Motivational and Volitional Variables Associated With Stages of Change for Exercise in Multiple Sclerosis

Abstract

The main objective of this study was to determine whether motivational and volitional variables identified in the health action process approach (HAPA) model can be used to successfully differentiate people with multiple sclerosis (MS) in different stages of change for exercise and physical activity. Ex-post-facto design using multiple discriminant analysis was used. Participants were 215 individuals with MS. The outcome variable was measured by the Physical Activity Stages of Change Instrument, along with motivational and volitional measures (severity, action self-efficacy, outcome expectancy, risk perception, perceived barriers, intention, maintenance self-efficacy, action and coping planning, and recovery self-efficacy). Participants in the precontemplation, contemplation, and action groups can be maximally separated by two significant canonical discriminant functions, volition and motivation. The action group can be differentiated from other groups based on high group mean (centroid) score on the volition function, and the precontemplation group can be differentiated based on low group means on both the motivation and volition functions. The contemplation group can be differentiated based on high centroid score on the motivation function. Research findings of this study support the concept of stage-matching exercise and physical activity intervention. The HAPA framework can be used to design health promotion behavioral interventions for people with MS in vocational rehabilitation.

Keywords

multiple sclerosis physical activity motivation stages of change discriminant analysis

According to the Healthy People 2020 document, one of the greatest threats to public health in the United States is obesity (U.S. Department of Health and Human Services, 2010). Individuals with disabilities are known to have high prevalence and incidence of secondary conditions including overweight and obesity (Lynch & Chiu, 2009). Secondary conditions are health problems, if left untreated can worsen disability caused by a primary impairment (Ipsen, Seekins, & Ravesloot, 2010; Kinne, Patrick, & Doyle, 2004). Secondary conditions can also adversely affect employment outcomes of people with disabilities (Ipsen et al., 2010). Ipsen (2006) examined the relationship between employment and health behaviors using data from the Behavioral Risk Factor Surveillance System. She found that exercise/physical activity increased the probability of employment of people with physical disabilities. Based on the findings of their programmatic research in health and disability, Ipsen et al. (2010) indicated that many secondary conditions including physical deconditioning, fatigue, sleep problems, weight problems, pain, depression, and social isolation respond well to health promotion behavioral interventions.

However, previous studies of exercise and physical activity behavior of people with chronic illness and disability have been criticized for lacking a sound theoretical basis (Tulloch et al., 2009), leading to the current interest in applying health behavior change theories to improve our understanding of exercise and physical activity behavior of people with disabilities. Some of the more popular theories include social cognitive theory, the transtheoretical (stages of change) model, theory of planned behavior, self- determination theory, and protection motivation theory (Tulloch et al., 2009). These theories have found to be useful in identifying potentially important and modifiable exercise determinants for people without disabilities. However, there is a lack of research using these theories individually or collectively to study health-promoting behavior of people with disabilities including multiple sclerosis (MS). The health action process approach (HAPA), which integrates the health self-efficacy theory (Bandura, 1997), the planned behavior theory (Ajzen & Fishbein, 1980), and the transtheoretical stages of change theory (Prochaska, DiClemente, & Norcross, 1992) to predict engagement in health-promoting behavior, appears to have great potential as a motivational model for exercise and physical activity self-management for people with disabilities.

The HAPA Model and Intervention Matrix

The HAPA model was developed by Ralf Schwarzer (1992) in Germany. Specifically, the model incorporated the stages of change theory by identifying individuals who have no intention to perform (preintenders [precontemplation]), people who intend to perform (intenders [contemplation]), and those who are already performing the target health behavior (actors [action and maintenance]). Schwarzer indicates that the adoption, initiation, and maintenance of health-promoting behaviors (e.g., exercise and physical activity) can be conceptualized as a process composed of a motivation phase and a volition phase. In the motivation phase, the focus is on encouraging the preintender to form an intention to engage in health-promoting behaviors over risky or unhealthy behaviors. The concepts of self-efficacy and outcome expectancies presented in Bandura’s social-cognitive health theory are seen as major predictors of behavioral intentions. Risk awareness is also hypothesized to be associated with intentions (Schwarzer, 2008). However, to be effective, messages using fear or threat must be framed in a way that allows individuals to feel they have the abilities, skills, and coping resources to engage in a target health-promoting behavior. The motivation phase in the HAPA model is useful for describing what people choose to do, whereas the volition phase helps to describe how hard people will try and how long they will persist in a determined action.

