By 2030, the older adult population (age 65+) will represent 21% of the total US population (US Census Bureau, 2018). Yet with aging and increased longevity, organ systems decline. The results of poor lifestyle choices further negatively impact the body's systems, and risks for chronic diseases rise (Hung et al, 2011). Diet represents a lifestyle factor that is linked to multiple chronic health conditions, including sarcopenia, type 2 diabetes, hypertension, heart disease, some cancers, and osteoporosis (Greene et al, 2004; Alemán-Mateo et al, 2014; Loenneke et al, 2016; Chanet et al, 2017; Norton et al, 2017). One suggested intervention for helping individuals to improve their health, via changes in diet, is health coaching (Olsen and Nesbitt, 2010). Research using behaviour change theories in conjunction with coaching interventions has provided successful strategies to support behaviour changes. It has been shown that dietary modifications can prolong or prevent the onset of chronic disease including, for example, increasing protein intake to reduce the risk of sarcopenia (Alemán-Mateo et al, 2014; Chanet et al, 2017; Kim et al, 2015).
Sarcopenia is a progressive skeletal muscle disease that, although more common in older adults, can present earlier in life. The condition is characterised by reductions in muscle strength, function, and mass (Cruz-Jentoft et al, 2019) and is associated with multiple adverse outcomes, including increased risk of falls, fractures, physical disability, and mortality (Jackson et al, 2018). In the USA, in 2000, the estimated direct healthcare cost attributable to sarcopenia was 18.5 billion (Janssen et al, 2004). An ICD-10 diagnosis code, M62.84, designated for sarcopenia in the USA in 2016 (Anker et al, 2016), now enables physicians and nurse practitioners to diagnose the condition and help individuals make the appropriate lifestyle changes. Two such lifestyle changes are thought to include consumption of adequate amounts of dietary protein and resistance exercise (Cruz-Jentoft et al, 2019).
Synthesis preparation
Pound and Campbell (2015) proposed a process of synthesis preparation; extracting, clarifying and summarizing the parts of the aforementioned theories/models that are most relevant are described hereafter. Specifically, as part of this synthesis, these three theories and the dietary intervention research using coaching to successfully promote dietary changes to prevent or manage chronic conditions will be discussed.
Models
Transtheoretical Model
The Transtheoretical Model (TTM), developed by Prochaska and Velicer (1997), comprises four core constructs—the six stages of change, the ten processes of change, decisional balance, and self-efficacy—and seven assumptions. When using the TTM to support behaviour change, the role of the health professional is to align the individual with the appropriate stage of change (Prochaska and Velicer, 1997). Described this way:
‘A tailored intervention approach “custom fits” message content to each individual within a targeted group based on individualized assessment along with variables believed to be important in the behaviour change process’
Purposeful pairing of the selected process(es) with the current stage of change enables the tailoring of interventions to effective changes in dietary behaviours (Prochaska and DiClemente, 1982; Prochaska et al, 1988; Prochaska et al, 1992; Prochaska and Velicer, 1997).
The use of the TTM with coaching interventions has been shown to produce positive diet-related behaviour changes that are important for disease prevention and management. Specifically, coaching interventions (delivered by trained professionals and guided by TTM) in the studies were tailored to the individual and their stage of change and successfully promoted and maintained dietary behaviour changes in adults (Clark et al, 2005; Greene et al, 2008; Clark et al, 2011; Clark et al, 2019). In a study involving adults with type 2 diabetes, for example, all four core constructs of TTM were employed along with telephone coaching (provided solely by the nurse researcher as one of the interventions) to decrease cardiovascular disease risk (Kim et al, 2011). Participants in the intervention group, who received exercise and diet guidance and one-on-one coaching, exhibited significant improvements in serum triglycerides, glucose, and HbA1c levels (Kim et al, 2011).
Social Cognitive Theory
The Social Cognitive Theory (SCT) developed in 1977 posits a relationship between three factors: personal cognitive, environmental, and supporting behavioural, which are dynamic and key to behaviour change (Bandura, 1977; Kelder et al, 2015). The term for this dynamic, interlocking interaction is reciprocal determinism (Bandura, 1978). There are 11 total constructs linked to these three factors associated with behaviour change (Bandura, 1986). Self-efficacy, the seminal and unifying construct of SCT, represents the belief that a person has in their own abilities to arrange and execute the actions required to achieve a given level(s) of attainment (Bandura, 2000). Anticipating behaviour and associated changes are influenced by what Bandura (2001) refers to as human agency. The three modes of human agency are personal, proximal, and collective. Each of the three modes serves the three factors and their associated constructs supporting SCT's infrastructure. To maximise and maintain efficacy, individuals (or groups) must be aware of their current behaviour(s) that need to change, decide to make a change(s), and then evaluate the change(s) made and adjust or maintain accordingly. SCT provides a framework to discover what motivates people and provides the pathway to elicit the desired behaviour change (Bandura, 2004).
