Applying an extended model of the theory of planned behaviour to breast self-examination

Few studies have examined the predictors of breast self-examination in younger women, where it is the primary method for the early detection of breast cancer. Female college students (N = 253, aged 17 to 50 years) completed items related to breast self-examination assessing theory of planned behaviour (TPB) constructs (intentions, attitude, subjective norm, perceived behavioural control), social influence variables of self-identity and group norm, and demographic characteristics. One month later, breast self-examination behaviour was assessed. Results supported this application of the TPB model and highlight the importance of group norms for strategies to increase breast self-examination in younger women.     

Using an extended theory of planned behaviour to inform interventions aimed at increasing breastfeeding uptake in primiparas experiencing material deprivation

Objectives The theory of planned behaviour (TPB) was employed to investigate infant feeding intentions and subsequent behaviour in women from selected areas of economic hardship in the UK. Underlying beliefs were examined in order to inform future interventions aimed at increasing breastfeeding uptake among women living in such areas, which is associated with low rates of breastfeeding. Design Midwives recruited women from areas meeting study criteria. TPB measures were obtained from 303 primiparas via postal questionnaires completed during pregnancy, and feeding method was subsequently obtained from 286 of these women. Results A model containing age, education, deprivation, attitude, subjective norm (SN), and perceived behavioural control (PBC) predicted intention to breastfeed (R²=.44) and intention to formula feed (R²=.45). A model controlling for age, education and deprivation predicted ever having breastfed (86.1% correctly classified) and ever having formula fed (77.1% correctly classified). MANCOVAs differentiated those who intended to breastfeed and subsequently did (inclined actors), those who intended to breastfeed but did not (inclined abstainers), and those who did not intend to breastfeed and did not (disinclined abstainers). Differentiating outcome beliefs, normative beliefs, and control beliefs are presented. Conclusions The TPB provided a useful framework with which to examine the factors underlying breastfeeding intentions and behaviour amongst primiparas. A grouping system based on the congruence between intentions and subsequent behaviour revealed important differences between beliefs of the three groups. Further research might usefully test the effectiveness of interventions targeting the beliefs identified here in increasing breastfeeding uptake and duration.     

The theory of planned behaviour in a randomized trial of a decision aid on cardiovascular risk prevention

Objective

To assess the feasibility and outcome of measuring the theory of planned behaviour (TPB) in patients receiving routine counselling versus counselling with a decision aid (DA) during primary care consultation on cardiovascular risk prevention.

Methods

A DA was developed, based on models of shared decision-making (SDM) and the TPB. We evaluated the impact of the intervention in a randomized controlled trial. Main outcomes were previously reported. To assess the intermediate social cognitive processes and our theoretical framework, we evaluated the impact of the intervention on a TPB scale.

Results

The TPB scale showed satisfactory measurement properties. Factor analysis (main component analysis, confirmatory model) could mostly replicate the assumptions of the model. 44% of variance of the behavioural intention to adhere to the decision after counselling was explained in linear regression models. Of the TPB components, only attitude towards the decision and moral norm were significantly more positive in the intervention. No difference was found with regard to intention to adhere to the decision. High risk resulted in higher values of the TPB components in both groups.

Conclusion

Most DAs are developed and tested without explicitly referring to a theoretical model of psychosocial processes. The TPB may serve as a useful theoretical framework.

Practice Implications

Trials on DAs demonstrate positive effects on psychological outcomes of patients without leading to better objective health results. Our study might contribute to an explanation: DAs might not cause stronger adherence to decisions even though one's attitude towards the decision becomes more positive.     

With a little help from my goals: Integrating intergoal facilitation with the theory of planned behaviour to predict physical activity

Objective . Integration of a multiple goal theory approach into the theory of planned behaviour (TPB) to investigate how the perceived facilitating and conflicting relationships in multiple goal pursuit predict performance of a health‐related behaviour. Design . Prospective design with 8‐week follow‐up. Methods . At baseline, perceived intergoal facilitation and intergoal conflict were measured using personal projects analysis supplemented with standard TPB measures for physical activity (PA). Self‐reported PA was measured at follow‐up 8 weeks later. N=137 participants completed measures at both time points (55.4% response rate at follow‐up). Results . Hierarchical regression showed that perceived intergoal facilitation, but not intergoal conflict, directly predicted PA beyond intention and perceived behavioural control (PBC), accounting for more than 4% of additional variance in PA. Intergoal facilitation had an indirect effect on intention through attitude and PBC, and intention partially mediated the effect of intergoal facilitation on behaviour. Conclusion . The perceived facilitating effect of pursuing other personal goals predicts the performance of a health‐related behaviour over and above single behaviour‐focused social cognitions.     

