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

An evolutionary perspective on health psychology: new approaches and applications

Although health psychologists' efforts to understand and promote health are most effective when guided by theory, health psychology has not taken full advantage of theoretical insights provided by evolutionary psychology. Here, we argue that evolutionary perspectives can fruitfully inform strategies for addressing some of the challenges facing health psychologists. Evolutionary psychology's emphasis on modular, functionally specialized psychological systems can inform approaches to understanding the myriad behaviors grouped under the umbrella of "health," as can theoretical perspectives used by evolutionary anthropologists, biologists, and psychologists (e.g., Life History Theory). We detail some early investigations into evolutionary health psychology, and we provide suggestions for directions for future research.

Attitudes and beliefs regarding depression, HIV/AIDS, and HIV risk-related sexual behaviors among clinically depressed African American adolescent females

Individuals' attitudes and beliefs toward behaviors are key indicators of behavioral performance. The purposes of this study were to elucidate attitudes and beliefs about depression, HIV/AIDS, and HIV risk-related sexual behaviors among clinically depressed African American adolescent females and to develop an understanding of their context for HIV risk. For this descriptive qualitative inquiry, semistructured interviews and surveys were employed (N = 24). The narratives reveal that behavioral sequelae of depression (i.e., loneliness) can produce risk for HIV. These findings may guide psychiatric nurse educators, scientists, and practitioners to modify HIV risk among clinically depressed African American adolescent females.

Identifying the psychological determinants of risky riding: an application of an extended Theory of Planned Behaviour

The Theory of Planned Behaviour (TPB) plus moral norms, anticipated regret, past behaviour, self-identity and perceived susceptibility was applied to predicting motorcyclists' intention to ride above the speed limit and ride at inappropriate speeds. Past behaviour, control beliefs, attitudes, moral norm, normative beliefs, age and self-identity explained 60% of the variance in motorcyclists' intention to exceed the speed limit on motorways (N=1381). A total of 62% of the variance in motorcyclists' intention to really go for it on rural roads was accounted for, with past behaviour, attitudes, control beliefs, age, normative beliefs, anticipated regret, self-identity, behavioural beliefs and training status being significant (N=1116). Finally, attitudes, past behaviour, control beliefs, moral norm, anticipated regret, behavioural beliefs, normative beliefs, engine size and self-identity explained 57% of the variance in motorcyclists' intention to ride faster than felt safe in order to keep up with the group (N=1940). The belief-based measures also successfully differentiated between those who intended to speed and those who did not. Theoretical and practical implications of the findings are discussed.

Does action planning moderate the intention-habit interaction in the exercise domain? A three-way interaction analysis investigation

Both habit strength and action planning have been found to moderate the intention-exercise behaviour relationship, but no research exists that has investigated how habit strength and action planning simultaneously influence this relationship. The present study was designed to explore this issue in a prospective sample of undergraduate students (N = 415): action planning, habit strength, intention, attitudes, subjective norms and perceived behavioural control were assessed at baseline and exercise behaviour was assessed 2 weeks later. Both habit strength and action planning moderated the intention-exercise relationship, with stronger relationship at higher levels of planning or habit strength. Decomposing a significant action planning × habit strength × intention interaction showed that the strength of the intention-exercise relationship progressed linearly through levels of action planning and habit strength. These novel results show that action planning strengthens the intention-habit strength interaction in the exercise domain: exercise interventions should therefore focus on simultaneously bolstering action planning and habit strength.

Can the theory of planned behaviour predict the physical activity behaviour of individuals?

The theory of planned behaviour (TPB) can identify cognitions that predict differences in behaviour between individuals. However, it is not clear whether the TPB can predict the behaviour of an individual person. This study employs a series of n-of-1 studies and time series analyses to examine the ability of the TPB to predict physical activity (PA) behaviours of six individuals. Six n-of-1 studies were conducted, in which TPB cognitions and up to three PA behaviours (walking, gym workout and a personally defined PA) were measured twice daily for six weeks. Walking was measured by pedometer step count, gym attendance by self-report with objective validation of gym entry and the personally defined PA behaviour by self-report. Intra-individual variability in TPB cognitions and PA behaviour was observed in all participants. The TPB showed variable predictive utility within individuals and across behaviours. The TPB predicted at least one PA behaviour for five participants but had no predictive utility for one participant. Thus, n-of-1 designs and time series analyses can be used to test theory in an individual.

