Foundational knowledge - Traditional Theories and Models of Behavior Change

1. Introduction

The theories most used in lifestyle interventions with good scientific results are Social Cognitive Theory (SCT), Theory of Planned Behavior (TPB), The Health Belief Model (HBM) and the Trans-Theoretical Model (TTM) (Salwen-Deremer et al., 2019). However, other behavior change theories exist, but they are not widely supported according to the latest research, so their results cannot be generalized (Salwen-Deremer et al., 2019).

2. Social Cognitive Theory (SCT)

Social Cognitive Theory (SCT) claims that there is a reciprocal relationship among the person, their behavior and the environment. This theory emphasizes on social influence and the importance of external and internal social reinforcement (Bandura, 1996). The SCT has the following components that need to be addressed when designing health change interventions and behaviors:

1. Reciprocal Determinism is the central concept of SCT. It refers to the dynamic and reciprocal interaction of a person (individual with a set of learned experiences), the environment (external social context), and the behavior (responses to stimuli to achieve goals) (Bandura, 1996).
2. Behavioral Capability refers to a person's actual ability to perform a behavior through essential knowledge and skills. To accomplish the desired behavior, the person must have the knowledge to do it. People learn from both the consequences of their behavior and the environment in which they live (Bandura, 1996).
3. Observational Learning means that people can witness and observe a behavior conducted by others and then reproduce those actions, a concept called "modelling" of behaviors. If people see a successful demonstration of behavior, they can also perform the behavior successfully (Bandura, 1996).
4. Reinforcements refer to the internal or external responses to a person's behavior that affect the probability of continuing or discontinuing the behavior. Reinforcements can be initiated by the person or existent in the environment, and reinforcements can be positive or negative (Bandura, 1996).
5. Expectations refer to the anticipated consequences of a person's behavior. People anticipate the consequences of their actions before engaging in the behavior, and these consequences can influence the successful completion of the behavior. Expectations derive primarily from previous experiences, and they focus on the value placed on the outcome and are subjective to the individual (Bandura, 1996).
6. Self-efficacy refers to the level of a person's confidence in the ability of performing a behavior successfully. Self-efficacy is influenced by a person's specific capabilities and other individual factors and environmental factors that can be perceived as barriers and facilitators (Bandura, 1996).

Social Cognitive Theory (Bandura, 1996)

SCT and mHealth

SCT was successfully used for mHealth applications in weight loss interventions (Burke et al., 2012), promoting physical activity (Baretta et al., 2019; Freigoun et al., 2017), chronic disease management (Whittemore et al., 2020), and smoking cessation (Ghorai et al., 2014).

3. Theory of Planned Behavior (TPB)

Theory of Planned Behavior (TPB) intends to explain all behaviors over which people can employ self-control, and it is an extension of the Theory of Reasoned Action (TRA) (Ajzen, 1991). The key component of the model is behavioral intent. Behavioral intentions are shaped by the attitude about the likelihood of the behavior to have the expected outcome and by the subjective evaluation of the risks and benefits of the desired outcome (Ajzen, 1991). The TPB implies that achieving a specific behavior depends on motivation (intention) and ability (behavioral control). It makes the difference between three types of beliefs - behavioral, normative, and control. The TPB contains six constructs that collectively represent people’s actual control over the behavior.

1. Attitudes refer to a person's degree to have a favorable or unfavorable evaluation of the behavior of interest. It requires the person to consider the outcomes of performing the behavior (Ajzen, 1991).
2. Behavioral intention refers to the motivational factors that influence a given behavior. If the intention to perform the behavior is strong, the behavior will most likely be performed (Ajzen, 1991).
3. Subjective norms refer to the thoughts about whether most people approve or disapprove of the behavior. It relates to a person's beliefs about whether peers and people of importance think they should engage in the behavior (Ajzen, 1991).  
4. Social norms refer to the specific behaviors of a group of people or a larger cultural context. Social norms are considered usually to dictate in a group of people (Ajzen, 1991).
5. Perceived power refers to the perceived presence of factors that may facilitate or impede the performance of a behavior. Perceived power contributes to a how a person perceives behavioral control over each of those factors (Ajzen, 1991).
6. Perceived behavioral control refers to a person's perception of how easy or difficult is to perform a specific behavior. Perceived behavioral control may vary across situations and actions,  resulting in multiple perceptions of behavioral control depending on the situation (Ajzen, 1991).

