PubMed Health⌕ Search

Biomedical subjects

Ryan E Rhodes

Publications and source records attributed to Ryan E Rhodes.

At least 19 recordsLinked to original sources
PubMed2007

Perception, attitudes and beliefs, and openness to change: implications for older driver education.

With a rapidly aging population, strategies for improving driver safety are beginning to emerge that focus on changing driving behaviors and knowledge. We examined the perceptions of risk, beliefs and attitudes, and openness to change of 86 older participants voluntarily attending a driver education program. It appeared that most people attending these sessions were not necessarily concerned about their own driving, safety or abilities, but were interested in maintaining mobility. They were conservative and reasonably consistent in their attitudes toward traffic regulations and safe driving practices. Some gender differences emerged with more men than women being resistant to changing their driving habits, more men than women reporting that they drive after consuming alcohol and more women than men identifying a role for their families in decision-making regarding driving cessation. This suggests that educational material may need to be targeted differently for men and women. It is anticipated that psychosocial factors related to driving such as driver perception, beliefs and openness to change will be useful for maximizing the fit between education program content and outcomes.

Age Factors↗
PubMed2006

Testing a conceptual model related to weight perceptions, physical activity and smoking in adolescents.

The purpose of this study was to test a conceptual model based on theoretical and empirically supported relationships related to the influences of weight perceptions, weight concerns, desires to change weight, friends, age and location in relation to physical activity (PA) and smoking in adolescents. A total of 1242 males and 1446 females (mean age = 15.6 +/- 1.3) were recruited from rural and urban Canadian schools. Study respondents provided self-reports of PA, 'smoking', 'perceived body weight', 'desire to change weight', 'concern about weight gain' and 'friends' smoking and PA behaviors'. Results revealed an acceptable fitting model chi2 (40) = 155.63, P < 0.05, root mean square error of approximation = 0.047 and comparative fit index = 0.98. Large effect sizes for both genders were observed between friends' and adolescents' smoking behavior, and between perceived body weight and desire to change weight. Further, significant differences were identified between the male and female models [chi2 difference (24) = 65.28, P < 0.05]. Several findings of this study point to the need to design programs to motivate adolescent females to adopt healthy weight-control practices and to target young peoples' social networks to promote health behaviors, especially with regard to smoking.

Adolescent↗
PubMed2006

Physical activity and Native Americans: a review.

The physical activity behaviors of Native-American populations in the United States and Canada have received little attention in the health literature. The purpose of this review was to unite the literature regarding the physical activity behaviors of Native Americans. A majority of the literature was obtained using online databases. Reference lists were also reviewed to gain further access to the literature. Key-word searches included various combinations of Aboriginal, Native Indian, American Indian, Native American, First Nation, Métis, or Alaska Native with physical activity, exercise, and health behavior. Articles included were those published in English-language, peer-reviewed journals from 1990 until November 2005 that focused on participants aged 18 years and older. This review is organized according to ecologic models of health behavior, which take into account several correlates to explain human behavior, including demographic, personal health, environmental, and psychosocial. Correlates were included if they appeared at least three times in the literature. As a result of these inclusion criteria, the number of reviewed articles includes 28 quantitative, 4 qualitative, and 3 intervention studies. Results indicate that age, gender, and social support are important factors associated with physical activity. The remaining correlates show inconsistent or indeterminate results due in part to the paucity of research. It is suggested that an increase in the number of studies, especially those using longitudinal designs, is needed. Further, the application of psychosocial models to understand physical activity motivations as well as culturally appropriate and validated measurement tools are largely absent in the Native-American physical activity literature.

Adult↗
PubMed2006

Predicting physical activity intention and behaviour among children in a longitudinal sample.

