Problems with the Transtheoretical Model of Behaviour 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