Practicality vs. Validity in the Transtheoretical (‘Stages of Change’) Model (Copy)
Background
The transtheoretical model describes behaviour change as a process with 5 stages, thus giving rise to its colloquial shorthand, the Stages of Change model. These stages are precontemplation, contemplation, preparation, action and maintenance. The model proposes that while individuals typically move through them in sequence, they can still relapse to a prior stage. Each stage is characterised by certain thoughts and actions, and it has most commonly been applied to smoking cessation within health psychology, as described in the Figure below [1].
How it’s used.
By categorising individuals into distinct stages, health care practitioners can derive interventions tailored towards how far along the individual is in their behaviour change journey, as proposed by the model.
Criticisms over its validity.
Firstly, one of the harshest criticism towards the model is how arbitrarily defined the stages are. Could a matter of how many days or months an individual has been in a certain stage translate to actual readiness to perform the target behaviour? Arbitrarily sorting individuals into stages has serious implications for what treatment or intervention they are assigned. In the worst-case scenario, some may miss out on getting any help at all if they are sorted into the Precontemplation stage. Secondly, academics have highlighted that the model does not consider other factors beyond conscious planning, such as the role of habits or reward and punishment– both of which are key processes within addiction that need to be addressed [2]. Thirdly, if the model were valid, those in the maintenance phase should be more likely to achieve their targeted behaviour, yet follow-up studies do not always find this to be the case [3]. Lastly, examination of studies supporting the model reveal their methods to be lacking; for example, participants who complete self-report questionnaires on which stage they’re in may unknowingly rank themselves as more prepared than in actuality [4].
Claims of its practicality.
Nonetheless, the model has gained success because differentiating individuals into stages is cost-effective for designing interventions. Policymakers, marketing teams and healthcare systems prefer neat segmentation of audience members, and the model improves the chances of different populations receiving more appropriate treatment [5]. Importantly, most psychological health instruments (e.g. the Beck Depression Inventory and the Autism Spectrum Quotient test) have man-made cut-off points and constantly face the question of whether this reflects a ‘true’ diagnosis.
In sum, if the model is used for practical purposes, it should be with caution or perhaps alongside other instruments. As always, a ‘stage’ is only a small piece of the picture that makes up someone attempting to change their behaviour.
References:
[1] Prochaska, J. O., Velicer, W. F., DiClemente, C. C., & Fava, J. (1988). Measuring processes of change: applications to the cessation of smoking. Journal of Consulting and Clinical Psychology, 56(4), 520.
[2] West, R. (2005). Time for a change: putting the Transtheoretical (Stages of Change) Model to rest. Addiction (Abingdon, England), 100(8), 1036-1039.
[3] Littell, J. H., & Girvin, H. (2002). Stages of change: A critique. Behavior Modification, 26(2), 223-273.
[4] De Nooijer, J., Van Assema, P., De Vet, E. & Brug, J. (2005) How stable are stages of change for nutrition behaviors in the Netherlands? Health Promotion International, 20, 27–32.
[5] Armitage, C. J. (2009). Is there utility in the transtheoretical model?. British Journal of Health Psychology, 14(2), 195-210.