenance, they rely more on commitments, conditioning, contingencies, environmental controls, and support.
Prochaska and colleagues state that their research related to the transtheoretical model shows that interventions to change behavior are more effective if they are "stage-matched," that is, "matched to each individual's stage of change."[nb 4]
In general, for people to progress they need:
- A growing awareness that the advantages (the "pros") of changing outweigh the disadvantages (the "cons")—the TTM calls this decisional balance
- Confidence that they can make and maintain changes in situations that tempt them to return to their old, unhealthy behavior—the TTM calls this self-efficacy
- Strategies that can help them make and maintain change—the TTM calls these processes of change. The ten processes include:
- Consciousness-Raising—increasing awareness via information, education, and personal feedback about the healthy behavior.
- Dramatic Relief—feeling fear, anxiety, or worry because of the unhealthy behavior, or feeling inspiration and hope when they hear about how people are able to change to healthy behaviors
- Self-Reevaluation—realizing that the healthy behavior is an important part of who they are and want to be
- Environmental Reevaluation—realizing how their unhealthy behavior affects others and how they could have more positive effects by changing
- Social Liberation—realizing that society is more supportive of the healthy behavior
- Self-Liberation—believing in one’s ability to change and making commitments and recommitments to act on that belief
- Helping Relationships—finding people who are supportive of their change
- Counter-Conditioning—substituting unhealthy ways of acting and thinking for healthy ways
- Reinforcement Management—increasing the rewards that come from positive behavior and reducing those that come from negative behavior
- Stimulus Control—using reminders and cues that encourage healthy behavior as substitutes for those that encourage the unhealthy behavior.
This core construct "reflects the individual's relative weighing of the pros and cons of changing."[nb 5] Decision making was conceptualized by Janis and Mann as a "decisional balance sheet" of comparative potential gains and losses." Decisional balance measures, the pros and the cons, have become critical constructs in the transtheoretical model. The pros and cons combine to form a decisional "balance sheet" of comparative potential gains and losses. The balance between the pros and cons varies depending on which stage of change the individual is in.
Sound decision making requires the consideration of the potential benefits (pros) and costs (cons) associated with a behavior's consequences. TTM research has found the following relationships between the pros, cons, and the stage of change across 48 behaviors and over 100 populations studied.
- The cons of changing outweigh the pros in the Precontemplation stage.
- The pros surpass the cons in the middle stages.
- The pros outweigh the cons in the Action stage.
This core construct is "the situation-specific confidence people have that they can cope with high-risk situations without relapsing to their unhealthy or high risk-habit."[nb 6] Self-efficacy conceptualizes a person's perceived ability to perform on a task as a mediator of performance on future tasks. A change in the level of self-efficacy can predict a lasting change in behavior if there are adequate incentives and skills. The transtheoretical model employs an overall confidence score to assess an individual's self-efficacy. Situational temptations assess how tempted people are to engage in a problem behavior in a certain situation.
Outcomes of TTM programs
The outcomes of the TTM computerized tailored interventions administered to participants in pre-Action stages are outlined below.
A national sample of pre-Action adults was provided a stress management intervention. At the 18-month follow-up, a significantly larger proportion of the treatment group (62%) was effectively managing their stress when compared to the control group. The intervention also produced statistically significant reductions in stress and depression and an increase in the use of stress management techniques when compared to the control group. Two additional clinical trials of TTM programs by Prochaska et al. and Jordan et al. also found significantly larger proportions of treatment groups effectively managing stress when compared to control groups.
Adherence to antihypertensive medication
Over 1,000 members of a New England group practice who were prescribed antihypertensive medication participated in an adherence to antihypertensive medication intervention. The vast majority (73%) of the intervention group who were previously pre-Action were adhering to their prescribed medication regimen at the 12-month follow-up when compared to the control group.
Adherence to lipid-lowering drugs
Members of a large New England health plan and various employer groups who were prescribed a cholesterol lowering medication participated in an adherence to lipid-lowering drugs intervention. More than half of the intervention group (56%) who were previously pre-Action were adhering to their prescribed medication regimen at the 18-month follow-up. Additionally, only 15% of those in the intervention group who were already in Action or Maintenance relapsed into poor medication adherence compared to 45% of the controls. Further, participants who were at risk for physical activity and unhealthy diet were given only stage-based guidance. The treatment group doubled the control group in the percentage in Action or Maintenance at 18 months for physical activity (43%) and diet (25%).
Participants were 350 primary care patients experiencing at least mild depression but not involved in treatment or planning to seek treatment for depression in the next 30 days. Patients receiving the TTM intervention experienced significantly greater symptom reduction during the 9-month follow-up period. The intervention’s largest effects were observed among patients with moderate or severe depression, and who were in the Precontemplation or Contemplation stage of change at baseline. For example, among patients in the Precontemplation or Contemplation stage, rates of reliable and clinically significant improvement in depression were 40% for treatment and 9% for control. Among patients with mild depression, or who were in the Action or Maintenance stage at baseline, the intervention helped prevent disease progression to Major Depression during the follow-up period.