In the volition phase, the emphasis is on helping people move from intention to action and maintenance behaviors. Based on the theory of planned behavior, the HAPA model posits that it is the volitional or self-regulatory processes that mediate between the intention and action. The volitional/self-regulatory processes can be further divided into action planning and coping planning and is hypothesized to be strongly influenced by action self-efficacy because the number and quality of action plans and the optimal use of resources are dependent on one’s perceived competence and experience. To shape a target health-promoting behavior (e.g., exercise and physical activity), the intention has to be transformed into detailed instructions of how to perform the desired action such as what exercise equipment to buy, when and how often to exercise, and when and where to exercise. Once an action has been initiated, the behavior has to be protected from being interrupted or terminated due to incompatible competing demands (e.g., a demanding work schedule, health complications), and maintenance self-efficacy determines the amount of effort that will be expanded and maintained. Coping planning will enable the individual to reengage in health-promoting behavior after any interruption of the behavior. Furthermore, both situational barriers and opportunities will affect volitional behavior. If situational cues are overwhelming, metacognitive skills and internal coping dialogues will not be sufficient to bridge the gaps between intention and action. Finally, actions are not only a function of intentions and cognitive control but are also influenced by the perceived and the actual support in the environment. The HAPA model has been validated in a series of studies and the results indicated that HAPA constructs are predictive of exercise, drinking, and diet behavior and can be used to design health promotion behavioral interventions for patients in cardiac rehabilitation and people with other chronic conditions (Schwarzer, Lippke, & Luszczynska, 2011).

Based on the HAPA model, Schwarzer et al. (2011) developed an intervention matrix to help rehabilitation health professionals to conceptualize stage-specific health promotion interventions for people with chronic illness and disability. They suggested that in the motivational phase, the preintenders could benefit from interventions that help them develop self-efficacy and deal with any unrealistic risk perception and outcome expectancies, whereas intenders would not need to be confronted as they have already set goals and have moved beyond the preintender stage. Conversely, intenders would benefit from interventions related to planning and from interventions that translate their intentions into direct action. For actors, interventions that target planning strategies aim at preventing relapse, or interventions that reinforce the maintenance of their health-promoting behavior are indicated (Schwarzer et al., 2011). The stages are not rigid in nature and allow for a variety of approaches, while the assessment of stages can be measured without adherence to specific time frames (Schwarzer et al., 2011; Sutton, 2000). The HAPA intervention model assumes that one set of social-cognitive and behavioral variables can be important in helping to move people from the preintender to intender stage, whereas a different set of variables may have stronger influence for moving individuals from the intender to the actor stage. The HAPA constructs and variables associated with each stages of change in the HAPA intervention matrix are presented in Table 1.

Table 1.

Intervention Matrix for HAPA-Based Stage-Specific Treatment

	Stage group
	Preintender	Intender	Actor
Motivational constructs
Self-efficacy (motivational)	X
Risk perception	X
Outcome expectancies	X
Goal setting	X
Volitional constructs
Action planning		x	x
Coping planning		x	x
Social support		x
Self-efficacy (maintenance)		x
Self-efficacy (recovery)			x
Action control			x

Note: HAPA = health action process approach.

Specifically, the HAPA intervention matrix specifically indicates motivational constructs (motivational self-efficacy, risk perception, outcome expectancies, and goal setting) as the focus of health promotion interventions indicated for individuals in the preintender stage. Interventions addressing issues related to the volitional constructs such as action planning, coping planning, and maintenance self-efficacy are most suitable for individuals in the intender stage. Other volitional constructs such as action planning, coping planning, recovery self-efficacy, and action control–related interventions are the best strategies that meet the cognitive mind-set of individuals in the actor stage.

Purpose of the Study

There are about 400,000 people with MS living in the United States (National Multiple Sclerosis Society [NMSS], 2012). Research has indicated that physical activity (e.g., yoga, exercise, and stretch) can ameliorate MS symptoms and secondary health problems associated with an inactive lifestyle (Bombardier, Wadhwani, & LaRotonda, 2005; Motl, 2008; Motl & McAuley, 2009; Motl, McAuley, & Snook, 2005; A. Stuifbergen, 1992; A. K. Stuifbergen & Rogers, 1997). However, how well people with MS manage their secondary conditions depends more on what they do than on what is done to them. Individuals with MS need to pay attention to their medical management, exercise, diet, stress level, and alcohol consumption, using multiple coping strategies. Unfortunately, making behavior change is notoriously difficult because maladaptive behaviors are well-rehearsed automatic behaviors. Learning and practicing adaptive health promotion self-management techniques can be challenging. Therefore, behavior changes necessary for adaptive self-management are unlikely to occur in the absence of significant motivation.

The HAPA model, which integrates the health self-efficacy theory, the planned behavior theory, and the stages of change model, has been found to predict engagement in health-promoting behaviors including exercise and physical activity and may be useful for developing health promotion behavioral interventions for people with MS (Chiu, Lynch, Chan, & Berven, 2011). However, the HAPA intervention matrix has not been validated for people with MS and other disability groups. The purpose of this study was to determine whether motivational and volitional variables identified in the HAPA model can be used to successfully differentiate people with MS in different stages of change for exercise and physical activity.

