Impact of a physical activity intervention program on cognitive predictors of behaviour among adults at risk of Type 2 diabetes (ProActive randomised controlled trial)

Making Specific Plan Improves Physical Activity and Healthy Eating for Community-Dwelling Patients With Chronic Conditions: A Systematic Review and Meta-Analysis

Background

Implementation intention formed by making a specific action plan has been proved effective in improving physical activity (PA) and dietary behavior (DB) for the general, healthy population, but there has been no meta-analysis of their effectiveness for patients with chronic conditions. This research aims to analyze several explanatory factors and overall effect of implementation intention on behavioral and health-related outcomes among community-dwelling patients.

Methods

We searched CIHNAL (EBSCO), PUBMED, Web of Science, Science Direct, SAGE Online, Springer Link, Taylor & Francis, Scopus, Wiley Online Library, CNKI, and five other databases for eligible studies. Random-effects meta-analysis was conducted to estimate effect sizes of implementation intention on outcomes, including PA, DB, weight, and body mass index. And the eligible studies were assessed by the Cochrane Collaboration's tool for risk of bias assessment. Sensitivity analysis adopted sequential algorithm and the p-curve analysis method.

Results

A total of 54 studies were identified. Significant small effect sizes of the intervention were found for PA [standard mean difference (SMD) 0.24, 95% confidence interval (CI) (0.10, 0.39)] and for the DB outcome [SMD -0.25, 95% CI (-0.34, -0.15)]. In moderation analysis, the intervention was more effective in improving PA for men (p < 0.001), older adults (p = 0.006), and obese/overweight patients with complications (p = 0.048) and when the intervention was delivered by a healthcare provider (p = 0.01).

Conclusion

Implementation intentions are effective in improving PA and DB for community dwelling patients with chronic conditions. The review provides evidence to support the future application of implementation intention intervention. Besides, the findings from this review offer different directions to enhance the effectiveness of this brief and potential intervention in improving patients' PA and DB.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=160491.

From cars to bikes - The effect of an intervention providing access to different bike types: A randomized controlled trial

Introduction

We aimed to investigate whether providing parents with children in kindergarten with access to different bicycle types could influence (i) travel behavior and cycling amount, and (ii) intrinsic motivation for cycling and psychological constructs related to car use.

Methods

A randomized, controlled trial was conducted in Southern Norway from September 2017 to June 2018. In total 36 parents were recruited and randomly drawn into an intervention (n = 18) or control group (n = 18). The intervention group was in random order equipped with an e-bike with trailer (n = 6), a cargo (longtail) bike (n = 6) and a traditional bike with trailer (n = 6).

Results

At follow-up, more participants from the intervention group (vs. the control group) were classified as cyclists to the workplace (n = 7 (38.9%) vs. n = 1 (5.9%), p = 0.04), but not to the kindergarten (n = 6 (33.3%) vs. n = 2 (11.8%), p = 0.23) or to the grocery store (n = 2 (11.1%) vs. n = 0 (0%), p = 0.49). A significant (p = ≤0.05) increase in cycling frequency (0.1 to 2.0 days/week) from baseline to follow-up was found in the intervention group for all destinations and seasons, except to the grocery store during winter (p = 0.16). A decrease in frequency of car driving (-0.2 to -1.7 days/week) was found to be apparent in terms of travelling to the workplace and the kindergarten for all seasons, yet not to the grocery store for any season (p = 0.15–0.49). The intervention group (vs. the control group) reported significantly higher “intrinsic regulation” for cycling (p = 0.01) at follow-up.

Conclusion

Access to different bike types for parents with children attending kindergarten resulted in overall increased cycling, decreased car use and higher intrinsic motivation for cycling. E-bikes obtained the greatest cycling amount in total, with the smallest sample variability. Hence, providing parents with children in kindergarten with access to e-bikes might result in increased and sustained cycling, also during the winter season.

Interventions for prevention of type 2 diabetes in relatives: A systematic review

The relatives and partners of people with type 2 diabetes are at increased risk of developing type 2 diabetes. This systematic review examines randomized controlled trials, written in English that tested an intervention, which aimed to modify behaviors known to delay or prevent type 2 diabetes, among the relatives or partners of people with type 2 diabetes. Study quality was assessed using the Cochrane Collaboration's tool for assessing risk of bias. Seven studies met the inclusion criteria. The majority of studies were at low risk of bias. Six studies tested an intervention in first-degree relatives of people with type 2 diabetes and one in partners. Intervention components and intervention intensity across studies varied, with those targeting diet and physical activity reporting the most significant changes in primary outcomes. Only one study did not observe significant changes in primary outcomes. There were three main recruitment approaches: advertising in the community, recruiting people through their relatives with diabetes, or identifying people as high risk by screening of their own health care contacts. Some evidence was found for potentially successful interventions to prevent type 2 diabetes among the relatives and partners of people with type 2 diabetes, although finding simple and effective methods to identify and recruit them remains a challenge. Future studies should explore the effect of patients' perceptions on their family members' behavior and capitalize on family relationships in order to increase intervention effectiveness.