We examined predictors of leisure-time physical activity intention and behaviour in children, and the potential direct and moderating effects of gender and ethnicity. Participants were 364 (230 Asian; 134 Caucasian) 9-11-year-old children who completed measures of the theory of planned behaviour (TPB) and physical activity behaviour (Physical Activity Questionnaire for Children) across three, 3-month intervals (i.e., two prediction time-periods) in Canada. The TPB explained 35-50% of the variance in physical activity behaviour and 74-76% of the variance in intention using structural equation modelling. An autoregressive longitudinal path model showed that the TPB predicted changes in physical activity and physical activity predicted changes in TPB constructs (p<.05). Overall, intention and perceived behavioural control were significant (p<.05) contributors to the direct prediction of behaviour and subjective norm and perceived behavioural control were significant (p<.05) predictors of intention. Gender did not show a robust relationship with physical activity or intention, but the effect of ethnicity on physical activity was mediated through perceived behavioural control (Asians less active than Caucasians). Finally, gender and ethnicity did not moderate TPB and physical activity relations (p<.05). These data suggest that childhood may be a formative stage for the development of physical activity cognitions and that promoting physical activity in children may require normative and control-based intervention.

Asian People↗
PubMed2006

Relationships among dog ownership and leisure-time walking in Western Canadian adults.

BACKGROUND: Dog ownership may be an effective tailored intervention among adults for promoting physical activity. This study examined the relationship between walking, physical activity levels, and potential psychological mediators between people who owned dogs and those who did not own dogs in the Capital Region District of Greater Victoria, British Columbia, Canada. Data were collected in September 2004; analyses were conducted in January 2005. METHODS: A random sample of men (n=177) and women (n=174) aged 20 to 80 years participated. Questionnaires were mailed out in 2004 to collect information about demographics, dog ownership, leisure-time walking, physical activity levels, and theory of planned behavior (TPB) constructs. RESULTS: The analyses revealed that dog owners spent more time in mild and moderate physical activities and walked an average of 300 minutes per week compared to non-dog owners who walked an average of 168 minutes per week. A mediator analysis suggests that dog obligation acts as a mediator between dog ownership and physical activity. Moreover, the theory of planned behavior constructs of intention and perceived behavioral control explained 13% of the variance in walking behavior with an additional 11% variance in walking behavior being explained by dog obligation. Regarding intention to walk, the TPB explained 46% of the variance in intention to walk with dog obligation adding an additional 1% variance. CONCLUSIONS: In this group of Canadians, those who owned a dog participated in more mild to moderate physical activity than those who did not. Acquiring a dog should be explored as an intervention to get people more physically active.

Adult↗
PubMed2006

Understanding action control: predicting physical activity intention-behavior profiles across 6 months in a Canadian sample.

Intention is theorized as the proximal determinant of behavior in some theories of motivation, but the need to understand predictors of action control (i.e., translating an intention into behavior) is warranted to tailor physical activity intervention efforts. The purpose of this study was to examine constructs of the transtheoretical model of behavior change (TTM) as predictors of physical activity intention-behavior profiles across 6 months in a large Canadian sample (N = 1,192). Results showed that 5 of the 8 possible intention-behavior profiles had a substantial number of participants: nonintenders, unsuccessful adopters, successful adopters, unsuccessful maintainers, and successful maintainers. Constructs of the TTM distinguished (p < .01) intention-behavior profiles. Self-efficacy and the behavioral processes of change were particularly good predictors of action control (p < .01), but disaggregated beliefs and processes identified specific intervention targets for successful physical activity adoption and maintenance. The results validate that both action planning and action control are important when understanding physical activity behavior.

Adolescent↗
PubMed2006

The built-in environment: the role of personality and physical activity.

Personality trait psychology has seen a reemergence in recent years, and researchers are beginning to apply personality models to understand health behavior habits. This review features recent research on personality correlates of physical activity (PA) and the integration of personality with PA-related social cognition. The current definition and status of general personality work is introduced followed by a review and discussion of the evidence for personality and PA relations. The review concludes with recommendations for personality-matched PA marketing and experimental and longitudinal designs.