Correlates of physical activity in a population-based sample of kidney cancer survivors: an application of the theory of planned behavior

Background

Over half of kidney cancer survivors (KCS) are completely inactive and only a quarter are meeting physical activity (PA) guidelines. This highlights the need to identify and understand the determinants of PA in this understudied population. The purpose of this study is to determine the social cognitive correlates of PA intention and behavior in KCS using the Theory of Planned Behavior (TPB).

Methods

All 1,985 KCS diagnosed between 1996 and 2010 in Alberta, Canada were mailed a self-report survey that consisted of the Godin Leisure Time Exercise Questionnaire and standard TPB items for intention, planning, perceived behavioral control (PBC), affective and instrumental attitudes, and descriptive and injunctive norms. Standard demographic and medical variables were also collected.

Results

Completed surveys were received from 703 of 1,654 (43%) eligible KCS. The TPB was tested using structural equation modelling and demonstrated an adequate-to-good fit to the data [χ² = 256.88, p < .001; TLI = 0.97; CFI = 0.98; RMSEA = 0.06, 90% CI = 0.05-0.06].

There were significant pathways to PA from PBC (ß = 0.18, p = 0.02), planning (ß = 0.22, p < 0.01), and intention (ß = 0.31, p < 0.01); and to planning from intention (ß = 0.81, p < 0.01). In addition, there were significant model pathways to intention from instrumental attitude (ß = 0.28, p = 0.03), descriptive norm (ß = 0.09, p = 0.01), and PBC (ß = 0.52, p < 0.01). Overall, the TPB accounted for 69%, 63%, and 42% of the variance in intention, planning and PA, respectively.

Conclusion

The TPB appears to be a useful model for explaining PA in KCS. All TPB constructs except injunctive norm and affective attitude were useful for explaining intention with PBC emerging as the largest correlate. Developing PA interventions based on the TPB may be effective in promoting PA in KCS and may lead to important improvements in health.

Understanding how adherence goals promote adherence behaviours: a repeated measure observational study with HIV seropositive patients

BACKGROUND

The extent to which patients follow treatments as prescribed is pivotal to treatment success. An exceptionally high level (> 95%) of HIV medication adherence is required to suppress viral replication and protect the immune system and a similarly high level (> 80%) of adherence has also been suggested in order to benefit from prescribed exercise programmes. However, in clinical practice, adherence to both often falls below the desirable level. This project aims to investigate a wide range of psychological and personality factors that may lead to adherence/non-adherence to medical treatment and exercise programmes.

METHODS

HIV positive patients who are referred to the physiotherapist-led 10-week exercise programme as part of the standard care are continuously recruited. Data on social cognitive variables (attitude, intention, subjective norms, self-efficacy, and outcome beliefs) about the goal and specific behaviours, selected personality factors, perceived quality of life, physical activity, self-reported adherence and physical assessment are collected at baseline, at the end of the exercise programme and again 3 months later. The project incorporates objective measures of both exercise (attendance log and improvement in physical measures such as improved fitness level, weight loss, improved circumferential anthropometric measures) and medication adherence (verified by non-invasive hair analysis).

DISCUSSION

The novelty of this project comes from two key aspects, complemented with objective information on exercise and medication adherence. The project assesses beliefs about both the underlying goal such as following prescribed treatment; and about the specific behaviours such as undertaking the exercise or taking the medication, using both implicit and explicit assessments of patients' beliefs and attitudes. We predict that i) the way people think about the underlying goal of their treatments explains medication and exercise behaviours over and above the effects of the behaviour-specific thinking and ii) the relationship between adherence to exercise and to medical treatment is stronger among those with more favourable views about the goal. Results from this study should identify the key contributing factors to inform subsequent adherence research and afford a more streamlined assessment matrix. The project also aims to inform patient care practices. UK CLINICAL RESEARCH NETWORK REGISTRATION NUMBER: UKCRN 7842.