Effective techniques for changing physical activity and healthy eating intentions and behaviour: A systematic review and meta-analysis

PURPOSE

The primary aim of this study was to review the evidence on the impact of a change in intention on behaviour and to identify (1) behaviour change techniques (BCTs) associated with changes in intention and (2) whether the same BCTs are also associated with changes in behaviour.

METHODS

A systematic review was conducted to identify interventions that produced a significant change in intention and assessed the impact of this change on behaviour at a subsequent time point. Each intervention was coded using a taxonomy of BCTs targeting healthy eating and physical activity. A series of meta-regression analyses were conducted to identify effective BCTs.

RESULTS

In total, 25 reports were included. Interventions had a medium-to-large effect on intentions (d₊  = 0.64) and a small-to-medium effect (d₊  = 0.41) on behaviour. One BCT, 'provide information on the consequences of behaviour in general', was significantly associated with a positive change in intention. One BCT, 'relapse prevention/coping planning', was associated with a negative change in intention. No BCTs were found to have significant positive effects on behaviour. However, one BCT, 'provide feedback on performance', was found to have a significant negative effect. BCTs aligned with social cognitive theory were found to have significantly greater positive effects on intention (d₊  = 0.83 vs. 0.56, p < .05), but not behaviour (d₊  = 0.35 vs. 0.23, ns), than those aligned with the theory of planned behaviour.

CONCLUSIONS

Although the included studies support the notion that a change in intention is associated with a change in behaviour, this review failed to produce evidence on how to facilitate behaviour change through a change in intention. Larger meta-analyses incorporating interventions targeting a broader range of behaviours may be warranted. Statement of contribution What is already known on this subject? Prior research on the causal relationship between intention and behaviour has produced mixed findings. Further experimental research to determine the precise nature of these variables is clearly warranted. However, precise guidance on how to change intention is still lacking. What does this study add? This study aimed to identify behaviour change techniques associated with changes in intention and behaviour. Techniques with positive effects on intention were identified; however, these did not have an impact on behaviour. Larger meta-analyses incorporating interventions targeting a broader range of behaviours may be warranted.

A randomised controlled trial of three very brief interventions for physical activity in primary care

Background

Very brief interventions (VBIs) for physical activity are promising, but there is uncertainty about their potential effectiveness and cost. We assessed potential efficacy, feasibility, acceptability, and cost of three VBIs in primary care, in order to select the most promising intervention for evaluation in a subsequent large-scale RCT.

Methods

Three hundred and ninety four adults aged 40–74 years were randomised to a Motivational (n = 83), Pedometer (n = 74), or Combined (n = 80) intervention, delivered immediately after a preventative health check in primary care, or control (Health Check only; n = 157). Potential efficacy was measured as the probability of a positive difference between an intervention arm and the control arm in mean physical activity, measured by accelerometry at 4 weeks.

Results

For the primary outcome the estimated effect sizes (95 % CI) relative to the Control arm for the Motivational, Pedometer and Combined arms were respectively: +20.3 (−45.0, +85.7), +23.5 (−51.3, +98.3), and −3.1 (−69.3, +63.1) counts per minute. There was a73% probability of a positive effect on physical activity for each of the Motivational and Pedometer VBIs relative to control, but only 46 % for the Combined VBI. Only the Pedometer VBI was deliverable within 5 min. All VBIs were acceptable and low cost.

Conclusions

Based on the four criteria, the Pedometer VBI was selected for evaluation in a large-scale trial.

Trial registration

Current Controlled Trials ISRCTN02863077. Retrospectively registered 05/10/2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3684-7) contains supplementary material, which is available to authorized users.

A theory-based process evaluation alongside a randomised controlled trial of printed educational messages to increase primary care physicians' prescription of thiazide diuretics for hypertension [ISRCTN72772651]

BACKGROUND

Pragmatic trials of implementation interventions focus on evaluating whether an intervention changes professional behaviour under real-world conditions rather than investigating the mechanism through which change occurs. Theory-based process evaluations conducted alongside pragmatic randomised trials address this by assessing whether the intervention changes theoretical constructs proposed to mediate change. The Ontario Printed Educational Materials (PEM) cluster trial was designed to increase family physicians' guideline-recommended prescription of thiazide diuretics. The trial found no intervention effect. Using the theory of planned behaviour (TPB), we hypothesised that changes in thiazide prescribing would be reflected in changes in intention, consistent with changes in attitude and subjective norm, with no change to their perceived behavioural control (PBC), and tested this alongside the RCT.

