Transtheoretical model

thumb|upright=1.5|Stages of change, according to the transtheoretical model.

The transtheoretical model of behavior change is an integrative theory of therapy that assesses an individual's readiness to act on a new healthier behavior, and provides strategies, or processes of change to guide the individual. The model is composed of constructs such as: stages of change, processes of change, levels of change, self-efficacy, and decisional balance. and sometimes by the term "stages of change", although this latter term is a synecdoche since the stages of change are only one part of the model along with processes of change, levels of change, etc. Several self-help books—Changing for Good (1994), Changeology (2012), and Changing to Thrive (2016)—and articles in the news media have discussed the model. In 2009, an article in the British Journal of Health Psychology called it "arguably the dominant model of health behaviour change, having received unprecedented research attention, yet it has simultaneously attracted exceptional criticism".

History and core constructs

James O. Prochaska of the University of Rhode Island, and Carlo Di Clemente and colleagues developed the transtheoretical model beginning in 1977.

Stages of change

This construct refers to the temporal dimension of behavioural change. In the transtheoretical model, change is a "process involving progress through a series of stages":

• 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"

In addition, the researchers conceptualized "Relapse" (recycling) which is not a stage in itself but rather the "return from Action or Maintenance to an earlier stage".

The quantitative definition of the stages of change (see below) is perhaps the most well-known feature of the model. However it is also one of the most critiqued, even in the field of smoking cessation, where it was originally formulated. It has been said that such quantitative definition (i.e. a person is in preparation if he intends to change within a month) does not reflect the nature of behaviour change, that it does not have better predictive power than simpler questions (i.e. "do you have plans to change..."), and that it has problems regarding its classification reliability.

Communication theorist and sociologist Everett Rogers suggested that the stages of change are analogues of the stages of the innovation adoption process in Rogers' theory of diffusion of innovations.

Details of each stage

thumb|upright=1.5|Stages of change in the transtheoretical model

{| class="wikitable"

! Stage

|Precontemplation

|Contemplation

|Preparation

|Action

|Maintenance

|Relapse

|-

! Standard time

| more than 6 months

| in the next 6 months

| in the next month

| now

| at least 6 months

| any time

|}

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 (current 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 (monitoring)

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 (such as exercise and deep relaxation) to cope with stress instead of relying on unhealthy behavior.

Relapse (recycling)

Relapse in the TTM specifically applies to individuals who successfully quit smoking or using drugs or alcohol, only to resume these unhealthy behaviors. Individuals who attempt to quit highly addictive behaviors such as drug, alcohol, and tobacco use are at particularly high risk of a relapse. Achieving a long-term behavior change often requires ongoing support from family members, a health coach, a physician, or another motivational source. Supportive literature and other resources can also be helpful to avoid a relapse from happening.

Processes of change

thumb|upright=1.5|Processes of change

The 10 processes of change are "covert and overt activities that people use to progress through the stages".

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".

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 of change include: Bartholomew et al. (2001) summarised the processes that they identified in a number of studies; Some processes are recommended in a specific stage, while others can be used in one or more stages. 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.

The evaluation of pros and cons is part of the formation of decisional balance. During the change process, individuals gradually increase the pros and decrease the cons forming a more positive balance towards the target behaviour. Attitudes are one of the core constructs explaining behaviour and behaviour change in various research domains. Other behaviour models, such as the theory of planned behavior (TPB) and the stage model of self-regulated change, also emphasise attitude as an important determinant of behaviour. The progression through the different stages of change is reflected in a gradual change in attitude before the individual acts.

Due to the use of decisional balance and attitude, travel behaviour researchers have begun to combine the TTM with the TPB. Forward uses the TPB variables to better differentiate the different stages. Especially all TPB variables (attitude, perceived behaviour control, descriptive and subjective norm) are positively show a gradually increasing relationship to stage of change for bike commuting. As expected, intention or willingness to perform the behaviour increases by stage.

Self-efficacy

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". The construct is based on Bandura's self-efficacy theory and conceptualizes a person's perceived ability to perform on a task as a mediator of performance on future tasks. In his research Bandura already established that greater levels of perceived self-efficacy leads to greater changes in behavior. This underlines the integrative nature of the transtheoretical model which combines various behavior theories. 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. Nevertheless, in 2005 the creators of the TTM stated that it is important "that both therapists and clients agree as to which level they attribute the problem and at which level or levels they are willing to target as they work to change the problem behavior". 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%).

Depression prevention

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.

Weight management

Five-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 Labor Estimating Equations (GLEE) 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. 16.6% 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.

The effectiveness of the use of this model in weight management interventions (including dietary or physical activity interventions, or both, and also combined with other interventions) for overweight and obese adults was assessed in a 2014 systematic review.

Smoking cessation

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.

Example for TTM application on smoke control

In the treatment of smoke control, TTM focuses on each stage to monitor and to achieve a progression to the next stage.