Biomarkers↗
PubMed2006

A multicomponent model of the theory of planned behaviour.

The purpose of this study was to investigate the measurement and predictive structure of multiple components of attitude (affective and instrumental), subjective norm (injunctive and descriptive) and an alternative measure of perceived behavioural control (PBC; skills/ability, opportunity, and resources) in the exercise domain. An additional purpose of the study was to compare the validity of the alternative PBC measure to a standard PBC measure for predicting exercise intention and behaviour. Participants were 220 undergraduates who completed measures of the theory of planned behaviour (TPB) and a 2-week follow-up of exercise behaviour. Results supported the discriminant validity in the measurement domains of all TPB components. Predictive validity of exercise behaviour for these components, however, was only evident for attitude and PBC components. Our alternative PBC measure was found commensurate with the standard PBC measure. Finally, intention significantly (p < .05) predicted exercise behaviour (R2 = .42), while affective attitude, and perceived opportunity significantly (p < .05) predicted intention (R2 = .47).

Adult↗
PubMed2006

Parental correlates of physical activity in children and early adolescents.

This article is intended to unite the existing research on parental influences on children's physical activity behaviours in order to establish direction for future research and improve existing child physical activity intervention programmes. A comprehensive, 34-study review of parental correlates of child physical activity was conducted and six variables were examined. There were significant correlations found between parental support and child physical activity level. Results for an association between parental and child physical activity levels, however, were mixed. There were not enough studies to draw conclusions about single-parent families, family socioeconomic status and ethnicity. Finally, there were some weak inter- and intra-generational sex correlations, but these results were mostly inconclusive. Possible mechanisms, including parental support, modelling, shared activities, societal differences by generation, minority groups and genetics are discussed, and recommendations are made on translating experimental results into tangible intervention efforts essential for disease prevention through increased physical activity.

Adolescent↗
PubMed2006

Conceptual categories or operational constructs? Evaluating higher order theory of planned behavior structures in the exercise domain.

The theory of planned behavior (TPB) is a popular framework for understanding the informational and motivational influences of exercise behavior One tenet of this model that has not been examined is the belief that direct measures of TPB component constructs are organized through higher order constructs. The authors'purpose of this article was to test this higher order conceptualization in comparison with a multidimensional TPB model using structural equation modeling. Participants (N=268) completed direct measures of the TPB and a 2-week follow-up of exercise behavior The results generally supported multidimensional TPB constructs over higher order structures. Direct measures of attitude (i.e., affective and instrumental) and subjective norm (i.e., injunctive and descriptive) had better psychometric properties when considered multidimensionally. Perceived behavioral control (i.e., self-efficacy, controllability), however, had estimation problems for both the multidimensional and the higher order model. Aggregation of TPB components is not warranted, and the perceived behavioral control components may possess a structure more complex than simple multidimensionality or a superordinate higher order construct.

Attitude↗
PubMed2005

Can current physical activity act as a reasonable proxy measure of future physical activity? Evaluating cross-sectional and passive prospective designs with the use of social cognition models.

BACKGROUND: The standard methodological approach for evaluating social cognitive theories when predicting physical activity behavior is the passive prospective/longitudinal survey design. Although this design is logical, a cross-sectional design may be a cost-effective alternative if the relationships between social cognitive constructs and physical activity are relatively stable. The purpose of this study was to evaluate the utility of a concurrent measure of physical activity used in a cross-sectional design in comparison to the standard prospective measure. METHODS: This study included two 6-month prediction time-periods, between 1997 and 1998, for the purpose of analysis replication, and the theory of planned behavior, the transtheoretical model, protection motivation theory, and social cognitive theory as the models of interest in a population sample (N = 703). RESULTS: Results showed trivial (69% of tests; q < 0.10) to small (31% of tests; q = 0.11-0.18) differences in the correlations between social cognitive constructs and vigorous physical activity occur when using a cross-sectional or prospective design. The cross-sectional design estimated slightly larger coefficients than the prospective design. CONCLUSIONS: It appears that a measure of concurrent physical activity included in a cross-sectional design can act as a reasonable proxy measure of future behavior measured in a passive prospective/longitudinal design. These findings support the use of cross-sectional designs when researchers seek a standard correlational investigation of physical activity and social cognitive constructs with the possibility that coefficients may be slightly biased upwards.