METHODS

We developed and sent TPB postal questionnaires to a random sub-sample of family physicians in each trial arm 2 months before and 6 months after dissemination of the PEMs. We used analysis of covariance to test for group differences using a 2 × 3 factorial design. We content-analysed an open-ended question about perceived barriers to thiazide prescription. Using control group data, we tested whether baseline measures of TPB constructs predicted self-reported thiazide prescribing at follow-up.

RESULTS

Four hundred twenty-six physicians completed pre- and post-intervention questionnaires. Baseline scores on measures of TPB constructs were high: intention mean = 5.9 out of 7 (SD = 1.4), attitude mean = 5.8 (SD = 1.1), subjective norm mean = 5.8 (SD = 1.1) and PBC mean = 6.2 (SD = 1.0). The arms did not significantly differ post-intervention on any of the theory-based constructs, suggesting a possible ceiling effect. Content analysis of perceived barriers suggested post-intentional barriers to prescribing thiazides most often focused on specific patient clinical characteristics and potential side effects. Baseline intention (β = 0.63, p < 0.01) but not PBC (β = 0.04, p = 0.78) predicted 42.6 % of the variance in self-reported behaviour at follow-up in the control group.

CONCLUSIONS

Congruent with the Ontario Printed Educational Messages trial results and aligned with the TPB, we saw no impact of the intervention on any TPB constructs. The theoretical basis of this evaluation suggests possible explanations for the failure of the PEM intervention to change professional behaviour, which can directly inform the design and content of future theory-based PEM interventions to change professional behaviour.

TRIAL REGISTRATION

ISRCTN, Canada ISRCTN72772651.

Behaviour change techniques: the development and evaluation of a taxonomic method for reporting and describing behaviour change interventions (a suite of five studies involving consensus methods, randomised controlled trials and analysis of qualitative data)

BACKGROUND

Meeting global health challenges requires effective behaviour change interventions (BCIs). This depends on advancing the science of behaviour change which, in turn, depends on accurate intervention reporting. Current reporting often lacks detail, preventing accurate replication and implementation. Recent developments have specified intervention content into behaviour change techniques (BCTs) - the 'active ingredients', for example goal-setting, self-monitoring of behaviour. BCTs are 'the smallest components compatible with retaining the postulated active ingredients, i.e. the proposed mechanisms of change. They can be used alone or in combination with other BCTs' (Michie S, Johnston M. Theories and techniques of behaviour change: developing a cumulative science of behaviour change. Health Psychol Rev 2012;6:1-6). Domain-specific taxonomies of BCTs have been developed, for example healthy eating and physical activity, smoking cessation and alcohol consumption. We need to build on these to develop an internationally shared language for specifying and developing interventions. This technology can be used for synthesising evidence, implementing effective interventions and testing theory. It has enormous potential added value for science and global health.

OBJECTIVE

(1) To develop a method of specifying content of BCIs in terms of component BCTs; (2) to lay a foundation for a comprehensive methodology applicable to different types of complex interventions; (3) to develop resources to support application of the taxonomy; and (4) to achieve multidisciplinary and international acceptance for future development.

DESIGN AND PARTICIPANTS

Four hundred participants (systematic reviewers, researchers, practitioners, policy-makers) from 12 countries engaged in investigating, designing and/or delivering BCIs. Development of the taxonomy involved a Delphi procedure, an iterative process of revisions and consultation with 41 international experts; hierarchical structure of the list was developed using inductive 'bottom-up' and theory-driven 'top-down' open-sort procedures (n = 36); training in use of the taxonomy (1-day workshops and distance group tutorials) (n = 161) was evaluated by changes in intercoder reliability and validity (agreement with expert consensus); evaluating the taxonomy for coding interventions was assessed by reliability (intercoder; test-retest) and validity (n = 40 trained coders); and evaluating the taxonomy for writing descriptions was assessed by reliability (intercoder; test-retest) and by experimentally testing its value (n = 190).

RESULTS

Ninety-three distinct, non-overlapping BCTs with clear labels and definitions formed Behaviour Change Technique Taxonomy version 1 (BCTTv1). BCTs clustered into 16 groupings using a 'bottom-up' open-sort procedure; there was overlap between these and groupings produced by a theory-driven, 'top-down' procedure. Both training methods improved validity (both p < 0.05), doubled the proportion of coders achieving competence and improved confidence in identifying BCTs in workshops (both p < 0.001) but did not improve intercoder reliability. Good intercoder reliability was observed for 80 of the 93 BCTs. Good within-coder agreement was observed after 1 month (p < 0.001). Validity was good for 14 of 15 BCTs in the descriptions. The usefulness of BCTTv1 to report descriptions of observed interventions had mixed results.