Evidence that theory of planned behaviour variables mediate the effects of socio-demographic variables on homeless people's participation in service programmes

This article reports findings from two studies (N = 88, N = 100) using Ajzen's theory of planned behaviour (TPB) to predict homeless people's uptake of service programmes. Study 1 was conducted with an opportunity sample whereas Study 2 employed a representative sample. Both studies provide support for the application of the TPB, and demonstrate that the effects of demographic characteristics on behaviour were mediated by TPB variables. The discussion focuses on the role of attitudinal and normative components in actual behaviour, and on the potential role of social normative processes and stigmatization in homeless people's uptake of services.     

Use of mental simulations to change theory of planned behaviour variables

Objectives The predictive validity of the theory of planned behaviour is well established, but much less is known about: (a) whether there are causal relationships between key components of the model and (b) how to go about changing the theory of planned behaviour variables. This study tested the ability of outcome and process simulations to change variables specified in the theory of planned behaviour in relation to blood donation. Design Participants (N = 146) were randomized to one of four conditions: outcome simulation only, process simulation only, process‐plus‐outcome simulation and a distractor control condition. The dependent variables were state anxiety, and intention attitude, subjective norm and perceived control from the theory of planned behaviour. Methods Participants were asked to empty their mind and visualize themselves: (a) after donating blood (outcome manipulation), (b) preparing to donate blood (process manipulation), (c) both preparing to donate blood and after having donated blood (process‐plus‐outcome manipulation) or (d) both preparing to get a high mark and after having got a high mark on their course (control condition). Following mental rehearsal, participants completed the dependent variables. Results There were no main effects of outcome simulation, but process simulation successfully increased intention, subjective norm and perceived control. There was also a significant outcome simulation × process simulation interaction for attitude. The effect of the process manipulation on intention was mediated by subjective norm and perceived control. Conclusions The findings show promise for the use of mental simulations in changing cognitions and further research is required to extend the present findings to other health behaviours.     

The theory of planned behaviour predicts self‐reports of walking,but does not predict step count

Objectives. This paper compares multiple measures of walking in two studies, and the second study compares how well Theory of Planned Behaviour (TPB) constructs perform in predicting these different measures. Methods. In Study 1, 41 participants wore a New Lifestyles NL‐2000 pedometer for 1 week. Subsequently, participants completed a questionnaire containing measures of the TPB constructs and two self‐report measures of walking, followed by two interview measures of walking. For Study 2, 200 RAF trainee aircraftsmen wore pedometers for 2 weeks. At the end of each week, participants completed the questionnaire and interview measures of walking. Results. Both studies found no significant association between questionnaire measures of walking and pedometer measures. In Study 1, the interview measures produced significant, large correlations with the pedometer measure, but these relationships were markedly weaker in the second study. TPB variables were found to explain 22% of variance in intention to walk in Study 1 and 45% of the variance in Study 2. In Study 2, prediction of subsequent measures of behaviour was found to be weak, except when using a single‐item measure of walking. Conclusions. Recall of walking is poor, and accurate measurement by self‐report is problematic. Although the TPB predicts intentions to walk well, it does not predict actual amount of walking, as assessed by pedometer. Possible reasons for these findings include the unique nature of walking as an activity primarily used to facilitate higher order goals. The use of single‐item measures may exaggerate the effectiveness of the TPB model for walking, and possibly other forms of physical activity.     

Testing an integrated model of the theory of planned behaviour and self‐determination theory for different energy balance‐related behaviours and intervention intensities