Development of an intervention programme to encourage high school students to stay in school for lunch instead of eating at nearby fast-food restaurants

Many schools have recently adopted food policies and replaced unhealthy products by healthy foods. Consequently, adolescents are more likely to consume a healthy meal if they stay in school for lunch to eat a meal either prepared at home or purchased in school cafeterias. However, many continue to eat in nearby fast-food restaurants. The present paper describes the development of a theory-based intervention programme aimed at encouraging high school students to stay in school for lunch. Intervention Mapping and the Theory of Planned Behaviour served as theoretical frameworks to guide the development of a 12-week intervention programme of activities addressing intention, descriptive norm, perceived behavioural control and attitude. It was offered to students and their parents with several practical applications, such as structural environmental changes, and educational activities, such as audio and electronic messages, posters, cooking sessions, pamphlets, improvisation play theatre, quiz, and conferences. The programme considers theoretical and empirical data, taking into account specific beliefs and contexts of the target population. This paper should help programme planners in the development of appropriate interventions addressing the problem.

Self-determined forms of motivation predict sport injury prevention and rehabilitation intentions

OBJECTIVES

Two studies were conducted to examine how motivational regulations from self-determination theory (SDT) influenced athletes' intentions towards sport-injury rehabilitation (Study 1) and prevention behaviours (Study 2) using the theory of planned behaviour (TPB) as a framework.

DESIGN

A cross-sectional survey was employed.

METHODS

Elite athletes (Study 1: N=214; Study 2: N=533) completed the Treatment Self-Regulation Questionnaire and psychometric measures of constructs from the TPB, with respect to their rehabilitation from sport injury in a hypothetical scenario (Study 1), or their injury prevention experiences (Study 2).

RESULTS

Partial least squares path analytic models indicated acceptable fit of the hypothesised model in all samples, and consistently found in both studies that autonomous motivation from SDT was positively associated with attitudes, subjective norms and perceived behavioural control from the TPB, and these three TPB variables positively predicted intentions of injury rehabilitation and prevention. Controlled motivation from SDT was, unexpectedly, positively linked to intentions, but the effect was smaller than that for autonomous motivation.

CONCLUSIONS

Motivational regulations from SDT might serve as sources of information that influence athletes' intentions through their impact on the attitude, perceived social norm and controllability of injury rehabilitation and prevention.

An exploratory randomised controlled trial using short messaging service to facilitate insulin administration in young adults with type 1 diabetes

This exploratory randomised controlled trial examined the effectiveness of a novel short messaging service intervention underpinned by the theory of planned behaviour (TPB) in improving insulin administration in young adults with type 1 diabetes and the role of moderating variables. Those in the intervention condition (N = 8) received one daily text message underpinned by TPB constructs: Attitudes, subjective norms, perceived behavioural control and intention. Those in the control condition (N = 10) received weekly general health messages. Self-reported insulin administration was the main outcome measure; conscientiousness and consideration of future consequences (CFC) were measured as potential moderators. Analyses of covariance revealed no main effects of condition for morning and afternoon injections but a marginally significant effect for evening injections (p = .08). This main effect was qualified by significant interactions of condition with conscientiousness (p = .001), CFC (p = .007) and a three-way interaction among condition, conscientiousness and CFC (p = .009). Exploration of the interactions indicated the intervention significantly improved evening injection rates only in the low conscientiousness and low CFC groups. This effect was particularly strong among those low in both conscientiousness and CFC. Further investigation is warranted, using more objective measures of insulin adherence in a larger sample.

Exploring the question-behaviour effect: randomized controlled trial of motivational and question-behaviour interventions

PURPOSE

Measuring intentions and other cognitions to perform a behaviour can promote performance of that behaviour (the question-behaviour effect, QBE). It has been suggested that this effect may be amplified for individuals motivated to perform the behaviour. The present research tested the efficacy of combining a motivational intervention (providing personal risk information) with measuring intentions and other cognitions in a fully crossed 2 × 2 design with an objective measure of behaviour in an at-risk population using a randomized controlled trial (RCT).

METHODS

Participants with elevated serum cholesterol levels were randomized to one of four conditions: a combined group receiving both a motivational intervention (personalized cardiovascular disease risk information) and a QBE manipulation (completing a questionnaire about diet), one group receiving a motivational intervention, one group receiving a QBE intervention, or one group receiving neither. All participants subsequently had the opportunity to obtain a personalized health plan linked to reducing personal risk for coronary heart disease.