CONCLUSIONS

The developed taxonomy (BCTTv1) provides a methodology for identifying content of complex BCIs and a foundation for international cross-disciplinary collaboration for developing more effective interventions to improve health. Further work is needed to examine its usefulness for reporting interventions.

FUNDING

This project was funded by the Medical Research Council Ref: G0901474/1. Funding also came from the Peninsula Collaboration for Leadership in Applied Health Research and Care.

How Effective are Behavior Change Interventions Based on the Theory of Planned Behavior?

Abstract. The theory of planned behavior (TPB) is a prominent framework for predicting and explaining behavior in a variety of domains. The theory is also increasingly being used as a framework for conducting behavior change interventions. In this meta-analysis, we identified 82 papers reporting results of 123 interventions in a variety of disciplines. Our analysis confirmed the effectiveness of TPB-based interventions, with a mean effect size of .50 for changes in behavior and effect sizes ranging from .14 to .68 for changes in antecedent variables (behavioral, normative, and control beliefs, attitude, subjective norm, perceived behavioral control, and intention). Further analyses revealed that the interventions’ effectiveness varied for the diverse behavior change methods. In addition, interventions conducted in public and with groups were more successful than interventions in private locations or focusing on individuals. Finally, we identified gender and education as well as behavioral domain as moderators of the interventions’ effectiveness.

Causal pathways linking environmental change with health behaviour change: Natural experimental study of new transport infrastructure and cycling to work

BACKGROUND

Mechanisms linking changes to the environment with changes in physical activity are poorly understood. Insights into mechanisms of interventions can help strengthen causal attribution and improve understanding of divergent response patterns. We examined the causal pathways linking exposure to new transport infrastructure with changes in cycling to work.

METHODS

We used baseline (2009) and follow-up (2012) data (N=469) from the Commuting and Health in Cambridge natural experimental study (Cambridge, UK). Exposure to new infrastructure in the form of the Cambridgeshire Guided Busway was defined using residential proximity. Mediators studied were changes in perceptions of the route to work, theory of planned behaviour constructs and self-reported use of the new infrastructure. Outcomes were modelled as an increase, decrease or no change in weekly cycle commuting time. We used regression analyses to identify combinations of mediators forming potential pathways between exposure and outcome. We then tested these pathways in a path model and stratified analyses by baseline level of active commuting.

RESULTS

We identified changes in perceptions of the route to work, and use of the cycle path, as potential mediators. Of these potential mediators, only use of the path significantly explained (85%) the effect of the infrastructure in increasing cycling. Path use also explained a decrease in cycling among more active commuters.

CONCLUSION

The findings strengthen the causal argument that changing the environment led to changes in health-related behaviour via use of the new infrastructure, but also show how some commuters may have spent less time cycling as a result.

Effectiveness of training on preventative nutritional behaviors for type-2 diabetes among the female adolescents: Examination of theory of planned behavior

BACKGROUND

Since type-2 diabetes is the most common chronic disease among Iranian female adolescents, we applied theory of planned behavior to examine the effect of training to intention to preventative nutritional behaviors for type-2 diabetes among female adolescents.

METHODS

In this experimental study 200 (11-14 year old) girls from 8 schools of Tehran city (100 in each intervention and control group) were recruited based on cluster sampling method during two stages. For intervention group, an educational program was designed based on the theory of planned behavior and presented in 6 workshop sessions to prevent type-2 diabetes. The data were collected before and two months after the workshops using a valid and reliable (α=0.72 and r=0.80) authormade questionnaire based on Ajzens TPB questionnaire manual. The data were analyzed using t-test, chi-square test and analysis of covariance.

RESULTS

Findings indicate that the two groups were homogeneous regarding the demographic characteristics before education, but the mean score of the theory components (attitudes, subjective norms, perceived behavioral control, and intention) was higher in the control group. Also, results showed all of the theory components significantly increased after the education in the intervention group (p=0.000).

CONCLUSION

Training based on the theory of planned behavior enhances the intention to adherence preventative nutritional behaviors for type-2 diabetes among the studied female adolescents.

Evidence from interventions based on theoretical models for lifestyle modification (physical activity, diet, alcohol and tobacco use) in primary care settings: A systematic review

OBJECTIVE

To determine the effectiveness of health promotion interventions based on theoretical models of behavioral change to modify the main lifestyle factors (physical activity, diet, alcohol and tobacco) in adults receiving primary health care (PHC).

METHODS

We searched the MEDLINE and Cochrane Database of Systematic Reviews from January 2000 to December 2012. Two reviewers independently performed the first screening of titles and abstracts, the methodological quality assessment using the lecturacritica.com tool, and the extraction of necessary data to systematize the available information.

