Critique of Transtheoretical Model of Behavior Change

1. Problems with the Transtheoretical Model of Behaviour Change Robert West University College London January 2009

2. Reading • The material in this presentation is covered in: • West, R., Time for a change: putting the Transtheoretical (Stages of Change) Model to rest. Addiction, 2005. 100(8): p. 1036-9. • West, R., The transtheoretical model of behaviour change and the scientific method. Addiction, 2006. 101(6): p. 774-8. • and associated commentaries

3. Questions? • What is the TTM? • What are the implications of the TTM for promoting behaviour change? • What evidence is claimed to support the TTM? • What are the problems with the TTM and the evidence? • Why is the TTM popular? • What is an alternative to the TTM? • What are the implications of one of this alternative? • Reading

4. The TTM • There are 5 ‘stages’ of behaviour change • Pre-contemplation • not intending to change within the next 6 months • Contemplation • intending to change between 1 and 6 months • Preparation • intending to changing within the next month • Action • in the process of changing • Maintenance • having succeeded in changing for at least 6 months • Behaviour change involves moving forward through the stages up to the action stage at which point reversion to a previous stage is common, but with repeated attempts maintenance can be achieved • Processes of successful change from one stage to another vary according to stage

5. Implications of the TTM • Interventions to promote behaviour change should match techniques to the current stage of the individual to move them to the next stage • Forward movement through pre-action stages is a worthwhile goal

6. Evidence claimed to support the model • Individuals further along the stages towards maintenance are more likely to have undergone behaviour change at follow-up • Individuals in different stages report having used different behaviour change processes to get there • Stage-matched interventions have proved successful in promoting behaviour change

7. Problems with the model and evidence • ‘Stages’ as defined do not exist in any meaningful sense • Whereas individuals clearly differ in desire to change and this is quite stable over time, intentions are fluid • Transition through pre-action stages is not the norm or necessary for successful change • Many (in the case of smoking cessation at least 50%) of change attempts involve no prior planning and such attempts are at least as likely to succeed as those that involve pre-planning

8. Problems with the model • The change process is much more dynamic, heterogeneous and stimulus-driven than is implied by the model • Attempts at change are made, suspended, abandoned and re-instated in a much more dynamic manner than the model implies; the nature of the intention regarding change is also variable (e.g. ‘cutting down on smoking’, ‘stopping’, ‘only smoking in the evening etc.) • The emphasis on processes of change is on conscious decision making factors and the model underplays key determinants of success at change such as habit and addiction • Studies have repeatedly found that a simple ‘addiction’ model is more successful at predicting successful change than ‘stage of change’

9. Problems with the model • Pre-action stage of change has not been found to be better than simple ratings of desire to change in predicting change at follow-up • The Inter 99 study appears to be the only study thus far comparing Stage of Change and simple rating of desire for change in predicting change and finds desire to be at least as good • TTM-based interventions have not been found to be more successful than other methods at promoting behaviour change • Systematic reviews conducted by third parties have not found TTM-based interventions to be more effective than other methods when it comes to actual behaviour change, though some by proponents of TTM have interpreted their results as showing a positive benefit of TTM approaches

10. Why the model continues to be popular • No formal studies on this but possible explanations are: • it provides a simple box-type model that is easy to understand and fits with commonsense ideas • many of its propositions are easily studied • it allows for positive conclusions to be drawn about interventions even when these have not resulted in behaviour change

11. An alternative model (SNAP model) • Individuals vary over time and between each other in their desire (want or need) to change their behaviour • Events occur that occasionally raise that desire momentarily to a point where they decide to make a change, either immediately or at some point in the future • When they implement that intention they form a ‘rule’ concerning the new behaviour pattern; this rule can vary (e.g. I will never smoke again, I will try not to smoke etc.) • This rule adds to any existing needs to engage in the new behaviour in the face of competing wants and needs to revert to the old behaviour • If the desire to engage in an instance of the old behaviour is greater than the need not to there will be a ‘lapse’ (the old behaviour will occur but the rule regarding change will still be in place) • If the old behaviour becomes manifest to such a degree that the rule is not longer tenable it will be changed or abandoned (‘relapse’)

12. The SNAP model • 4 states • Staying the old behaviour (with no immediate plans to change) • New behaviour engagement (applying a rule defining the new behaviour) • Attempting (apply a rule of ‘trying’ to follow the new behaviour pattern) • Planning to change (definite plans to make the change in the near future) • Transition can occur between any state and any other • Transition occurs when the desire (want or need) to move at that moment is greater than the desire to remain • Behaviour does not follow the rule when the desire to engage in the behaviour is greater than the desire to preserve the rule • Rules with clear boundaries are important in generating wants and needs that prevent lapses and reducing wants and needs to revert

13. The process of stopping smoking SNAP: 4 states based on the rules smokers apply to themselves • A quit attempt is a rule in which smokers define themselves as • attempting (‘I am trying not to smoke’) • not smoking (‘I have stopped smoking’) • Smokers plan a quit attempt when • the feeling of ‘want’ or ‘need’ to stop at a future date exceeds the desire to continue • Smokers make a quit attempt when • the want or need to stop now exceeds the want or need to carry on smoking • Smokers lapse when • the want or need to smoke at a given moment exceeds the want or need to remain abstinent • the ‘not smoking’ rule is still in force • Smokers relapse when • the want or need to abandon the quit attempt exceeds the want or need to continue with it Smoking Pre-quit Planning Attempting Not Smoking Post-quit

14. Implications of the SNAP model • Readiness to change is a state, not a stage • Interventions to promote attempts at change should focus on triggering immediate action where possible in all recipients • The focus in initiating change should always be on maximising the immediate ‘want’ (anticipated pleasure or satisfaction) or ‘need’ (anticipated relief) to make the change • The focus in maintaining change should always be on maximising the strength and frequency of want and need to maintain the new behaviour pattern and minimising the want and need to revert • The nature of the ‘rule’ about the new behaviour is important to maintenance (needs to set clear boundaries and specific actions)

15. Implications of the SNAP model • Desire to quit should be more stable than intention • Short-term intention and desire should predict attempts to change better than either alone • Different factors will come into play in promoting or preventing change with different behaviours. In the case of smoking, for example, indices of addiction (e.g. time to first cigarette of the day) will be a better predictor or success of attempts to stop than desire to stop or commitment to stopping