Non-adherence patterns for cardiovascular disease (CVD) treatment are associated with increased healthcare costs and worse outcomes.1,2 While most data on the impact of non-adherence comes from industrialized countries, most people with CVD live in low- and middle-income countries where adherence problems and their consequences are exacerbated by economic conditions.3 In previous articles, we have examined several behavioral theories to understand the mechanisms of patient treatment adherence behavior. The different theories encompass six theoretical perspectives: biomedical, behavioral, communication, cognitive, self-regulation, and stages.4 Cognitive and stage perspectives are the most frequently discussed theories in the academic literature. Cognitive theories such as the Theory of Planned Behavior (TPB), previously discussed in this series, examine how attitudes and beliefs drive behavior. Stage-based theories contend that people learn, develop, and change their behavior according to discrete steps. Cognitive and stage-based models can be effectively used together; cognitive theories provide insight on why people change their behavior, and stage-based perspectives generate insights on how the change is implemented. The Transtheoretical Model (TTM), also known as the Transtheoretical Stages of Change model, is the most prominent and widely applied stage model.4 It is different from many other prominent behavioral models; it was specifically designed not only to describe the change process but also to facilitate change toward healthier actions.5 The TTM has been applied to a wide range of health behaviors, and it can easily be tailored to assess therapy adherence for patients with CVD and provide them with personalized feedback to improve their adherence to treatment and overall outcomes.
The first version of the TTM was proposed in the 1980s by James Prochaska and Carlo DiClemente, who focused on nicotine addiction; since then, it has been applied to a number of different health behaviors.4,6,8
The TTM consists of two major components: stages of change and processes of change. The stages of change are at the core of the model and portray an individual’s actual readiness and willingness to change according to five distinct steps. Applying these stages to a hypertension patient might look like this:
Progression through the stages is represented here as linear, but in application, it may be cyclical. Due to the nature of behavioral change, there is a potential for individuals to regress as well as advance. For example, hypertensive patients in the Action stage who have been adherent for some months may become non-adherent and fall back to the Preparation or even Contemplation stages.6 They do not, however, typically fall back to Precontemplation because this would imply that they have forgotten why they were following recommendations in the first place. Patients who regress in their behavior are often easy to get back on track.
The processes of change facilitate the transition from one stage to the next and are classified as being either experiential or behavioral.
The TTM can serve as a helpful tool for providers to assess patient adherence and provide useful feedback or suggestions as needed. For example, consider a typical patient with hypertension. At his appointment, the doctor asks a few targeted questions regarding his therapy, including:
The patient’s answers reveal that he does not strictly adhere to his treatment recommendations and is unaware that this is problematic. Because hypertension symptoms are not manifest, the benefits of adherence are not obvious. The doctor can then use the Health Belief Model to guide the discussion and provide information on the risks of uncontrolled hypertension and the benefits of following the therapy regimen. The patient, now aware of the benefits of adherence, may consider changing his behavior and progress into the Contemplation phase via this consciousness raising process.
The TTM is a widely used tool and can supplement other health models such as the TPB and the Health Behavior Model by facilitating behavior changes and tracking progress through the stages. It may be particularly useful in informing the way that adherence information is provided to the patient and influence the design of adherence interventions. The TTM has been successfully used to address non-adherence to antihypertensive and lipid-lowering treatments7; studies demonstrate that patients respond well to the individualized feedback informed by the TTM.6 However, TTM-based interventions are not always more effective than other reasonably designed approaches,5 and health behavior research increasingly prioritizes more recent behavioral models, such as COM-B, and other developments in behavioral theory that will be discussed in other articles. These models are complimentary and provide important insights into the patient journey.
1. Shalini Lynch (2019). “Adherence to drug treatment,” MSD Manual Consumer Version, August 2019. https://www.msdmanuals.com/home/drugs/factors-affecting-response-to-drugs/adherence-to-drug-treatment
2. Ian M. Kronish & Ye Siqin (2013). “Adherence to cardiovascular medications: Lessons learned and future directions,” Progress in Cardiovascular Diseases, (55):6, pp. 590–600. https://doi:10.1016/j.pcad.2013.02.001
3. Tracey-Lea Laba et al. (2013). “Strategies to improve adherence to medications for cardiovascular diseases in socioeconomically disadvantaged populations: A systematic review,” International Journal of Cardiology, (167):6, pp. 2430–2440. https://doi:10.1016/j.ijcard.2013.01.049
4. Lamyae Sardi et al. (2019). “Applying trans-theoretical model for blood donation among Spanish adults: A cross-sectional study.” BMC Public Health, (19):1, p. 1724. https://doi:10.1186/s12889-019-8046-9
5. David Taylor et al. (2006). “A review of the use of the Health Belief Model (HBM), the Theory of Reasoned Action (TRA), the Theory of Planned Behaviour (TPB) and the Trans-Theoretical Model (TTM) to study and predict health related behaviour change” London, UK: National Institute for Health and Clinical Excellence, pp. 1–215.
6. Sara Johnson et al. (2006). “Efficacy of a transtheoretical model-based expert system for antihypertensive adherence,” Disease Management, (9):5, pp. 291–301. https://doi: 10.1089/dis.2006.9.291
7. Sara Johnson et al. (2006). “Transtheoretical Model intervention for adherence to lipid-lowering drugs,” Disease Management, (9):2, pp. 102 –114. https://doi.org/10.1089/dis.2006.9.102
8. James Prochaska & Carlo C. DiClemente, (1983). “Stages and processes of self-change of smoking: Toward an integrative model of change,” Journal of Consulting and Clinical Psychology, (51):3, p. 390. https://doi: 10.1037//0022-006x.51.3.390