Adult↗
PubMed2004

Creating parsimony at the expense of precision? Conceptual and applied issues of aggregating belief-based constructs in physical activity research.

The aggregation of measured social cognitive beliefs to form scales is a common procedure in physical activity research. In this paper, we propose that specific beliefs may actually have unique associations with physical activity, which are obscured by the practice of aggregation. Further, we point out that beliefs may be related in a more complex manner than the theory behind scale aggregation. Both of these factors are interpreted in terms of limiting physical activity intervention efforts. Therefore, the purpose of this study was to examine alternatives to summative scales of physical activity beliefs using structural equation modeling. Demonstrations were performed using belief-based constructs of self-efficacy, pros and cons with a large Canadian random sample (N = 683) over three, 6-month time points. Results demonstrated that items of belief-based scales are multidimensional and that a correlated belief structure fit the observed data better (P < 0.05) and explained more variance in vigorous physical activity (an additional 6-7%) than aggregated scales. Finally, a causally ordered structure among beliefs was supported, suggesting that items within a scale may be linked causally rather than as indicators of a higher-order latent variable. Implications for future research and physical activity interventions are discussed.

Adolescent↗
PubMed2004

Exercise motivation and adherence in cancer survivors after participation in a randomized controlled trial: an attribution theory perspective.

The purpose of this study was to examine postprogram exercise motivation and adherence in cancer survivors who participated in the Group Psychotherapy and Home-Based Physical Exercise (GROUP-HOPE; Courneya, Friedenreich, Sela, Quinney, & Rhodes, 2002) trial. At the completion of the GROUP-HOPE trial, 46 of 51 (90%) participants in the exercise group completed measures of attribution theory constructs. A 5-week follow-up self-report of exercise was then completed by 30 (65%) participants. Correlational analyses indicated that program exercise, perceived success, expected success, and affective reactions were strong predictors of postprogram exercise. In multivariate stepwise regression analyses, program exercise and perceived success were the strongest predictors of postprogram exercise. Additionally, perceived success was more important than objective success in understanding the attribution process, and it interacted with personal control to influence expected success and negative affect. Finally, postprogram quality of life and changes in physical fitness were correlates of perceived success. We concluded that attribution theory may have utility for understanding postprogram exercise motivation and adherence in cancer survivors.

Adult↗
PubMed2004

Promoting exercise behaviour: an integration of persuasion theories and the theory of planned behaviour.

OBJECTIVES: The purpose of this study was to examine the effectiveness of a theoretical integrated persuasive message on exercise motivation in college students. METHOD: Four hundred and fifty introductory psychology students (M age = 20.02 years; SD = 3.94) were randomly assigned to reading positively or negatively framed strong messages advocating exercise. The messages were attributed to a credible source, a non-credible source or to a no-source control condition. Theory of planned behaviour (TPB) constructs (i.e. attitude, subjective norm, perceived behavioural control) and cognitive responses (i.e. thought listing) were measured immediately and 2 weeks following the delivery of the intervention. RESULTS: Unfortunately, the results did not corroborate previous research, as we did not find any significant effects between experimental groups on any psychological or behavioural variable. CONCLUSIONS: There may be several potential explanations for the lack of effects, including the interaction between the type of persuasive information (TPB implications) and sources of persuasion and how these persuasive messages are processed (elaboration likelihood model/cognitive response implications). The theoretical implications of this research are discussed with a view towards future directions for exercise promotion initiatives using theoretically driven interventions.