Method

Participants

Participants were 215 individuals with MS, recruited from the NMSS and the neurology clinic of a university teaching hospital in the Midwest. The inclusion criteria for participation are a MS diagnosis, age between 18 and 65, and living in the community. Ages of the participants ranged from 19 to 67 years, with a mean of 47.38 years (SD = 10.19). Most of the participants were women (n = 185, 86.0%), married (n = 152, 70.7%), and White (n = 187, 87.0%). Participants were relatively well-educated with 34.0% having some college education, 34.4% having graduated from college, and 21.4% having completed graduate school education. About 39.1% of the participants had been retired due to MS and 12.1% were unemployed, while 32.6% were employed full-time. Sixty-four (29.8%) participants were professionals, 19 were managers (8.8%), and 33 (15.3%) were in clerical or sales occupations. Ninety-three (43.3%) of the participants reported being treated for secondary health conditions (e.g., overweight, high blood pressure, high cholesterol, and diabetes).

Instrument

Minimal Record of Disability (MRD)

The MRD was developed by the International Federation of Multiple Sclerosis Societies (1984) to operationalize the construct severity of MS by evaluating MS symptoms and performance of activity of daily living. It is composed of 23 items and two subscales: (a) the Incapacity Status Scale (ISS), 16 items (e.g., “stair climbing,” “speech and hearing,” and “mood and though”), has a focus on functional disability in activities of daily living (ADL) and (b) the Environment Status Scale (ESS), 7 items (e.g., “work status,” “personal residence or home,” and “transportation”), has an emphasis on social impairment resulting from the illness. ISS items are rated on a 5-point Likert-type scale ranging from 0 (no disability) to 4 (most disability). ESS items are rated on a 6-point Likert-type scale ranging from 0 (no disability) to 5 (totally lost). The ISS with its focus on ADL was used to operationally define MS severity in the current study. Moderate intraclass correlation coefficients (ICC) were found between the MRD and the Kurtzke Functional System (KFS), ranging from .26 with the KFS sensory scale to .69 with the KFS pyramidal function scale (Solari et al., 1993). In addition, high concordance (ICC = .84) was found between the MRD and the Expanded Disability Status Scale. Cronbach’s alpha coefficients for the ISS and ESS in the present study were computed to be .90 and .90, respectively.

Center for Epidemiologic Studies Depression Scale–Short Form (CESD-10)

The CESD-10 was validated by Andresen, Malmgren, Carter, and Patrick (1994) to operationalize depressive symptomatology in the general population. The CESD-10 consists of 10 items (e.g., “I felt depressed”), and the test items are rated from the perspective of how often the respondent felt this way during the past week using a 4-point Likert-type scale of 0 (rarely or none of the time, less than 1 day), 1 (some or a little of the time, 1–2 days), 2 (occasionally or a moderate amount of time, 3–4 days), and 3 (all of the time, 5–7 days). The total score can range from 0 to 30. A score of 10 or above is indicative of depressive symptoms. Miller, Anton, and Townson (2008) reported an ICC of .85 (p < .05). Andresen et al. (1994) indicated that CESD-10 demonstrated predictive accuracy similar to the CESD-20, kappa = .97. In addition, high CESD-10 was found to correlate with poor health status scores, r = .37, p < .05, with a strong negative correlation with positive affect, r = −.63, p < .05. A test–retest reliability estimate over a 12-month interval was found to be .59. Cronbach’s alpha coefficients for the CES-D in the present study were computed to be .69.

Action Self-Efficacy Scale–Physical Exercise (ASES-PE)

The ASES was developed by Renner and Schwarzer (2005) to operationalize the concept of health action self-efficacy with four subscales, namely, Nutrition Self-Efficacy, Physical Exercise Self-Efficacy, Alcohol Reduction Self-Efficacy, and Smoking Cessation Self-Efficacy subscales. The two-item ASES-PE subscale was used in this study (e.g., “I can manage to carry out my exercise intentions, even when I have worries and problems.”). ASES items are rated using a 4-point Likert-type rating scale ranging from 1 (very uncertain) to 4 (very certain). The internal consistency reliability coefficient (Cronbach’s alpha) for the PE scale was reported to be .79 by Renner and Schwarzer and .87 for the present study.

Outcome Expectancy Scale–Physical Exercise (OES-PE)

The OES was developed by Renner and Schwarzer (2005) to operationalize the concept of health outcome expectancies. It is composed of 12 items and four subscales (i.e., Nutrition, Physical Exercise, Alcohol Reduction, and Smoking Cessation Outcome Expectancy subscales.). The OES-PE scale was used in this study (e.g., “If I exercise regularly, my cholesterol level and blood pressure will improve.”). OES items are rated using a 4-point Likert-type rating scale ranging from 1 (not at all true) to 4 (exactly true). The internal consistency reliability coefficient (Cronbach’s alpha) for the PE scale was reported to be .81 by Renner and Schwarzer and .83 for the present study.

Health/Safety Risk Perceptions Scale (HRPS)

The HRPS was developed by Weber, Blais, and Betz (2002) to operationalize the likelihood that people would engage in risky and harmful health behaviors, along with the perception of the magnitude of the risks related to these risky health activities. The HRPS is composed of six items (e.g., “not exercising regularly [e.g., walking briskly for 30 min at least 3 times a week]).” HRPS items are rated on a 5-point Likert-type scale ranging from 1 (not at all risky) to 5 (extremely risky). The total score can range from 6 to 30. The internal consistency reliability coefficient (Cronbach’s alpha) for the HRPS was reported to be .81 by Weber et al. (2002) and .69 for the present study.