Objectives The aim of the study was to test the relations between constructs from the self‐determination theory (autonomous and controlled motivation), the theory of planned behaviour (attitudes, self‐efficacy, and intentions), and behaviour change within a theoretically integrated model. Additionally, the aim was to test if these relations vary by behaviour (physical activity or dietary behaviour) or intervention intensity (frequency). Design. It was a randomized controlled trial with a ‘usual care’ condition (medical screening only) and an intervention condition (medical screening+access to a website and coaching). Participants in the latter condition could freely determine their own intervention intensity. Methods. Participants (N= 287) completed measures of the theoretical constructs and behaviour at baseline and after the first intervention year (N= 236). Partial least squares path modelling was used. Results. Changes in autonomous motivation positively predicted changes in self‐efficacy and intentions towards a healthy diet. Changes in controlled motivation positively predicted changes in attitudes towards physical activity, changes in self‐efficacy, and changes in behavioural intentions. The intervention intensity moderated the effect of self‐efficacy on intentions towards physical activity and the relationship between attitude and physical activity. Changes in physical activity were positively predicted by changes in intentions whereas desired changes in fat intake were negatively predicted by the intervention intensity. Conclusions Important relations within the theoretically integrated model were confirmed but others were not. Moderation effects were found for behaviour and intervention intensity.     

Comparing solutions to the expectancy‐value muddle in the theory of planned behaviour

Objectives The authors of the Theories of Reasoned Action (TRA) and Planned Behaviour (TPB) recommended a method for statistically analysing the relationship between the indirect belief‐based measures and the direct measures of attitude, subjective norm, and perceived behavioural control (PBC). However, there is a growing awareness that this yields statistically uninterpretable results. This study's objective was to compare two solutions to what has been called the ‘expectancy‐value muddle’. These solutions were (i) optimal scoring of modal beliefs and (ii) individual beliefs without multiplicative composites. Design Cross‐sectional data were collected by telephone interview. Methods Participants were 110 first‐degree relatives (FDRs) of patients diagnosed with colorectal cancer (CRC), who were offered CRC screening in the study hospital (83% response rate). Participants were asked to rate the TPB constructs in relation to attending for CRC screening. Results There was no significant difference in the correlation between behavioural beliefs and attitude for rescaled modal and individual beliefs. This was also the case for control beliefs and PBC. By contrast, there was a large correlation between rescaled modal normative beliefs and subjective norm, whereas individual normative beliefs did not correlate with subjective norm. Conclusions Using individual beliefs without multiplicative composites allows for a fairly unproblematic interpretation of the relationship between the indirect and direct TPB constructs ( French & Hankins, 2003 ). Therefore, it is recommended that future studies consider using individual measures of behavioural and control beliefs without multiplicative composites and examine a different way of measuring individual normative beliefs without multiplicative composites to that used in this study.     

Using past behaviour and spontaneous implementation intentions to enhance the utility of the theory of planned behaviour in predicting exercise

Objectives. This study examined the utility of the theory of planned behaviour (TPB), past behaviour, and spontaneous implementation intentions in predicting exercise behaviour. The psychological correlates of spontaneous implementation intentions and the moderating effects of intention, perceived behavioural control, past behaviour, and implementation intentions at various time points were also examined. Design. Data collection occurred over three phases with a 2‐ and 3‐week interval. The attrition rate was 35.97% leaving a total of 162 participants (63 males, 99 females). In the first wave, participants completed measures of TPB, spontaneous implementation intentions, and past behaviour. Behaviour was assessed in the second and third waves, and a follow‐up measure of spontaneous implementation intentions was completed in Phase 3. Results. Several regression analyses were conducted. Attitude towards exercise and perceived behavioural control made a significant contribution to the prediction of intention. Intention made a significant contribution to the prediction of implementation intentions. Spontaneous implementation intentions reduced the effect of intention and past behaviour for behaviour at 2 weeks and when indexed over a 5‐week period. When behaviour was measured for a 3‐week period (following an initial 2‐week period), the variance that intention and past behaviour accounted for in exercise behaviour decreased, and spontaneous implementation intentions were no longer a significant predictor of behaviour. Spontaneous implementation intentions were found to interact with past behaviour, such that implementation intentions predicted exercise behaviour only among participants who did not exercise frequently in the past. Conclusions. Implications and future research directions are discussed.     

Integrating the theory of planned behaviour and self‐determination theory in health behaviour: A meta‐analysis