Adult↗
PubMed2003

The group psychotherapy and home-based physical exercise (group-hope) trial in cancer survivors: physical fitness and quality of life outcomes.

Physical exercise has been shown to enhance quality of life (QOL) in cancer survivors using pretest-posttest designs and compared to usual care (i.e. no intervention). In the present study, we conducted a randomized controlled trial to determine if exercise could improve QOL in cancer survivors beyond the known benefits of group psychotherapy (GP). We matched 22 GP classes (N=108) on content and then randomly assigned 11 (n=48) to GP alone and 11 (n=60) to GP plus home-based, moderate-intensity exercise (GP+EX). Participants completed a physical fitness test and QOL measures (e.g. Functional Assessment of Cancer Therapy scales) at the beginning and end of GP classes (about 10 weeks). We had excellent recruitment (81%), retention (89%), and adherence (84%) rates and a modest contamination (22%) rate. Using intention-to-treat repeated measures analyses of variance, we found significant Time by Condition interactions for functional well-being, fatigue, and sum of skinfolds. We also found borderline significant interactions for physical well-being, satisfaction with life, and flexibility. All interactions favored the GP+EX condition. We conclude that a home-based, moderate intensity exercise program may im-prove QOL in cancer survivors beyond the benefits of GP, particularly in relation to physical and functional well-being.

Adult↗
PubMed2003

Investigating multiple components of attitude, subjective norm, and perceived control: an examination of the theory of planned behaviour in the exercise domain.

The presence of two subcomponents within each theory of planned behaviour (TPB) concept of attitude (affective and instrumental), subjective norm (injunctive and descriptive), and PBC (self-efficacy and controllability) has been widely supported. However, research has not examined whether the commonality of variance between these components (i.e. a general factor) or the specificity of variance within the subcomponents influences intention and behaviour. Therefore, the purpose of this study was to examine the optimal conceptualization of either two subcomponents or a general common factor for each TPB concept within an omnibus model. Further, to test whether conceptualizations may differ by population even within the same behavioural domain, we examined these research questions with 300 undergraduates (M age = 20) and 272 cancer survivors (M age = 61) for exercise behaviour. Results identified that a general subjective norm factor was an optimal predictive conceptualization over two separate injunctive and descriptive norm components. In contrast, a specific self-efficacy component, and not controllability or a general factor of PBC, predicted intention optimally for both samples. Finally, optimal models of attitude differed between the populations, with a general factor best predicting intention for undergraduates but only affective attitude influencing intention for cancer survivors. The findings of these studies underscore the possibility for optimal tailored interventions based on population and behaviour. Finally, a discussion of the theoretical ambiguity of the PBC concept led to suggestions for future research and possible re-conceptualization.

Adolescent↗
PubMed2003

Relationships between personality, an extended theory of planned behaviour model and exercise behaviour.

OBJECTIVES: The purpose of this study was to investigate the theory of planned behaviour's (TPB) mediating hypothesis between the five-factor model of personality and exercise behaviour using an extended TPB model including concepts of affective and instrumental attitude, injunctive and descriptive norm, controllability, and selfefficacy. It was hypothesized that extraversion's activity facet would have a significant direct effect on exercise behaviour while controlling for the TPB, based on the presupposition that activity may represent a disposition that predicts exercise beyond planned behaviour. DESIGN: To test the replicability of these findings, we examined this research question with undergraduate students prospectively and cancer survivors, using a cross-sectional design. RESULTS: Using structural equation modelling, the results indicated that activity had a significant effect (p <.05) on exercise behaviour (study 1 =.20; study 2 =.31) while controlling for the TPB. CONCLUSIONS: This study suggests the importance of extraversion's activity facet on exercise behaviour, even when controlling for a TPB model with additional socialcognitive concepts and disparate population samples.

Adult↗