SCT has been used successfully in research related to disease management involving coaching interventions to facilitate dietary changes (Cha et al, 2014; Schneider et al, 2016; Rankin et al, 2017). SCT, for example, was used in a pilot study designed to improve dietary behaviours in over 200 adults with prediabetes (defined in the study as someone with either impaired fasting glucose (100–125 mg/dl), or an HbA1c of 5.7–6.4%) (Cha et al, 2014). Rankin et al (2017) also used SCT as the guiding framework to coach adults to improve dietary choices. The study's results showed self-regulation, self-efficacy, and social support were paramount to participants in making dietary changes (Rankin et al, 2017).
Lastly, in a study conducted by Schneider et al (2016), coaching, which provided ongoing feedback, support, and goal setting, successfully helped participants change selected dietary behaviours and improved self-efficacy scores guided by SCT.
Theory of Integrative Nurse Coaching
The Theory of Integrative Nurse Coaching (TINC) is a middle-range nursing theory that was developed:
‘To assist nurses to more fully implement theory-guided and evidence-based nurse coaching practice, education, research, and healthcare policy through a nursing lens.’
There are three concepts, nine assumptions, and five theoretical niches (Dossey et al, 2015). The three concepts, which are derived from the Theory of Integral Nursing, are healing, metaparadigm in nursing theory, and the six patterns of knowing (Dossey, 2008). Although not an identified key concept, the importance of self-efficacy for the nurse coach and their clients/patients to deliver and receive optimal care in a reciprocal relationship is addressed, encouraged, and found within its components (Dossey et al, 2015). Nurse coaching involves interventions that are integrative to what clients/patients desire and what they are most receptive to engage in for success. For example, nurse coaching interventions may include, but are not limited to: client assessments, goal setting, motivational interviewing, open-ended questions, and probing questions (Dossey, 2015).
Although not framed by the TINC, studies have implemented nurse-led coaching interventions that have led to positive dietary behaviour changes in those with diabetes and heart disease (Vale et al, 2003; Whittemore et al, 2004; Bray et al, 2008). These studies will serve as examples of evidence-based nurse coaching interventions. Specifically, nurse-coach interventions have been shown to improve diabetes self-management and psychosocial outcomes in women with type 2 diabetes (Whittemore et al, 2004). Coaching by certified registered nurse diabetes educators was also shown to effectively guide individuals with diabetes to significantly improve dietary behaviours and blood glucose control (Bray et al, 2008). Coaching interventions have also been used to help individuals with coronary heart disease make changes to improve total blood cholesterol levels, with secondary outcomes related to physical, nutritional, and psychological factors (Vale et al, 2003). Significant improvements in the targeted risk factors were observed in participants who received the coaching intervention compared with participants receiving usual care (Vale et al, 2003). This indicates nurse-led coaching interventions help to foster positive dietary behaviour change in at-risk populations, and use of the TINC may be a best-fit theoretical framework to consider in future research.
Synthesis
The three theories presented have converging and diverging components, which will be compared and contrasted in order to synthesise these findings. Synthesising theories involves an immersion of these respective points to allow for a deeper analysis and exploration of their meanings for consideration in future research (Pound and Campbell, 2015).
Converging components
Several converging components exist among these theories. Despite differences in their respective grounding disciplines (TTM and SCT in psychology and TINC in nursing), they converge on their foundations for behaviour change. This includes complex concepts/constructs, assumptions, and niches providing theoretical guidance for nurses and other disciplines to consider with regard to encouraging desired dietary behaviour change in at-risk populations. They use coaching interventions to educate and empower individuals that lead to successful dietary behaviour changes. The TTM and SCT in conjunction with coaching interventions enabled disease prevention (Clark et al, 2005; Greene et al, 2008; Cha et al, 2014; Schneider et al, 2016) disease management (Kim et al, 2011) and maintenance of dietary behaviour changes (Clark et al, 2011; Rankin et al, 2017; Clark et al, 2019) in at-risk populations. Lastly, and perhaps most importantly, they share a vested interest in participants having a sense of self-efficacy in order to achieve desired dietary behaviour changes. The concept of self-belief (efficacy) defined by Bandura (1977) reflects cognitive processes having the ability to mediate change. These processes can be induced and altered most readily by experience of mastery that comes from proper performance, which may be augmented by coaching interventions guided by theoretical frameworks. Self-efficacy is a key concept for TTM, the seminal concept of SCT, and a major component in TINC.