RESULTS

Only few studies met the inclusion criteria (17 studies from 30 articles). Thirteen were randomized controlled trials, three systematic reviews, and one observational study. The transtheoretical model was the most frequent (13 studies), and obtained strong evidence of its effectiveness for dietary interventions in the short-term and for smoking cessation interventions in the long-term as compared to usual PHC practice. Limited evidence was found for smoking cessation interventions based in the social cognitive theory.

CONCLUSION

There are few studies that explicitly link intervention strategies and theories of behavioral change. A rigorous evaluation of the theoretical principles could help researchers and practitioners to understand how and why interventions succeed or fail.

Impact of Education Based on Theory of Planned Behavior: An Investigation into Hypertension-Preventive Self-care Behaviors in Iranian Girl Adolescent

BACKGROUND

Since risk factors of hypertension are formed during adolescent period and regarding that attitudes change occurs more easily in these ages, the present paper aimed to evaluate the impact of education based on the theory of planned behavior in hypertension prevention behaviors in female adolescent students.

METHODS

In this quasi-experimental study, 160 girls of 12-16 yr old (80 in each case and control group), who had not been educated in prevention of hypertension over the recent three months, participated. Four schools in Tehran were selected based on cluster sampling method during two stages. The education was provided based on the theory of planned behavior in two sections (nutrition and physical activity) in four sessions. Data gathered before and after education through a two-part valid and reliable questionnaire. The results were analyzed based on SPSS software, version 17.

RESULTS

The results of independent t-test showed in the nutrition section, attitude (P=0.000), subjective norm (P=0.025), perceived control (P=0.016) and behavioral intention (P=0.025); significantly increased. About physical activity, except subjective norm (P=0.219), the mean score of the attitude (P=0.001), perceived control (P=0.000) and behavioral intention (P=0.000) revealed a significant difference between two groups.

CONCLUSION

Education based on the theory of planned behavior affects the intention of preventive behaviors of hypertension in female adolescents.

Patterns and predictors of changes in active commuting over 12 months

OBJECTIVE

To assess the predictors of uptake and maintenance of walking and cycling, and of switching to the car as the usual mode of travel, for commuting.

METHODS

655 commuters in Cambridge, UK reported all commuting trips using a seven-day recall instrument in 2009 and 2010. Individual and household characteristics, psychological measures relating to car use and environmental conditions on the route to work were self-reported in 2009. Objective environmental characteristics were assessed using Geographical Information Systems. Associations between uptake and maintenance of commuting behaviours and potential predictors were modelled using multivariable logistic regression.

RESULTS

Mean within-participant changes in commuting were relatively small (walking: +3.0 min/week, s.d.=66.7; cycling: -5.3 min/week, s.d.=74.7). Self-reported and objectively-assessed convenience of public transport predicted uptake of walking and cycling respectively, while convenient cycle routes predicted uptake of cycling and a pleasant route predicted maintenance of walking. A lack of free workplace parking predicted uptake of walking and alternatives to the car. Less favourable attitudes towards car use predicted continued use of alternatives to the car.

CONCLUSIONS

Improving the convenience of walking, cycling and public transport and limiting the availability of workplace car parking may promote uptake and maintenance of active commuting.

Incorporating walking or cycling into car journeys to and from work: the role of individual, workplace and environmental characteristics

OBJECTIVE

Small increases in walking or cycling for transport could contribute to population health improvement. We explore the individual, workplace and environmental characteristics associated with the incorporation of walking and cycling into car journeys.

METHODS

In 2009, participants from the Commuting and Health in Cambridge study (UK) reported transport modes used on the commute in the last week as well as individual, workplace and environmental characteristics. Logistic regression was used to assess the explanatory variables associated with incorporating walking or cycling into car commuting journeys.

RESULTS

31% of car commuters (n=419, mean age 43.3 years, SD 0.3) regularly incorporated walking or cycling into their commute. Those without access to car parking at work (OR: 26.0, 95% CI:11.8 to 57.2) and who reported most supportive environments for walking and cycling en route to work (highest versus lowest tertile, OR: 2.7, 95% CI 1.4 to 5.5) were more likely to incorporate walking or cycling into their car journeys.

CONCLUSIONS

Interventions that provide pleasant and convenient routes, limit or charge for workplace car parking and provide free off-site car parking may encourage car commuters to incorporate walking and cycling into car journeys. The effects of such interventions remain to be evaluated.

A 12-week multidomain intervention versus active control to reduce risk of Alzheimer's disease: study protocol for a randomized controlled trial

BACKGROUND

Disappointing results from clinical trials of disease-modifying interventions for Alzheimer's dementia (AD), along with reliable identification of modifiable risk factors in mid life from epidemiological studies, have contributed to calls to invest in risk-reduction interventions. It is also well known that AD-related pathological processes begin more than a decade before the development of clinical signs. These observations suggest that lifestyle interventions might be most effective when targeting non-symptomatic adults at risk of AD. To date, however, the few dementia risk-reduction programs available have targeted individual risk factors and/or were restricted to clinical settings. The current study describes the development of an evidence-based, theoretically-driven multidomain intervention to reduce AD risk in adults at risk.