Health/Safety Expected Benefits Scale (HEBS)

The HEBS was developed by Weber et al. (2002) to operationalize the perception of the benefits of engaging in positive health activities. It is composed of six items (e.g., “exercising regularly [e.g., walking briskly for 30 min at least 3 times a week]”). HEBS items are rated on a 5-point Likert-type scale ranging from 1 (no benefits at all) to 5 (great benefits). The total score ranges from 6 to 30. The internal consistency reliability coefficient (Cronbach’s alpha) for HEBS was reported to be .82 by Weber et al. and .50 for the present study.

Barriers to Health Promoting Activities for Disabled Persons Scale (BHADP)

The BHADP was developed by Becker, Stuifbergen, and Sands (1991) to measure perceptions of barriers to health promotion activities. It is composed of 18 items and three subscales: (a) Intrapersonal Barriers (e.g., “too tired”), (b) Interpersonal (e.g., “other responsibilities”), and (c) Environmental Barriers (e.g., “lack of transportation”). Items are rated using a 4-point Likert-type scale ranging from 1 (never) to 4 (routinely). The total score ranges from 18 to 72. A high score means greater perceived barriers. The internal consistency reliability coefficient (Cronbach’s alpha) for BHADP was reported to be .82 by Becker et al. (1991) and.85 for the present study.

Maintenance Self-Efficacy Scale–Physical Exercise (MSES-PE)

The MSES-PE was developed by Luszczynska and Sutton (2006) to assess people’s perception of their maintenance self-efficacy to exercise regularly. It is composed of four items (e.g., “I am confident that I am able to do physical exercises regularly, even if exercising takes me a lot time”). Items are rated on a 4-point Likert-type scale ranging from 1 (not at all true) to 4 (exactly true). The total score can range from 4 to 16. The internal consistency reliability coefficient (Cronbach’s alpha) for MSES-PE was reported to be .81 by Luszczynska and Sutton and .92 for the present study.

Action Planning and Coping Planning Scale–Physical Exercise (APCPS-PE)

The APCPS-PE was developed by Sniehotta, Schwarzer, Scholz, and Schuz (2005) to measure the metacognition of action planning and coping planning for exercise. It is composed of 9 items and two subscales: (a) Action Planning subscale, five items (e.g., “I already have concrete plans for when to exercise”) and (b) Coping Planning, four items (e.g., “I already have concrete plans what to do if something intervenes”). Items are rated on a 4-point Likert-type scale from 1 (not at all true) to 4 (exactly true). The total score for the Action Planning subscale can range from 5 to 20, and the total score for the Coping Planning subscale can range from 4 to 16. Sniehotta et al. (2005) reported that the internal consistency reliability coefficients (Cronbach’s alpha) for action planning and coping planning were 0.92 and 0.90, respectively, and the reliability coefficients are .91 and .97 for the present study.

Recovery Self-Efficacy Scale–Physical Exercise (RSES-PE)

The RSES-PE was developed by Luszczynska and Sutton (2006) to operationalize the concept of recovery self-efficacy for regular exercise. It is composed of three items (e.g., “I am sure I can be physically active again regularly, even if I had failed to pull myself together to exercise”). Items are rated on a 4-point Likert-type scale ranging from 1 (not at all true) to 4 (exactly true). The total score ranges from 3 to 12. The internal consistency reliability coefficient (Cronbach’s alpha) for the RSES-E was reported by Luszczynska and Sutton to be .85 and it was .94 for the present study.

Medical Outcomes Study (MOS) Short-Form Health Survey (SF-12v2)

The SF-12v2 was developed by Ware, Kosinski, and Keller (1996) to operationalize the concept of health-related quality of life. It is composed of 12 items and eight subscales: (a) Physical Functioning, 2 items (e.g., “moderate activities, such as moving a table, pushing a vacuum cleaner, bowling, or playing golf”); (b) Role Limitations Due to Physical Problems, 2 items (e.g., “accomplished less than you would like”); (c) Bodily Pain, 1 item (“during the past 4 weeks, how much did pain interfere with your normal work [including both work outside the home and housework]?”); (d) General Health, 1 item (“in general, would you say your health is excellent/ very good/good/fair/poor?”); (e) Vitality, 1 item (“did you have a lot of energy?”); (f) Social Functioning, 1 item (“during the past 4 weeks, how much of the time has your physical health or emotional problems interfered with your social activities [like visiting with friends, relatives, etc.]?”); (g) Role Limitations Due to Emotional Problems, 2 items (e.g., “during the past 4 weeks, how much of the time have you had any of the following problems with your work or other regular daily activities as a result of any emotional problems [such as feeling depressed or anxious]?”); and (h) Mental Health, 2 items (e.g., “have you felt calm and peaceful?”). Nine items are rated on either a 5-point Likert-type scale from 1 (excellent) to 5 (poor); others used a 3-point Likert-type scale from 1 (yes, limited a lot) to 3 (no, not limited at all). The 12 items are summed as a Physical Component Summary Scale (PCS), a Mental Component Summary Scale (MCS), and a total score. The scores are standardized on a general population sample (M = 50, SD = 10). Test–retest reliability over a 2-week interval was reported to be .89 for the PCS and .76 for the MCS. The internal consistency reliability coefficient (Cronbach’s alpha) for the PCS and the MCS was computed to be .87 and .82, respectively, in the present study.

