Kyra Hamilton

Bio: Kyra Hamilton is an academic researcher from Griffith University. The author has contributed to research in topics: Theory of planned behavior & Medicine. The author has an hindex of 42, co-authored 191 publications receiving 5224 citations. Previous affiliations of Kyra Hamilton include Queensland University of Technology & University of Western Australia.

A randomised controlled trial of a theory-based intervention to improve sun protective behaviour in adolescents ('you can still be HOT in the shade'): study protocol

Abstract: Background Most skin cancers are preventable by encouraging consistent use of sun protective behaviour. In Australia, adolescents have high levels of knowledge and awareness of the risks of skin cancer but exhibit significantly lower sun protection behaviours than adults. There is limited research aimed at understanding why people do or do not engage in sun protective behaviour, and an associated absence of theory-based interventions to improve sun safe behaviour. This paper presents the study protocol for a school-based intervention which aims to improve the sun safe behaviour of adolescents.

Fewer emergency readmissions and better quality of life for older adults at risk of hospital readmission: a randomized controlled trial to determine the effectiveness of a 24-week exercise and telephone follow-up program.

Abstract: Objective: To evaluate the effectiveness of an exercise-based model of hospital and in-home follow-up care for older people at risk of hospital readmission on emergency health service utilization and quality of life. Design: Randomised controlled trial Setting: Tertiary metropolitan hospital, Australia Participants: 128 patients (64 intervention, 64 control) with an acute medical admission, aged >65 years and with at least one risk factor for readmission (multiple comorbidities, impaired functionality, aged >75 years, recent multiple admissions, poor social support, history of depression). Intervention: Comprehensive nursing and physiotherapy assessment and individually tailored program including exercise strategies and nurse conducted home visit and telephone follow-up; commencing in hospital and continuing following discharge for 24 weeks. Outcome measures: Emergency health service utilization (emergency hospital readmissions and visits to Emergency Department, General Practitioner, or allied health professional) and health related quality of life (SF12v2) collected at baseline and 4, 12 and 24 weeks following discharge. Results: The intervention group required significantly less emergency hospital readmissions (22% of intervention group, 47% of control group, P=0•007); and emergency GP visits (25% of intervention group, 67% of control group, P<0•001). The intervention group also reported significantly greater improvements in quality of life in comparison to the control group as measured with SF12v2 Physical Component summary scores (F(3,279)=30•43, P<0•001) and Mental Component Summary scores (F(3,279)=7•20, P<0•001). Conclusions: Early introduction of a tailored exercise program and long term telephone follow-up may reduce emergency health service utilization and improve quality of life of older adults at risk of hospital readmission.

Extending the theory of planned behavior: the role of self and social influences in predicting adolescent regular moderate-to-vigorous physical activity.

Abstract: The current study aimed to test the validity of an extended theory of planned behavior model (TPB; Ajzen, 1991), incorporating additional self and social influences, for predicting adolescent moderate-to-vigorous physical activity. Participants (N = 423) completed an initial questionnaire that assessed the standard TPB constructs of attitude, subjective norm, and perceived behavioral control, as well as past behavior, self-identity, and the additional social influence variables of group norms, family social support, friends’ social support, and social provisions. One week after completion of the main questionnaire, participants completed a follow-up questionnaire that assessed self-reported physical activity during the previous week. The standard TPB variables—past behavior, self-identity, and group norms, but not social support infuences—predicted intentions, with intention, past behavior, and self-identity predicting behavior. Overall, the results provide support for an extended version of the TPB incor...

Extending the Theory of Planned Behavior: The Role of Self and Social Influences in Predicting Adolescent Regular Moderate-to-Vigorous Physical Activity

Abstract: The current study aimed to test the validity of an extended theory of planned behavior model (TPB; Ajzen, 1991), incorporating additional self and social influences, for predicting adolescent moderate-to-vigorous physical activity. Par ticipants (N = 423) completed an initial questionnaire that assessed the standard TPB constructs of attitude, subjective norm, and perceived behavioral control, as well as past behavior, self-identity, and the additional social influence variables of group norms, family social support, friends’ social support, and social provisions. One week after completion of the main questionnaire, participants completed a follow-up questionnaire that assessed self-reported physical activity during the previous week. The standard TPB variables—past behavior, self-identity, and group norms, but not social support influences—predicted intentions, with intention, past behavior, and self-identity predicting behavior. Overall, the results provide support for an extended version of the TPB incorporating self-identity and those social influences linked explicitly to membership of a behaviorally relevant reference group.

Prospective prediction of health-related behaviours with the Theory of Planned Behaviour: a meta-analysis

Abstract: This meta-analysis explored the efficacy of the Theory of Planned Behaviour (TPB) dependent on behaviour and methodological moderators. A lack of hierarchical analysis in previous reviews risks confounding these moderators. Here moderating roles of behaviour type, length of follow-up, sample age and behavioural measure are explored hierarchically amongst prospective tests of the TPB, controlling for past behaviour where possible. Searching identified 237 prospective tests from 206 articles. Random-effects meta-analytic procedures were used to correcting correlations for sampling and measurement error. Behaviour type moderated the model; physical activity and diet behaviours were better predicted (23.9% and 21.2% variance explained, respectively) whilst risk, detection, safer sex and abstinence from drugs were poorly predicted (between 13.8 and 15.3% variance explained). Methodological moderators were also apparent: age of sample moderated relations with student samples better predicted for physical activi...

Wnt signaling in cancer.

Abstract: Wnt signaling is one of the key cascades regulating development and stemness, and has also been tightly associated with cancer. The role of Wnt signaling in carcinogenesis has most prominently been described for colorectal cancer, but aberrant Wnt signaling is observed in many more cancer entities. Here, we review current insights into novel components of Wnt pathways and describe their impact on cancer development. Furthermore, we highlight expanding functions of Wnt signaling for both solid and liquid tumors. We also describe current findings how Wnt signaling affects maintenance of cancer stem cells, metastasis and immune control. Finally, we provide an overview of current strategies to antagonize Wnt signaling in cancer and challenges that are associated with such approaches.