Twelve-hundred-and-seventy-seven overweight or moderately obese adults (BMI 25-39.9) were recruited nationally, primarily from large employers. Those randomly assigned to the treatment group received a stage-matched multiple behavior change guide and a series of tailored, individualized interventions for three health behaviors that are crucial to effective weight management: healthy eating (i.e., reducing calorie and dietary fat intake), moderate exercise, and managing emotional distress without eating. Up to three tailored reports (one per behavior) were delivered based on assessments conducted at four time points: baseline, 3, 6, and 9 months. All participants were followed up at 6, 12, and 24 months. Multiple Imputation was used to estimate missing data. Generalized Estimating Equations (GEE) were then used to examine differences between the treatment and comparison groups. At 24 months, those who were in a pre-Action stage for healthy eating at baseline and received treatment were significantly more likely to have reached Action or Maintenance than the comparison group (47.5% vs. 34.3%). The intervention also impacted a related, but untreated behavior: fruit and vegetable consumption. Over 48% of those in the treatment group in a pre-Action stage at baseline progressed to Action or Maintenance for eating at least 5 servings a day of fruit and vegetables as opposed to 39% of the comparison group. Individuals in the treatment group who were in a pre-Action stage for exercise at baseline were also significantly more likely to reach Action or Maintenance (44.9% vs. 38.1%). The treatment also had a significant effect on managing emotional distress without eating, with 49.7% of those in a pre-Action stage at baseline moving to Action or Maintenance versus 30.3% of the comparison group. The groups differed on weight lost at 24 months among those in a pre-action stage for healthy eating and exercise at baseline. Among those in a pre-Action stage for both healthy eating and exercise at baseline, 30% of those randomized to the treatment group lost 5% or more of their body weight vs.18.6% in the comparison group. Coaction of behavior change occurred and was much more pronounced in the treatment group with the treatment group losing significantly more than the comparison group. This study demonstrates the ability of TTM-based tailored feedback to improve healthy eating, exercise, managing emotional distress, and weight on a population basis. The treatment produced the highest population impact to date on multiple health risk behaviors.
Multiple studies have found individualized interventions tailored on the 14 TTM variables for smoking cessation to effectively recruit and retain pre-Action participants and produce long-term abstinence rates within the range of 22% – 26%. These interventions have also consistently outperformed alternative interventions including best-in-class action-oriented self-help programs, non-interactive manual-based programs, and other common interventions. Furthermore, these interventions continued to move pre-Action participants to abstinence even after the program ended. For a summary of smoking cessation clinical outcomes, see Velicer, Redding, Sun, & Prochaska, 2007 and Jordan, Evers, Spira, King & Lid, 2013.
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Among the criticisms of the model are the following:
- Little experimental evidence exists to suggest that application of the model is actually associated with changes in health-related behaviors.
- In a systematic review, published in 2003, of 23 randomized controlled trials, the authors determined that "stage based interventions are no more effective than non-stage based interventions or no intervention in changing smoking behaviour."
- A second systematic review from 2003 asserted that "no strong conclusions" can be drawn about the effectiveness of interventions based on the transtheoretical model for the prevention of pregnancy and sexually transmitted diseases.
- A 2005 systematic review of 37 randomized controlled trials claimed that "there was limited evidence for the effectiveness of stage-based interventions as a basis for behavior change." Additional research suggests that the effectiveness of interventions can be increased if they are tailored on all core constructs of the TTM in addition to stage of change.
- According to a randomized controlled trial published in 2006, a stage-matched intervention for smoking cessation in pregnancy was more effective than a non-stage-matched intervention, but this finding could have resulted from the "greater intensity" of the stage-matched intervention.
- A randomized controlled trial published in 2009 found "no evidence" that a smoking cessation intervention based on the transtheoretical model was more effective than a control intervention that was not tailored for stage of change.
- A 2009 review stated that "existing data are insufficient for drawing conclusions on the benefits of the transtheoretical model" as related to dietary interventions for people with diabetes.
- A 2010 systematic review of smoking cessation studies under the auspices of the Cochrane Collaboration found that "stage-based self-help interventions (expert systems and/or tailored materials) and individual counselling were neither more nor less effective than their non-stage-based equivalents."
- A 2011 Cochrane Systematic Review found that there is little evidence to suggest that using the Transtheoretical Model Stages of Change (TTM SOC) method is effective in helping obese and overweight people lose weight.
- "Arbitrary dividing lines" are drawn between the stages. A continuous version of the model (Noel, 1999) has been proposed, where each process is first increasingly used, and then decreases in importance, as smokers make progress along some latent dimension. In this alternative view, the very notion of stage is no more necessary 
- The model makes predictions that are "incorrect or worse than competing theories."
- The model "assumes that individuals typically make coherent and stable plans," when in fact they do not.
- The algorithms and questionnaires that researchers have used to assign people to stages of change have not been standardized, compared empirically, or validated.
- The designs of many studies supporting the model have been cross-sectional, but longitudinal study data would allow for stronger causal inferences.
- In a 2002 review, the model's stages were characterized as "not mutually exclusive"; furthermore, there was "scant evidence of sequential movement through discrete stages." While research suggests that movement through the stages of change is not always linear, a study conducted in 1996 demonstrated that the probability of forward stage movement is greater than the probability of backward stage movement.
- In the 1983 version of the model, the Preparation stage is absent.
- In the 1983 version of the model, the Termination stage is absent. In the 1992 version of the model, Prochaska et al. showed Termination as the end of their "Spiral Model of the Stages of Change," not as a separate stage.
- In the 1983 version of the model, Relapse is considered one of the five stages of change.
- In the 1983 version of the model, the processes of change were said to be emphasized in only the Contemplation, Action, and Maintenance stages.
- In the 1983 version of the model, "decisional balance" is absent. In the 1992 version of the model, Prochaska et al. mention "decisional balance" but in only one sentence under the "key transtheoretical concept" of "processes of change."
- In the 1983 version of the model, "self-efficacy" is absent. In the 1992 version of the model, Prochaska et al. mention "self-efficacy" but in only one sentence under the "key transtheoretical concept" of "stages of change."
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