Satisfaction With Life Scale (SWLS)

The SWLS was developed by Diener, Emmons, Larsen, and Griffin (1985) to operationalize the concept of subjective well-being. It is composed of five items (e.g., “In most ways, my life is close to my ideal”). The items are rated on a 7-point Likert-type scale ranging from 1 (strongly disagree) to 7 (strongly agree). The total score can range from 5 to 35, with higher scores indicating greater life satisfaction. Test–retest reliability estimated over a 2-month interval was reported by Diener et al. (1985) to be .82. The internal consistency reliability coefficient (Cronbach’s alpha) was .92 for the present study.

Physical Activity Stages of Change Instrument (PASC)

The PASC was developed by Nigg et al. (2005) to operationalize the concept of readiness to engage in physical activity. In the present study, the PASC was used as an outcome measure to assess the degree of engagement in physical activity. The PASC is composed of four items (e.g., “Do you currently engage in regular physical activity?”). Items are rated on a dichotomous “Yes” or “No” format. A scoring algorithm was provided by Nigg et al. to convert the scores in the four items to represent the degree of engagement in physical activity along a 5-point continuum: 1 = precontemplation (PC), 2 = contemplation (C), 3 = preparation (P), 4 = action (A), and 5 = maintenance (M). Individuals with score of 1 are classified as preintenders; scores of 2 and 3 are considered intenders; and scores of 4 and 5 are considered actors for the purpose of this study.

Procedure

The NMSS was contacted to elicit their support for this research project. Participants were recruited from several state chapters of the NMSS, through a survey link on the “Researchers Need You” section of the NMSS website. Additional participants were recruited from a neurology clinic at a university teaching hospital in the Midwest. Participants who volunteered to participate in the project were given a link to complete the research packet developed by the first author on the surveymonkey.com website. Participants also received a US$10 gift card as a token of appreciation for participating in the study.

Data Analysis

Multiple discriminant analysis (MDA) was used to determine the ability of the HAPA motivation and volition indicators to discriminate among participants representing the three levels of stages of change to engage in exercise/physical activity in this study. The direct method was used to enter the discriminating variables into the discriminant function. Because of a limited sample size, the minimum error rate (shrinkage) of the discriminant analysis classification results was estimated by the jackknife procedure (Lachenbrach & Mickey, 1968). The Predictive Analytics SoftWare (PASW 18.0) package was used to perform the computations.

Results

Descriptive Statistics

Based on PASC scores, 47 participants (22%) were found to belong to the preintender group, 66 participants (31%) belong to the intender group, and 102 participants (47%) belong to the actor group. The means and standard deviations of MS severity (incapacity and social impairment), HAPA motivational and volitional factors, and health-related quality of life measures in T-scores for each stage of change groups are presented in Table 2.

Table 2.

Means and Standard Deviations of Severity, Motivational, Volitional, and Quality-of-Life Measures by Stages of Change Physical Activity Groups

	Stages of change groups
	Preintender	Intender	Actor
HAPA variable	M (SD)	M (SD)	M (SD)
Severity
Incapacity	53.68 (10.44)	51.48 (9.65)	47.35 (9.35)
Social impairment	53.19 (9.32)	51.51 (9.79)	47.56 (9.92)
Depression	49.15 (10.51)	53.00 (10.59)	48.46 (8.99)
Motivational constructs
Self-efficacy (motivational)	45.39 (9.95)	46.64 (8.77)	54.30 (9.02)
Risk perception	43.54 (10.84)	50.14 (9.71)	52.89 (8.36)
Outcome expectancies	42.57 (11.71)	50.40 (8.73)	53.17 (8.03)
Perceived barriers	54.81 (10.09)	54.51 (9.72)	45.05 (7.48)
Volitional constructs
Action planning	42.37 (10.36)	47.03 (8.80)	55.44 (7.10)
Coping planning	44.55 (9.35)	46.35 (9.01)	54.87 (8.57)
Self-efficacy (maintenance)	43.49 (9.62)	48.15 (9.09)	54.20 (8.76)
Self-efficacy (recovery)	43.54 (10.83)	47.63 (8.79)	54.51 (8.07)
Quality of life
Health-related quality of life	46.60 (8.36)	47.41 (10.15)	53.25 (9.66)
Life satisfaction	48.67 (9.34)	46.97 (9.55)	52.58 (9.99)

Note: HAPA = health action process approach.

