Transtheoretical Model - TTM Criticisms

TTM Criticisms

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."
  • 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.
• 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."