Purpose A meta‐analysis of studies integrating the theory of planned behaviour (TPB) and self‐determination theory (SDT) in health contexts is presented. The analysis aimed to provide cumulative empirical support for a motivational sequence in which self‐determined motivation from SDT predicts the proximal predictors of intentions and behaviour from the TPB. Methods A literature search identified 36 integrated studies providing 45 tests of effects between TPB and SDT variables. Hunter and Schmidt's (1994) methods of meta‐analysis were used to correct the effect sizes across the studies for statistical artifacts. Age (old versus young), publication status (published versus unpublished), study design (correlational versus experimental/intervention), and behaviour type (physical activity versus other health‐related behaviours) were evaluated as moderators of the effects. A path‐analysis using the meta‐analytically derived correlations was conducted to examine the proposed motivational sequence. Results Statistically significant corrected correlations were evident among the perceived autonomy support and self‐determined motivation constructs from SDT and the attitude, subjective norms, perceived behavioural control, intention, and health‐related behaviour constructs from the TPB. Only six of the 28 effect sizes were moderated by the proposed moderators. Path analysis revealed that the significant effects of self‐determined motivation on intentions and behaviour were partially mediated by the proximal predictors from the TPB. Conclusions Evidence from this synthesis supported the theoretical integration and proposed motivational sequence. Results are discussed with reference to the complementary aspects of the TPB and SDT and the need for integrated experimental or intervention studies on a broader range of health behaviours.     

Using the theory of planned behaviour to understand binge drinking: the importance of beliefs for developing interventions

Objectives. To elicit students’ salient beliefs in relation to binge drinking, and to examine the extent to which individual salient beliefs predict theory of planned behaviour (TPB) constructs in relation to binge drink, and actual drinking behaviour assessed later that evening. Design. Longitudinal, over a single evening. Methods. 192 students were recruited as they entered a campus bar at the beginning of the evening. They completed questionnaires with open‐ended questions eliciting beliefs concerning binge drinking, and ratings scales assessing standard TPB constructs in relation to binge drinking. At the end of the evening, 181 completed a second questionnaire and recorded the number of alcoholic drinks they had consumed. Results. Beliefs were reliably coded (all kappas ≥0.79). Students with higher intentions to binge drink were more likely to believe that their friends approved of binge drinking, and that (lack of) money would make it difficult. Students who reported drinking more alcohol at the end of the evening were more likely to believe that getting drunk is an advantage/what they would like about binge drinking tonight, that their sports teams would approve, and that celebrating, drinking patterns, and environment would make it easy to binge drink. Conclusions. The present study has identified the individually salient beliefs relating to drinking behaviour that the TPB states should be addressed by interventions to alter behaviour, and which that should be assessed as mediators in intervention research. As a whole, these findings highlight the importance of perceived peer norms in binge drinking in this population, and support the idea of interventions to challenge the perception of social pressure to binge drink.     

Childhood behaviour, psychotic symptoms and psychosis onset in young people at high risk of schizophrenia: early findings from the edinburgh high risk study

BACKGROUND: Several studies suggest that many patients with schizophrenia have pre-morbid neurodevelopmental abnormalities. This study examines how behavioural abnormalities are associated with mild psychotic symptoms and later schizophrenic illness. METHODS: Maternal ratings on the Child Behavior Checklist (CBCL) of the early behaviour of 155 subjects were obtained at entry to the Edinburgh study of people at high risk of schizophrenia. These maternal ratings were compared in those with and without psychotic symptoms and used to predict the later onset of psychosis. RESULTS: The CBCL syndrome scores for the children prior to age 13 did not distinguish any of the study groups at entry to the study. In the ratings made for the subjects when aged from 13 to 16, delinquent behaviour and 'other problems' were weakly associated with these symptoms. However, with the exception of somatic symptoms and thought problems, the age 13-16 scales were significant predictors of later schizophrenic illness. This was true also for some of the ratings prior to age 13. CONCLUSIONS: Various behaviours, in particular, withdrawn and delinquent-aggressive behaviour in adolescents at risk of schizophrenia may predict later onset of the illness. These behaviours, however, are far less predictive of isolated psychotic symptoms prior to psychosis onset.     

Autonomy and control: augmenting the validity of the theory of planned behaviour in predicting exercise

This study examined the utility of the theory of planned behaviour (TPB) along with additional constructs in predicting exercise, and explored the motivational antecedents of exercise intentions. Participants included 162 Canadian University College students (61% females). Measures of TPB, autonomous and controlling intention, perceived autonomy support and core autonomous intention were completed during phase 1 of data collection. Two and three weeks later behaviour was assessed. Hierarchical regression analyses revealed that: (a) attitude and perceived behavioural control significantly predicted TPB intention and core autonomous intention; (b) subjective norm predicted controlling intention; and (c) perceived autonomy support predicted autonomous and core autonomous intention. TPB intention significantly predicted behaviour. TPB is a fairly useful model for predicting behaviour and important information can be gained when other measures of intention are explored.