Variables are converted to the T-score metric for ease of visual comparison. As can be observed, participants in the preintender groups had the highest average scores on incapacity (M = 53.68, SD = 10.44) and social impairment (M = 53.19, SD = 9.32), and the actor group had the lowest average scores on incapacity (M = 47.35, SD = 9.35) and social impairment (M = 47.56, SD = 9.92). The intender group had scores similar to the preintender group in terms of incapacity (M = 51.48, SD = 9.65) and social impairment (M = 51.51, SD = 9.79); intenders also had the highest average depression score (M = 53.00, SD = 10.59) compared with preintenders (M = 49.15, SD = 10.51) and actors (M = 48.46, SD = 8.99).

For the motivational constructs, the actor group had the highest action self-efficacy (M = 54.30, SD = 9.02) compared with the preintender (M = 45.39, SD = 9.95) and intender (M = 46.64, SD = 8.77) groups. Both intenders and actors had similarly high outcome expectancies (M = 50.40, SD = 8.73; M = 53.17, SD = 8.03) and risk perceptions scores (M = 50.14, SD = 9.71 ; M = 52.89, SD = 8.36) compared with the preintenders (M = 43.54, SD = 10.84). Both preintenders and intenders had higher perceived barrier scores (M = 54.81, SD = 10.09; M = 54.51, SD = 9.72) than participants in the actor group (M = 45.05, SD = 7.48).

For the volition constructs, participants in the actor group had the highest action and coping planning and maintenance and recovery self-efficacy scores, followed by the participants in the intender group and then by the preintender group. However, participants in the intender group had the lowest scores on social support (M = 47.66, SD = 10.05) compared with the preintender and the actor groups (M = 50.78, SD = 11.30; M = 51.15, SD = 9.14). Finally, participants in the actor group had the highest health-related quality of life and life satisfaction scores compared with participants in the preintender and intender groups; quality of life scores for preintenders and intenders were quite similar.

MDA

MDA was used to determine whether preintenders, intenders, and actors could be differentiated based on their motivational and volitional score patterns. The main reason for using MDA in this study is to identify factors or attributes that are able to separate or distinguish the predefined groups (Klecka, 1980). Specifically, a series of linear combination of attributes (i.e., canonical discriminant functions) contributing maximally to group separation is identified and substantively interpreted to provide meanings for the group differentiation. There is no definitive rule of thumb for computing the sample size for MDA. A conservative recommendation is to have 5 to 10 times as many observations for each discriminating variable per group. To meet this criterion, we combined the action, maintenance, and recovery self-efficacy variables as the exercise self-efficacy variable, and the action planning and coping planning variables as the planned behavior variable. Specifically, severity of MS, exercise self-efficacy, outcome expectancies, risk awareness, perceived barriers, and planned behavior were used as the discriminating variables, and the stages of change for exercise/physical activity variable were used as the group membership (dependent) variable.

Two significant discriminant functions were calculated. For the combination of both discriminant functions (1 through 2), the Wilks’s Lambda was computed to be .55, χ²(12, N = 215) = 124.91, p < .001. After the first function is removed, the test of Function 2 is still significant, Wilks’s Lambda = .92, χ²(5, N = 215) = 16.97, p < .01. The effect sizes for the discriminant functions are (.64)² = .41 and (.28)² = .08, respectively. The two functions accounted for about 41% and 8% of the total relationships between predictors and groups. The first discriminant function accounted for 89% of the between-group (explained) variance in the solution, whereas the second discriminant function accounted for 11% of the variance.

To interpret the meanings of the discriminant functions, the structure matrix (correlations between the two canonical discriminant functions and the discriminating HAPA variables) was rotated by the varimax method. The rotated structure matrix was examined to help define the discriminant functions. The correlations between the discriminating variables and the first significant canonical discriminant function were highest for (a) Planned Behavior (.79), (b) Exercise/Physical Activity Self-Efficacy (.70), and (c) Perceived Barriers (−.70). Based on the simple structure concept used in factor analysis, severity of MS (−.34) could also be a variable that is loaded on Function 1. Basically, the function represents less severity of disability, lower perceived barriers for exercise/physical activity, higher self-efficacy for exercise/physical activity, and higher action planning and coping planning ability for exercise/physical activity and can be characterized as represented by volitional factors with severity and perceived barriers as moderating variables. In Function 2, two motivational factors outcome expectancies (.76) and risk awareness (.61) were highly related to this function. The group centroids (group means) along the significant discriminant functions (the distance of each group from the center of the canonical function) indicated that the actor group was located at the positive end of the continuum on Function 1-Volition (0.83) and in the middle of the continuum on Function 2-Motivation (−0.07). The intender group was located at the positive end of the continuum on Function 2-Motivation (0.39) and in the middle of the continuum on Function 1-Volition (−0.53). The preintender group was located on the negative extreme of the continuum of both Function 2-Motivation (−0.39) and Function 1-Volition (−1.07). The results indicated that the HAPA motivational and volitional variables can maximally separate the preintender, intender, and action groups, with the preintender group maximally separated from the rest of the two groups based on low centroid scores on both motivational and volitional functions, the intender group was separated from the rest of the two groups based on high centroid score on the motivational function and moderate centroid score on the volitional function, and the actor group was separated from the other two groups based on high centroid score on the volitional function and moderate centroid score on the motivational function.