Diverging components
These theories also have diverging points. The TTM provides a structured, detailed prescription for behaviour change. With the TTM framework, success is evaluated by the model's stages of change, which are based on readiness and custom-fit interventions tailored to each individual leading to behaviour change and maintenance (Prochaska and Velicer, 1997). The SCT values reciprocal determinism of person, environment, and behaviour focusing on what motivates individuals to change and establishes a pathway for success (Bandura, 1977; Kelder et al, 2015). The TINC posits behaviour change is brought about by nurse coaching strategies that empower the client/patient through integrative interventions. However, unlike the TTM and SCT, although several studies have used nurse-led coaching interventions (Vale et al, 2003; Whittemore et al, 2004; Bray et al, 2008), there is a gap in the literature related to the use of TINC as the theoretical framework.
These models converge on their use of coaching interventions related to eliciting behaviour changes and on their foundations for behaviour change. They diverge with regard to their discipline and their coaching implementation strategies, which all allow for successful dietary behaviour change.
Synthesis refinement
Each of these theories bring concepts, constructs, assumptions, and theoretical niches for nurses to consider implementing when selecting a framework to guide research, specifically related to improving dietary behaviour to prevent or prolong the onset of disease, such as sarcopenia. Through the process of synthesising three behaviour change model/theories in conjunction with their coaching frameworks, a conceptual connection was discovered. Self-efficacy is one of the four constructs of the TTM (Prochaska and Velicer, 1997), it is the seminal construct of SCT (Bandura, 1977), and the TINC posits the importance of self-efficacy for the nurse coach and their clients/patients to deliver and receive optimal care in a reciprocal relationship (Dossey et al, 2015). The concept of self-efficacy appears to be the anchor that serves as the root of all three theories, which led to successful dietary behaviour change with the use of coaching interventions (Bandura, 1977; Prochaska and Velicer, 1997; Dossey et al, 2015) (see Table 1). Self-efficacy is a transcending and powerful source of participant success as shown by the aforementioned studies when coaching strategies are implemented. Self-efficacy represents the belief that a person has in their own abilities to arrange and execute the actions required to achieve a given level(s) of attainment (Bandura, 2000). An individual will engage in a behaviour if they believe they have the ability to do so and believe the behaviour will enhance their wellbeing (Bandura, 1977).
| Transtheoretical Model (TTM) | Social Cognitive Theory (SCT) | Theory of Integrative Nurse Coaching (TINC) |
|---|---|---|
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Constructs
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Constructs
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Concepts
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Theories of behaviour change for nursing practice
The TTM and SCT represent strong frameworks that have been used to successfully guide coaching-based interventions designed to encourage dietary behaviour changes. Although nurse-led coaching interventions have been successfully used, a gap in the literature was found for evidence-based studies employing the TINC, most likely because it is still in its infancy. An investigation of the use of theories (nursing-based or other) in research found that only 38% of the research-based articles used theories developed by nurse scientists, and, of those, 55% were nursing theories, and the remaining 45% were borrowed theories (Bond et al, 2011). Future nurse scientists may consider using a theoretical framework or formally integrating theory into their research as a best practice. Implementing theoretical frameworks in order to prompt behaviour change allows nurses and other disciplines to ‘inform best practice and ensure that health professionals are using evidence-based strategies to help patients change their behavior’ (Barely and Lawson, 2016: 924).
Summary
The evaluation of each framework led to the discovery of an existing conceptual connection. This conceptual connection, self-efficacy, appears to be the anchor of successful dietary behaviour changes achieved by the power of coaching at-risk individuals for disease prevention and chronic condition management within the studies presented.
Using any one of these frameworks in conjunction with coaching interventions provides navigational resources nurses can use, alone or in collaboration with other disciplines, to assist their patients to reach optimal nutrition and improved health outcomes (Vale et al, 2003). These behaviour change models/theories offer an opportunity for researchers to choose a best fit model/theory that suits the aims of a study seeking to bring about dietary behaviour changes while meeting the needs of the participants.