{| class="wikitable"

! Stage

! Precontemplation

! Contemplation

! Preparation

! Action

! Maintenance

! Can Relapse to an<br />earlier stage

|-

! scope="row" | Standard time

|more than 6 months

|in the next 6 months

|in the next month

|now

|at least 6 months

|any time

|-

! scope="row" | Action and intervention

|not ready to quit or demoralized

|ambivalent

|intend to quit

|take action and quit

|sustained

|back to smoke

|-

! scope="row" | Related source

| Book, newspaper, friend

| Book, newspaper, friend

| doctor, nurse, friend...

| doctor, nurse, friend...

| friend, family

| temptation, stress, distress

|}

In each stage, a patient may have multiple sources that could influence their behavior. These may include friends, books, and/or interactions with their healthcare providers. These factors could potentially influence how successful a patient may be in moving through the different stages. This stresses the importance to have continuous monitoring and efforts to maintain progress at each stage. TTM helps guide the treatment process at each stage, and may assist the healthcare provider in making an optimal therapeutic decision.

Travel research

The use of TTM in travel behaviour interventions is rather novel. A number of cross-sectional studies investigated the individual constructs of TTM, e.g. stage of change, decisional balance and self-efficacy, with regards to transport mode choice. The cross-sectional studies identified both motivators and barriers at the different stages regarding biking, walking and public transport. The motivators identified were e.g. liking to bike/walk, avoiding congestion and improved fitness. Perceived barriers were e.g. personal fitness, time and the weather. This knowledge was used to design interventions that would address attitudes and misconceptions to encourage an increased use of bikes and walking. These interventions aim at changing people's travel behaviour towards more sustainable and more active transport modes. In health-related studies, TTM is used to help people walk or bike more instead of using the car. Most intervention studies aim to reduce car trips for commute to achieve the minimum recommended physical activity levels of 30 minutes per day. By reducing single occupied motor vehicle and replacing them with so called sustainable transport (public transport, car pooling, biking or walking), greenhouse gas emissions can be reduced considerably. A reduction in the number of cars on our roads solves other problems such as congestion, traffic noise and traffic accidents. By combining health and environment related purposes, the message becomes stronger. Additionally, by emphasising personal health, physical activity or even direct economic impact, people see a direct result from their changed behaviour, while saving the environment is a more general and effects are not directly noticeable.

Different outcome measures were used to assess the effectiveness of the intervention. Health-centred intervention studies measured BMI, weight, waist circumference as well as general health. However, only one of three found a significant change in general health, while BMI and other measures had no effect. However, it was also mentioned that stage based interventions are often used and implemented inadequately in practice. Thus, criticism is directed towards the use rather the effectiveness of the model itself. Looking at interventions targeting smoking cessation in pregnancy found that stage-matched interventions were more effective than non-matched interventions. One reason for this was the greater intensity of stage-matched interventions. Also, the use of stage-based interventions for smoking cessation in mental illness proved to be effective. Further studies, e.g. a randomized controlled trial published in 2009, found no evidence that a TTM based smoking cessation intervention was more effective than a control intervention not tailored to stage of change. The study claims that those not wanting to change (i.e. precontemplators) tend to be responsive to neither stage nor non-stage based interventions. Since stage-based interventions tend to be more intensive they appear to be most effective at targeting contemplators and above rather than pre-contemplators. 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 2014 Cochrane systematic review concluded that research on the use of TTM stages of change "in weight loss interventions is limited by risk of bias and imprecision, not allowing firm conclusions to be drawn". This proposal suggests the use of processes without reference to stages of change.

West claimed that the model "assumes that individuals typically make coherent and stable plans", when in fact they often do not.

Within research on prevention of pregnancy and sexually transmitted diseases, a systematic review from 2003 comes to the conclusion that "no strong conclusions" can be drawn about the effectiveness of interventions based on the transtheoretical model. Again this conclusion is reached due to the inconsistency of use and implementation of the model. Studies with which focused on increasing physical activity levels through active commute however showed that stage-matched interventions tended to have slightly more effect than non-stage matched interventions. In diabetes research the "existing data are insufficient for drawing conclusions on the benefits of the transtheoretical model" as related to dietary interventions. Again, studies with slightly different design, e.g. using different processes, proved to be effective in predicting the stage transition of intention to exercise in relation to treating patients with diabetes.

TTM has generally found a greater popularity regarding research on physical activity, due to the increasing problems associated with unhealthy diets and sedentary living, e.g. obesity, cardiovascular problems. However, there has yet to be a consensus on the efficacy of TTM for this purpose. For example, a 2014 Cochrane Systematic Review found only three studies met their inclusion criteria, and the studies included were of such "variable methodological quality" that conclusions could not be drawn without further research. More studies have been published on this subject since the 2014 review, including some which suggest TTM could be helpful, but as of October 2025, Cochrane has not yet produced an updated meta-analysis to consider new findings.

Similar criticism regarding the standardisation as well as consistency in the use of TTM is also raised in a 2017 review on travel interventions. Furthermore, there was "scant evidence of sequential movement through discrete stages". Due to the variations in use, implementation and type of research designs, data confirming TTM are ambiguous. More care has to be taken in using a sufficient amount of constructs, trustworthy measures, and longitudinal data. 1992, and 1997