Classification functions for each stage of change group were then generated from the discriminant functions. The classification functions permit the input of an individual’s raw score for each of the HAPA variables to estimate the probability of the membership in each of the stage of change groups. Each individual’s subtest scores were entered as a separate classification function for each of the intender group levels. The individual was predicted to belong to the group for which the highest probability estimate was obtained. Overall, 68% of the participants were accurately classified, which is a significant improvement over the base rate (chance) prediction of 47% (i.e., the sample size [n = 102] of the largest group divided by the total sample [N = 215] and multiplied by 100). A classification function accuracy of 87% was achieved for the actor group, 51% for the preintender group, and 52% for the intender group, indicating that the discriminant functions are better at predicting the membership of the actor group than the preintender and intender groups. Finally, the jackknife procedure was used to assess the external validity of statistical results of discriminant analysis. The overall classification accuracy was reduced from 68% to 63%. The shrinkage (minimum error rate) of only 5% in accuracy suggested the MDA results can be replicated in other samples.

Discussion

Being healthy is an important condition for functioning optimally and integrating fully into all aspects of the American society, including work and independent living (Lynch & Chiu, 2009; Ravesloot,Seekins, & White, 2005). People with disabilities including people with MS are vulnerable to secondary conditions affecting their ability to obtain and retain employment. Health promotion interventions should be included as part of the standard services provided by state vocational rehabilitation agencies (Ipsen et al., 2010). However, there is a dearth of theory-driven, empirically validated health promotion for people with chronic illnesses and disabilities. The purpose of this study was to determine whether motivational and volitional variables identified in the HAPA model can be used to successfully differentiate people with MS in different stages of change for exercise and physical activity (Schwarzer et al., 2011). Schwarzer et al. (2011) suggest that people can be classified into preintender, intender, and actor groups based on their readiness for engagement in health-promoting behaviors. The HAPA intervention model hypothesizes that different sets of social-cognitive and behavioral variables will be important for different stages of change groups.

In the current study, the actor group was found to have the lowest severity of disability scores, whereas the preintender and intender groups shared similarly high severity scores. The results suggested that functional limitations and social impairments can prevent people with MS from engaging in health-promoting behavior such as exercise and physical activity. Therefore, physical therapy, occupational therapy, and rehabilitation psychology interventions to improve physical and social functioning may be an important requisite step to help increase the motivation of people with MS to exercise/physical activity. In terms of motivation, participants in the actor group perceived themselves as having high action self-efficacy, outcome expectancies, and risk awareness and low barriers for exercise/physical activity. Individuals in the intender group also indicated high outcome expectancies and risk awareness but low on action self-efficacy and high on perceived barriers for exercise/physical activity. The preintender group was low on action self-efficacy, outcome expectancies, and risk awareness and high on perceived barriers. According to the HAPA intervention matrix, only members of the preintender group are considered in need of interventions in motivational variables. However, it appears that the intender group will still need interventions to strengthen their self-efficacy beliefs and to reduce their perceived barriers for exercise/physical activity in order to move to the volition stage. In terms of volition, the actor group did have the highest scores on action and coping planning and maintenance and recovery self-efficacy, and the intender group also had higher scores than the preintender group on these volition variables. The results support the need to strengthen performance in volition variables to help people in the intender group to move to the actor group. For the actor group, it is important to focus on preventing individuals from relapsing to physical inactivity, and the enhancement of maintenance and recover self-efficacy will be important for people in the actor group. In terms of quality of life, individuals with MS who are engaging in exercise/physical activity behavior fare better and have higher health-related quality of life and life satisfaction than people in both the preintender and internder groups. Apparently, having intention but no action does not improve health-related quality of life and life satisfaction.

Importantly, MDA results indicated that HAPA motivational and volition variables can significantly differentiate the preintender, intender, and action groups consistent with the expectations of the HAPA intervention matrix, providing strong empirical evidence to support the usefulness of the HAPA framework for conceptualizing behavioral interventions for people with MS in different stages of readiness to promote engagement in exercise/physical activity and other health-promoting behaviors. Our research findings underscore the importance of social-cognitive variables in enhancing motivation to engage in health-promoting behavior and the importance of planned behavior (i.e., action and coping planning) in bridging the gaps between intention and action. The HAPA model can be used as a research framework to develop cognitive and behavioral measures and evidence-based interventions to promote exercise/physical activity and other health-promoting behaviors of people with MS using randomized clinical trials.

