James H. Rimmer, Ph.D., Director

As we enter a new year, millions of people will decide that it is time to give up a bad habit such as overeating or smoking and will try to replace it with a healthy behavior such as exercising or eating a reduced number of calories. Some people will start on January 1 but quit within a few weeks, while others will make the changes last for several months, and a small number will make it to the end of the year! Why some people give up after only a few weeks while others continue to make positive changes for a much longer period remains the "black box" of health behavior. Unfortunately, many health practitioners will work diligently at trying to help a client lose weight or exercise more with minimal to no understanding of the theoretical underpinnings associated with behavior change theory.

Increasing physical activity, as well as other major life changes, is a complex and dynamic process for people with and without disabilities. In order to explain human behavior and have an influence on changing someone's behavior (i.e., starting a physical activity program), health professionals must understand the various behavior change theories. Here is a quick overview of four of the more popular theories associated with individual health behavior change (as opposed to interpersonal health behavior, which I'll discuss in next month's column).

1. Transtheoretical Model
   
   One of the most popular models of health behavior is the Transtheoretical Model (TTM). TTM states that people who are electing to change a behavior (i.e., increasing physical activity) must be placed in the stage of change that fits their current behavior. There are five stages of change - Precontemplation (do not intend to take action within next 6 months), Contemplation (intend to take action within next 6 months), Preparation (intend to take action in next 30 days), Action (have increased their physical activity for less than 6 months), and Maintenance (have maintained an adequate level of physical activity for more than 6 months). The TTM also has three other components: Decisional Balance (an individual's relative weighing of the pros and cons of changing the behavior such as increasing physical activity); Processes of Change (activities that people use to progress through the stages of change, such as making a commitment to change, wanting to learn new exercises, using social support to maintain exercise behavior); and Self-Efficacy (confidence in performing physical activity).


2. Transactional Model Stress and Coping
   
   The Transactional Model of Stress and Coping provides a structure for understanding how a person deals with various stressors in his or her life. Experts use the term, stressors, to denote the demands made by the internal or external environment that affect an individual's homeostasis. Some people who are under a great deal of stress will turn to certain substances such as alcohol, drugs, or excessive food consumption to cope with various stressors. Theoretically, the higher the level of stress, the more unlikely it is that the individual will want to engage in a healthy behavior such as physical activity, albeit exercise has been known to help people cope with the many stressors in their lives. What is intriguing about this model is that stress affects all of us to some degree, but at greatly varying intensity levels and at different times in life. Some people experience high amounts of stress to the same exposure (i.e., having difficulty with a family member or another employee, struggling with bills, loss of job, etc.), while others are able to deal with it in a much more effective way using coping strategies such as spirituality, exercise, and social interaction. Research on stress and coping among people with disabilities has emphasized that there is a significantly higher level of stress associated with the individual's impairment(s) (i.e., environmental barriers, health-related issues). Since various stressors can prevent an individual from engaging in physical activity, it is essential that health professionals identify what these stressors are and learn effective strategies for helping the individual cope with them.


3. Health Belief Model
   
   The Health Belief Model (HBM) seeks to understand why certain health behaviors are engaged in while others are not. It is one of the oldest and most popular models in health promotion. The basic concept behind the HBM is that for behavioral change to succeed, an individual must feel concerned or threatened by their current behavior (i.e., smoking, not exercising, eating poorly) and must believe that changing the behavior will be beneficial at an acceptable cost. The key areas of the HBM include: perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, and self-efficacy (which other models also include as part of the behavior change process). Each of these components has an effect on behavior and the beliefs can be measured in interviews or population-wide surveys.


4. Theory of Reasoned Action and Theory of Planned Behavior
   
   The Theory of Reasoned Action (TRA) and Planned Behavior (TPB) are similar to the Health Belief Model in the sense that they have the same underlying characteristics which are often grouped as value expectancy theories. The TRA/TPB Model was developed after the Health Belief Model and grew out of a need to understand the relationship between the individual and his or her behavior. Both TRA and TPB emphasize that motivation (intention) has a strong basis for changing behavior. The TRA contains the following components: beliefs (behavioral and normative), attitudes, intentions, and behavior. The underlying framework of TRA is that behavioral intention is affected by the individual's attitude toward performing that behavior, and that attitude is affected by the individual's beliefs about outcomes or attributes of performing the behavior and the associated outcomes. In other words, if the goal is to lose weight and the individual believes that exercise will help him or her achieve that goal, the person is more likely to engage in the activity versus someone who thinks it will not help them. The second part of TRA is that individuals who believe that important people in their lives (normative beliefs) will approve or disapprove of the behavior -- and are motivated to obtain approval from these individuals -- will hold a positive subjective norm. The Theory of Planned Behavior (TPB) is an extension of TRA with the added component of perceived behavioral control to account for factors outside of the individual's control that may affect his or her intention or behavior. For example, a person will expend more effort to perform a certain behavior such as exercise when his or her perception of behavioral control is high.

Many of the theories associated with behavior change have a common theme that encompasses people's self-efficacy and/or their motivation or desire to perform the activity if they are able to do so and perceive that it will help them. Bottom Line: it is important for individuals with disabilities and health promotion professionals who target a behavior such as increasing physical activity to understand that changing a negative behavior into a positive one requires an understanding of what drives the individual to engage in the negative behavior and what motivates them to make a change.