METHOD

The design of Body Brain Life (BBL) is a randomized controlled trial (RCT) to evaluate a 12-week online AD risk-reduction intervention. Eligible participants with several modifiable risk factors on the Australian National University (ANU) AD Risk Index (ANU-ADRI) are randomly allocated to an online only group, an online and face-to-face group, or an active control group. We aim to recruit 180 participants, to undergo a comprehensive cognitive and physical assessment at baseline, post-intervention, and 6-month follow-up assessment. The intervention comprises seven online modules (dementia literacy, risk factor education, engagement in physical, social, and cognitive lifestyles, nutrition, and health monitoring) designed using contemporary models of health behavior change.

DISCUSSION

The BBL program is a novel online intervention to reduce the risk of AD in middle-aged adults at risk. The trial is currently under way. It is hypothesized that participants in the intervention arms will make lifestyle changes in several domains, and that this will lead to a reduction in their AD risk profile. We also expect to show that health behavior change is underpinned by changes in psychological determinants of behavior. If successful, the findings will contribute to the development of further dementia risk reduction interventions, and thus contribute to the urgent need to lower dementia risk factors in the population to alter future projections of disease prevalence. Longer follow-up of BBL participants and replications using large samples are required to examine whether reduction in AD risk factors will be associated with reduced prevalence.

TRIAL REGISTRATION

Reg. no. ACTRN12612000147886.

Constructing multiplicative measures of beliefs in the theory of planned behaviour

OBJECTIVE

Commonly used theories in health psychology involve multiplicative composites of measures, which have been used as predictors, mediators, and outcomes. The chosen scaling system can affect correlations with other variables. This study evaluated how best to construct composites in the context of the theory of planned behaviour (TPB), using hierarchical linear regression, a priori defined scaling systems, and optimal scaling.

DESIGN

Longitudinal.

METHODS

At baseline, 6 and 12 months, 365 trial participants (ProActive) completed questionnaires assessing salient beliefs, which were used to construct composites (indirect measures), and direct measures of instrumental and affective attitude, subjective norm, and perceived behavioural control towards becoming more physically active over the next 12 months.

RESULTS

Linear regression supported a multiplicative model for indirect instrumental attitude and perceived control. Except for perceived control, associations between composites and direct measures were unaffected by different a priori scaling systems. Optimal scaling produced widely differing composites over time for subjective norm and affective attitude and a negative association between composite and direct measure for subjective norm.

CONCLUSIONS

We recommend that researchers who use multiplicative composites first establish clear support for a multiplicative model, before they examine a range of meaningful scaling systems on theoretical and empirical grounds. Caution is needed when using optimal scaling without checking that a multiplicative model is supported and the resulting scaling system meaningful.

STATEMENT OF CONTRIBUTION

What is already known on this subject? Multiplicative composites are included in commonly used theories in health psychology (e.g., theory of planned behaviour). Valid measures are needed as the choice of scaling system (e.g., unipolar or bipolar) can affect estimates of associations between composites and other variables. Ajzen has advocated the use of optimal scaling. What does this study add? The study shows that optimal scaling can result in meaningless measures. We recommend that health psychologists use optimal scaling with great caution and we provide alternative recommendations for constructing composites.

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.

Changing the odds. What do we learn from prevention studies targeted at people with a positive family history of type 2 diabetes?

People with a positive family history of type 2 diabetes (T2DM) are at high risk of developing diabetes. We set out to review the literature reporting on the development and/or evaluation of lifestyle interventions specifically aimed at prevention of T2DM in this group. Targeting people with a positive family history of T2DM seems so far an underutilized prevention strategy. They can and should be approached with the aim to raise risk awareness and promote healthy eating, weight loss and physical activity, thereby reducing their risk of developing diabetes.

Correlates of time spent walking and cycling to and from work: baseline results from the commuting and health in Cambridge study

PURPOSE

Environmental perceptions and psychological measures appear to be associated with walking and cycling behaviour; however, their influence is still unclear. We assessed these associations using baseline data from a quasi-experimental cohort study of the effects of major transport infrastructural developments in Cambridge, UK.

METHODS

Postal surveys were sent to adults who travel to work in Cambridge (n = 1582). Questions asked about travel modes and time spent travelling to and from work in the last week, perceptions of the route, psychological measures regarding car use and socio-demographic characteristics. Participants were classified into one of two categories according to time spent walking for commuting ('no walking' or 'some walking') and one of three categories for cycling ('no cycling', '1-149 min/wk' and ' ≥ 150 min/wk').