Theory of Planned Behavior (Ajzen, 1991)

TPB and mHealth

TPB was successfully used for mHealth in preventing alcohol abuse (Kazemi et al., 2017), diabetes management (Samer & Al-Shami, 2020), dietary weight loss and physical activity (Salwen-Deremer et al., 2019), and coping with chronic diseases (Guido et al., 2018).

4. The Health Belief Model (HBM)

The Health Belief Model (HBM) implies that a person's belief in a threat of an illness or disease coupled with a person's confidence in the effectiveness of the recommended health behavior or action will predict the likelihood the person to adopt the behavior (Ogden, 20112). HBM is composed of six constructs, as follows:

1. Perceived susceptibility refers to a person's subjective perception of the risk of developing an illness or disease. There is wide variability of how people perceive the chances of developing a disease (Ogden, 20112).
2. Perceived severity refers to a person's feelings on how severe an illness will be. When evaluating the severity, a person often considers the health consequences (e.g., disease or death) and social consequences (e.g. social relationships) (Ogden, 20112).
3. Perceived benefits refers to a person's assessment of the effectiveness of behaviors to reduce the threat of disease. The course of action in preventing (or curing) the disease is based on the perception that action is beneficial (Ogden, 20112).
4. Perceived barriers refers to a person's thoughts on the obstacles to performing a recommended health action. The person evaluates the usefulness of the actions against the idea that it may be expensive, dangerous, unpleasant, time-consuming, or inconvenient (Ogden, 20112).
5. Cue to action refers to the stimulus needed to trigger the decision to accept a recommended health action. The cues can be internal (disease symptoms.) or external (e.g., advice from others, illness of someone close newspaper article, etc.) (Ogden, 20112).
6. Self-efficacy refers to the person's confidence in their ability to undertake the behavior (Ogden, 20112).

Health Belief Model (Ogden, 20112)

HBM model was found to be successful in mHealth apps targeting HIV testing (Evans et al., 2016), screening for cervical cancer (Khademolhosseini et al., 2017), tobacco control (Ali et al., 2020), and tracking infectious diseases – such as COVID-19 (Michel et al., 2020).

5. Trans-Theoretical Model (TTM)

Trans-Theoretical Model (TTM) focuses on the decision-making of the individual and is a model of intentional change, considering that people do not change behaviors quickly (Prochaska, 2013). The TTM states that a person moves through different stages when modifying behavior. Various intervention strategies are most effective at each stage to move the individual to the next step (Prochaska, 2013). The TTM stages are:

1. Precontemplation
   In this stage, people do not desire to take action and are often unaware that their behaviors negatively affect their health (Prochaska, 2013).
2. Contemplation
   In this stage, people recognize that their behavior may influence their health. Even with this recognition, people may still feel ambivalent toward changing their behavior and may not take action towards it (Prochaska, 2013).
3. Preparation (Determination)
   In this stage, people are determined to take action and start taking steps toward behavior change (Prochaska, 2013).
4. Action
   In this stage, people have just changed their behavior, which is considered to be within 6 months of actively pursuing the behavior (Prochaska, 2013).
5. Maintenance
   In this stage, people sustain their behavior for more than 6 months and intend to maintain the behavior change. People in this stage actively work to prevent relapse to earlier stages (Prochaska, 2013).
6. Termination
   In this stage, people will not return to their unhealthy behaviors. Since this is rarely reached, this stage is often not considered in health promotion programs (Prochaska, 2013).

Trans-Theoretical Model (Prochaska, 2013)

TTM has successful results in mHealth application on obesity prevention (Lee et al., 2017), diabetes prevention (Jennings et al., 2019), mental health (Frith & Loprinzi, 2017), eating behavior (Abdel-Fatah Ibrahim et al., 2017), and smoking cessation (Chahar et al., 2018).