Limitations

There are several limitations that should be considered when applying or interpreting the results of this study. First, a convenience sample was used for this study, and the participants completed the research instruments through an online survey. It is possible to have sampling bias because people who have access and skills in using the Internet may constitute a unique group of individuals with MS. Moreover, individuals who know how to use community resources are more likely to join the local chapter of the NMSS; therefore, they may be different from people who are less aware of community resources. Second, the numbers of items for a variable was considered for the length of survey. To save participant time and energy, the study used several 2- to 3-item short forms, which may cause measurement problems. Third, all of the measures used in this study were self-report, which may not correspond to objective indicators. Finally, the HAPA model was more successful in predicting the action group and less successful in predicting the precontemplation and contemplation groups suggesting there may be additional factors (e.g., social support, health promotion resources, protection motivation, and empowerment) that may need to be included in the motivational and volitional phases of the HAPA model.

Implications for Rehabilitation Counseling Practice

The importance of preventing and managing secondary conditions to improve community participation and quality of life of people with disabilities including individuals with MS has been underscored by rehabilitation and health researchers. Being healthy is critical to the ability of people with MS to fully participate in the community including independent living and competitive employment. Rehabilitation counselors, with their training in medical aspects of disabilities and psychosocial interventions for people with disabilities, are uniquely qualified to conduct theory-driven research, develop and validate health promotion interventions, and deliver efficacious and effective health promotion services for people with disabilities within the state-federal vocational rehabilitation program. One of the most well-known health promotion programs developed specifically for people with disabilities is the Living Well With a Disability health promotion program. It is a consumer-directed, goal-focused health promotion program that helps individuals to develop foundations for lifestyle change. Ravesloot, Seekins, and Young (1998) evaluated the effectiveness of the Living Well program with 35 people with disabilities. The result showed that participants in the treatment group decreased 37% in reported limitations due to secondary conditions. Similarly, Ravesloot et al. (2005) investigated the effectiveness of a similar health promotion intervention for adults with mobility impairments. They recruited 188 participants and used an interrupted time series, staggered baseline, quasi-experimental design with random assignment to treatment start date. They found reductions in limitations from secondary conditions, symptom days, and health care utilization over the intervention period. Effects on secondary conditions lasted for 12 months. In addition, overall cost savings of US$807 per person (total for sample US$151,716) were projected from reductions in health care utilization of the study sample. Similarly, Zemper et al. (2003) tested the efficacy of a holistic wellness program for 43 adults with spinal cord injuries. The intervention program included physical activity, nutrition, lifestyle management, and prevention of secondary conditions. When they compared the within-group baseline with the final results, they found that the intervention group had fewer and less severe secondary conditions, and had significant improvement of health-related self-efficacy and health behaviors.

Although initial validation of several behavioral health promotion intervention programs for people with disabilities appear to be promising, it is important to note that the manner by which people with disabilities including people with MS manage their physical and mental health depends more on what they do themselves than on what is done to or for them. However, learning and practicing adaptive physical activity self-management techniques can be challenging, and the behavior changes necessary for physical activity self-management are unlikely to occur in the absence of significant motivation. Interventions such as the Living Well program provides a foundation for developing evidence-based interventions, and the HAPA framework allows us to improve and refine our physical activity self-management training for people with MS. It appears that the use of the HAPA framework and a motivational interviewing format to encourage the development of self-initiated health behaviors (e.g., physical activity, stress management, healthy diet, and social activity) and personal responsibility and commitment to a healthy lifestyle may be effective for people with MS. It is also important to incorporate low-impact activity training such as swimming, walking, aerobic, and alternative training such as yoga, tai chi, and qigong to strengthen action self-efficacy beliefs in health promotion interventions for people with MS. The HAPA framework provides the blueprint for developing the contents of a motivational based health promotion intervention program for people with MS. Efficacy of such HAPA-based motivational intervention can be validated using randomized controlled trials.

In conclusion, the phase approach used by the HAPA model to increase motivation and exercise/physical activity self-efficacy to engage in physical activity and other health-promoting behavior can potentially augment health promotion interventions already developed for people with disabilities. The empirical support for using the HAPA framework to promote exercise/physical activity behavior can probably generalize to other health-promoting behaviors such as diet, stress reduction, smoke cessation, and drinking in moderation.

Using the HAPA model, rehabilitation counselors could help individuals with disabilities to engage in health-promoting behavior such as exercise and physical activity. Increasing physical activity could lead to positive emotional responses to adversity and stress caused by disabilities or chronic illnesses. The ultimate goal of health promotion interventions, within the rehabilitation counseling field, is to help individuals to develop motivation and learn skills that are needed for the behavioral change. The HAPA framework provides with the necessary tools to identify the specific stages where the individual mind-set is in his or her continuum of behavioral change, from those who are contemplating about change to those who are already engaged in the target behavior. The advantage of this approach is that by knowing where the person is at in the behavior change continuum, rehabilitation counselors can develop stage-matched interventions tailored to facilitate the transition from one stage to the next one.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The contents of this article were developed with support through the Rehabilitation Research and Training Center on Effective Vocational Rehabilitation Service Delivery Practices established at both the University of Wisconsin–Madison and the University of Wisconsin–Stout under a grant from the Department of Education, National Institute on Disability and Rehabilitation Research (NIDRR) Grant No. PR# H133B100034. However, those contents do not necessarily represent the policy of the U.S. Department of Education, and endorsement by the Federal Government should not be assumed.

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