RESULTS

Neither the motivational nor the QBE manipulations alone significantly increased rates of obtaining the health plan. However, the interaction between conditions was significant. Decomposition of the interaction indicated that the combined condition (motivational plus QBE manipulation) produced significantly higher rates of obtaining the health plan (96.2%) compared to the other three groups combined (80.3%).

CONCLUSIONS

The findings provide insights into the mechanism underlying the QBE and suggest the importance of motivation to perform the behaviour in observing the effect.

STATEMENT OF CONTRIBUTION

What is already known on this subject? Research has indicated that merely asking questions about a behaviour may be sufficient to produce changes in that or related behaviours (referred to as the question-behaviour effect; QBE). Previous studies have suggested that the QBE may be moderated by the individual's motivation to change the behaviour, i.e., the QBE will only produce increases in the behaviour among those with strong motivation to perform the behaviour. However, no study has directly tested this prediction by manipulating motivation and examining impacts on the QBE. What does this study add? The present study tested the individual and combined effects of a motivational and a QBE intervention in a fully crossed design using a randomized controlled trial (RCT) and showed that: a combined intervention significantly increased behaviour. effect partially mediated by cognitions.

The effectiveness of a motivational interviewing primary-care based intervention on physical activity and predictors of change in a disadvantaged community

Little research exists on the impact of behavior change interventions in disadvantaged communities. We conducted a prospective study to explore the effectiveness of motivational interviewing on physical activity change within a deprived community and the social- psychological and motivational predictors of change in physical activity including stage of change, self-efficacy, social support, and variables from self-determination theory and the theory of planned behavior. Five motivational interviewing counsellors recruited 207 patients and offered motivational interviewing sessions to support physical activity behavior change. At 6-months there were significant improvements in physical activity, stage of change, and social support. A dose-response relationship was evident; those who attended 2 or more consultations increased their total physical activity, stage of change and family social support more than those who attended just one. Hierarchical regression analyses indicated that number of sessions and change in stage of change predicted 28.4% of the variance in change in total physical activity and, with social support from friends, 21.0% of the variance in change walking time. Change in perceived behavioral control and attitudes, friend social support, and number of sessions predicted 16.8% of the variance in change in vigorous physical activity. Motivational interviewing is an effective approach for promoting physical activity amongst lower socio-economic status groups in the short term. The study demonstrates good translational efficacy, and contributes to a limited number of physical activity interventions targeting low income groups in the UK.

Predicting university undergraduates' binge-drinking behavior: a comparative test of the one- and two-component theories of planned behavior

This study provides a comparative test of the one- and two-component theories of planned behavior (TPB) in the context of university undergraduates' binge-drinking. Participants (N=120) self-completed questionnaire measures of all TPB constructs at time 1 and subsequent binge-drinking at time 2 (two-weeks later). The data were analyzed using a combination of path analyses and bootstrapping procedures. Both models accounted for a substantial proportion of the variation in behavior. However, the two-component TPB provided a significantly better fit to the data, with the total direct and indirect effects accounting for 90% of the variance. Intention was the only direct predictor of behavior. Instrumental attitude, affective attitude and self-efficacy had indirect effects. Although health interventions could usefully target these cognitive antecedents, simulation analyses, modeling the effects of cognition change on behavior, showed that only large-sized (0.8 SD) changes to affective attitude, or moderate-sized changes to all of these cognitions in combination were sufficient to reduce binge-drinking.

An extended theory of planned behavior intervention for older adults with type 2 diabetes and cardiovascular disease

A randomized controlled trial evaluated the effectiveness of a 4-wk extended theory of planned behavior (TPB) intervention to promote regular physical activity and healthy eating among older adults diagnosed with Type 2 diabetes or cardiovascular disease (N = 183). Participants completed TPB measures of attitude, subjective norm, perceived behavioral control, and intention, as well as planning and behavior, at preintervention and 1 wk and 6 wk postintervention for each behavior. No significant time-by-condition effects emerged for healthy eating. For physical activity, significant time-by-condition effects were found for behavior, intention, planning, perceived behavioral control, and subjective norm. In particular, compared with control participants, the intervention group showed short-term improvements in physical activity and planning, with further analyses indicating that the effect of the intervention on behavior was mediated by planning. The results indicate that TPB-based interventions including planning strategies may encourage physical activity among older people with diabetes and cardiovascular disease.