RESULTS

Of the 1164 respondents (68% female, mean (SD) age: 42.3 (11.4) years) 30% reported any walking and 53% reported any cycling to or from work. In multiple regression models, short distance to work and not having access to a car showed strong positive associations with both walking and cycling. Furthermore, those who reported that it was pleasant to walk were more likely to walk to or from work (OR = 4.18, 95% CI 3.02 to 5.78) and those who reported that it was convenient to cycle on the route between home and work were more likely to do so (1-149 min/wk: OR = 4.60, 95% CI 2.88 to 7.34; ≥ 150 min/wk: OR = 3.14, 95% CI 2.11 to 4.66). Positive attitudes in favour of car use were positively associated with time spent walking to or from work but negatively associated with cycling to or from work. Strong perceived behavioural control for car use was negatively associated with walking.

CONCLUSIONS

In this relatively affluent sample of commuters, a range of individual and household characteristics, perceptions of the route environment and psychological measures relating to car use were associated with walking or cycling to and from work. Taken together, these findings suggest that social and physical contexts of travel decision-making should be considered and that a range of influences may require to be addressed to bring about behaviour change.

Examining determinants of self management behaviors in patients with diabetes: an application of the Theoretical Model of Effortful Decision Making and Enactment

OBJECTIVE

This study examined determinants of self-monitoring of blood glucose (SMBG) in patients with diabetes based on a theoretical model. The model focuses on two equally important components of the decision process within a single framework: (1) making a decision and (2) enacting the decision.

METHODS

Diabetes patients with HbA1c >7% and requiring insulin therapy were recruited from a southeastern Michigan healthcare system. Responses were elicited using a mail-in questionnaire. SMBG was measured using a two-week diary and two recall measures. The applicability of the theoretical model as it relates to SMBG was tested using structural equation modeling (SEM).

RESULTS

The SEM analysis demonstrated that goal desire is an antecedent to goal intentions and that implementation desire and implementation intentions mediate the path between goal intentions and SMBG. Further, implementation intentions are a significant predictor of SMBG.

CONCLUSION

Consistent with the theoretical model, results indicated that implementation desire and implementation intentions mediate the relationship between strength of goal intention and performing specific behaviors to achieve the goal.

PRACTICE IMPLICATIONS

It is evident that in order to be more effective, educational programs or interventions should consider incorporating implementation and action plans to help patients translate decisions and intentions into behavior.

Environmental and psychological correlates of older adult's active commuting

PURPOSE

This study explored the environmental and psychological correlates of active commuting in a sample of adults from the European Prospective Investigation into Cancer Norfolk cohort.

METHODS

Members of the cohort who were in employment, lived within 10 km of work, and did not report a limitation that precluded walking were included in this analysis. Psychological factors, perceptions of the neighborhood environment and travel mode to work were reported using questionnaires. Neighborhood and route environmental characteristics were estimated objectively using a geographical information system. The mediating effects of psychological factors were assessed using a series of regression models.

RESULTS

A total of 1279 adults (mean age=60.4 yr, SD=5.4 yr) were included in this analysis, of whom 25% actively commuted to work. In multivariable regression analyses, those who reported strong habits for walking or cycling were more likely to actively commute, whereas those living 4-10 km from work were less likely to actively commute. In addition, living in a rural area was associated with a decreased likelihood of men's active commuting, and in women, living in a neighborhood with high road density and having a route to work that was not on a main or secondary road was associated with an increased likelihood of active commuting. There was weak evidence that habit acted to partly mediate the associations between environmental correlates and active commuting in both sexes.

CONCLUSIONS

The findings suggest that interventions designed to encourage the development of habitual behaviors for active commuting may be effective, especially among those living close to work.

What are the most effective intervention techniques for changing physical activity self-efficacy and physical activity behaviour--and are they the same?

There is convincing evidence that targeting self-efficacy is an effective means of increasing physical activity. However, evidence concerning which are the most effective techniques for changing self-efficacy and thereby physical activity is lacking. The present review aims to estimate the association between specific intervention techniques used in physical activity interventions and change obtained in both self-efficacy and physical activity behaviour. A systematic search yielded 27 physical activity intervention studies for 'healthy' adults that reported self-efficacy and physical activity data. A small, yet significant (P < 0.01) effect of the interventions was found on change in self-efficacy and physical activity (d = 0.16 and 0.21, respectively). When a technique was associated with a change in effect sizes for self-efficacy, it also tended to be associated with a change (r(s) = 0.690, P < 0.001) in effect size for physical activity. Moderator analyses found that 'action planning', 'provide instruction' and 'reinforcing effort towards behaviour' were associated with significantly higher levels of both self-efficacy and physical activity. 'Relapse prevention' and 'setting graded tasks' were associated with significantly lower self-efficacy and physical activity levels. This meta-analysis provides evidence for which psychological techniques are most effective for changing self-efficacy and physical activity.

Overestimation of physical activity level is associated with lower BMI: a cross-sectional analysis

BACKGROUND

Poor recognition of physical inactivity may be an important barrier to healthy behaviour change, but little is known about this phenomenon. We aimed to characterize a high-risk population according to the discrepancies between objective and self-rated physical activity (PA), defined as awareness.

METHODS

An exploratory cross-sectional analysis of PA awareness using baseline data collected from 365 ProActive participants between 2001 and 2003 in East Anglia, England. Self-rated PA was defined as 'active' or 'inactive' (assessed via questionnaire). Objective PA was defined according to achievement of guideline activity levels (≥30 minutes or <30 minutes spent at least moderate intensity PA, assessed by heart rate monitoring). Four awareness groups were created: 'Realistic Actives', 'Realistic Inactives', 'Overestimators' and 'Underestimators'. Logistic regression was used to assess associations between awareness group and 17 personal, social and biological correlates.

RESULTS

63.3% of participants (N = 231) were inactive according to objective measurement. Of these, 45.9% rated themselves as active ('Overestimators'). In a multiple logistic regression model adjusted for age and smoking, males (OR = 2.11, 95% CI = 1.12, 3.98), those with lower BMI (OR = 0.89, 95% CI = 0.84, 0.95), younger age at completion of full-time education (OR = 0.83, 95% CI = 0.74, 0.93) and higher general health perception (OR = 1.02 CI = 1.00, 1.04) were more likely to overestimate their PA.

CONCLUSIONS

Overestimation of PA is associated with favourable indicators of relative slimness and general health. Feedback about PA levels could help reverse misperceptions.

The Southampton Initiative for Health: a complex intervention to improve the diets and increase the physical activity levels of women from disadvantaged communities

The Southampton Initiative for Health is a training intervention with Sure Start Children's Centre staff designed to improve the diets and physical activity levels of women of childbearing age. Training aims to help staff to support women in making changes to their lifestyles by improving three skills: reflection on current practice; asking 'open discovery' questions; and goal-setting. The impact of the training on staff practice is being assessed. A before and after non-randomized controlled trial is being used to evaluate the effectiveness and cost-effectiveness of the intervention in improving women's diets and increasing their physical activity levels.

Who will increase their physical activity? Predictors of change in objectively measured physical activity over 12 months in the ProActive cohort

Background

The aim was to identify predictors of change in objectively measured physical activity over 12 months in the ProActive cohort to improve understanding of factors influencing change in physical activity.

Methods

ProActive is a physical activity promotion trial that took place in Eastern England (1999-2004). 365 offspring of people with type 2 diabetes underwent measurement of physical activity energy expenditure (PAEE) using heart rate monitoring, fitness, and anthropometric and biochemical status at baseline and 1 year (n = 321). Linear regression was used to quantify the associations between baseline demographic, clinical, psychosocial and behavioural variables and change in PAEE over 12 months. This study is registered as ISRCTN61323766.

Results

ProActive participants significantly increased their PAEE by 0.6 kj/min (SD 4.2, p = 0.006) over one year, the equivalent of around 20 minutes brisk walking/day. Male sex and higher fitness at baseline predicted increase in PAEE. No significant associations were found for any other variables. Very few baseline demographic, clinical, psychosocial and behavioural predictors were associated with change in objectively measured physical activity.

Conclusions

Traditional baseline determinants of self-reported physical activity targeted by behavioural interventions may be relatively weak predictors of change in objectively measured physical activity. Further research is needed to improve our understanding of factors influencing change in physical activity to inform the development and targeting of interventions.

Perceptions of heart attack risk amongst individuals with diabetes

AIM

Individuals with diabetes are at increased risk of cardiovascular disease (CVD). There is good evidence that this risk can be reduced by pharmacotherapies and lifestyle modification. Despite this, knowledge of CVD risk amongst individuals with diabetes remains poor. We undertook a qualitative study to investigate lay perceptions of heart attack risk amongst individuals with diabetes in order to gather information about underlying perceptions concerning risk and risk reduction strategies.

METHODS

We conducted three focus groups in Oxford using an open-ended question map. Content analysis was performed to identify recurring themes, similar patterns, distinctions and supportive quotations.

RESULTS

Concern about having a heart attack varied widely. A commonly held view was that a 10-year heart attack risk of 10% or greater was high and being aware of one's risk was important so that lifestyle changes or other interventions could be implemented. Participants consistently viewed physical activity as potentially harmful. Almost all participants sought healthcare and lifestyle advice from their primary healthcare providers in the first instance, preferring this to information in the lay press or government campaigns.

CONCLUSION

The focus groups have allowed us to better understand lay perceptions of, and underlying assumptions about, CVD risk. These findings may be of use when discussing CVD risk and risk reduction strategies in primary care.