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How does change occur following a theoretically based self-management intervention for type 2 diabetes
Abstract and Figures
The purpose of this study was to test the extent that constructs from two theoretical models (self-regulatory theory and social cognitive theory) mediated change in outcomes following a self-management intervention. One hundred and twenty four individuals with type 2 diabetes who had participated in a randomised controlled trial of a diabetes self-management programme were analysed for the extent that illness beliefs and self-efficacy mediated change in self-management behaviours and illness specific quality of life. Exercise specific self-efficacy significantly mediated change in exercise at three months (B = .03; .01, p < .05) while monitoring specific self-efficacy mediated change in monitoring behaviour at both three (B = .04; .01, p < .01) and nine months follow-up (B = 5.97; 1.01, p < .01). Belief in control over diabetes mediated change in illness specific quality of life at three months (B = -.07; .28, p < .05) and nine months (B = .79; .28, p < .01) follow-ups, as well as change in exercise behaviour at immediately post-intervention (B = -.12; .17, p < .05). Behaviour-specific self-efficacy may have a stronger role in mediating self-management behaviours than illness beliefs; however, belief in control over diabetes may be important to manipulate for change in quality of life. This suggests different theoretical constructs may mediate change dependent on outcome.
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... Wang et al., 2018;Wilcox et al., 2008). There were five studies conducted in the UK (Benitez et al., 2015;Clarkson et al., 2009;Jolly et al., 2018;Mason et al., 2012;Steed et al., 2014) and three in Sweden (Fritz et al., 2019;Milos et al., 2013;Zakrisson et al., 2019) and one each from New Zealand (Whittaker et al., 2011), Brazil (Meurer et al., 2019, Colombia (Morales et al., 2019), Belgium (Dobbels et al., 2017), Australia (James et al., 2017), Netherland (Bouma et al., 2018), Canada , Spain (López et al., 2007), and Botswana (Norr et al., 2004). Only three of the included studies were conducted in Asia; one each from This preprint research paper has not been peer reviewed. ...
... Electronic copy available at: https://ssrn.com/abstract=4298109 P r e p r i n t n o t p e e r r e v i e w e d Mason et al., 2012;Mayor et al., 2010;Meurer et al., 2019;Milos et al., 2013;Miura et al., 2004;Peterson et al., 2012;Pinto et al., 2002;Pinto et al., 2001;Steed et al., 2014;H.-y. Wang et al., 2018;Whittaker et al., 2011;Zakrisson et al., 2019). ...
... The eligibility criteria of the participants varied across study designs. Two of the studies (Glasgow et al., 2006;Steed et al., 2014) included patients with Type-2 diabetes, and three studies (Coultas et al., 2018;Jolly et al., 2018;Zakrisson et al., 2019) included patients with physician-diagnosed chronic obstructive pulmonary disease (COPD), and two studies (Ihwanudin et al., 2015;Miura et al., 2004) included patients with hypertension. Only one study of the included 39 studies recruited young adolescents aged 15-19 as the study participant (Morales et al., 2019). ...
... Those not reporting the objective outcomes at any follow-ups were considered to have unclear risk. The risk of bias due to incomplete outcome data was considered high in four studies (Sturt et al. 2008, Mohamed et al. 2013, Mash et al. 2014, Steed et al. 2014, because the amount of missing data was large or not appropriately handled or having significance difference between completers and dropouts. For the remaining studies the risk of bias was low or unclear. ...
... We judged the reporting bias by looking at whether the expected outcomes stated in the articles were reported at the end. The risk of bias due to selective reporting was judged low for all studies, except for the unclear risk in two studies which did not give sufficient information for all expected outcomes (Beverly et al. 2013, Steed et al. 2014. ...
... We pooled the results of 16 studies for the random-effects meta-analysis of theory-based educational interventions on HbA1c (Figure 3a). One study was not pooled for HbA1c as the endpoint of nine months' follow-up was not stated in the article (Steed et al. 2014). Compared with routine care, theory-based self-management educational interventions were more likely to reduce HbA1c; the pooled WMD was À0Á38 (Unit: %), 95%CI [À0Á51, À0Á26]. ...
Aim:
To synthesize the effects of theory-based self-management educational interventions on patients with type 2 diabetes (T2DM) in randomized controlled trials.
Background:
Type 2 diabetes is a common chronic disease causing complications that put a heavy burden on society and reduce the quality of life of patients. Good self-management of diabetes can prevent complications and improve the quality of life of T2DM patients.
Design:
Systematic review with meta-analysis of randomized controlled trials following Cochrane methods.
Data resources:
A literature search was carried out in the MEDLINE, EMBASE, CINAHL, PSYCINFO, and Web of Science databases (1980-April 2015).
Review methods:
The risk of bias of these eligible studies was assessed independently by two authors using the Cochrane Collaboration's tool. The Publication bias of the main outcomes was examined. Statistical heterogeneity and random-effects model were used for meta-analysis.
Results:
Twenty studies with 5802 participants met the inclusion criteria. The interventions in the studies were based on one or more theories which mostly belong to mid-range theories. The pooled main outcomes by random-effects model showed significant improvements in HbA1c, self-efficacy, and diabetes knowledge, but not in BMI. As for quality of life, no conclusions can be drawn as the pooled outcome became the opposite with reduced heterogeneity after one study was excluded. No significant publication bias was found in the main outcomes.
Conclusion:
To get theory-based interventions to produce more effects, the role of patients should be more involved and stronger and the education team should be trained beyond the primary preparation for the self-management education program.
... In a RCT study, a program for improvement of worksite lifestyle in prediabetes employees resulted in better behavioral outcomes such as PA and diet self-efficacy and goal commitment [40]. A self-management coaching program on lifestyle changes had more impact on people with lower selfefficacy [41] and social cognitive (self-efficacy) and selfregulatory (illness beliefs) theory-based intervention programs caused a significant improvement in self-efficacy for exercise [42]. Data showed that illness beliefs play an essential role in patients' quality of life, while self-efficacy had a crucial role in self-management behaviors diabetes care providers [42]. ...
... A self-management coaching program on lifestyle changes had more impact on people with lower selfefficacy [41] and social cognitive (self-efficacy) and selfregulatory (illness beliefs) theory-based intervention programs caused a significant improvement in self-efficacy for exercise [42]. Data showed that illness beliefs play an essential role in patients' quality of life, while self-efficacy had a crucial role in self-management behaviors diabetes care providers [42]. ...
Objective:
The purpose of this systematic review is to study the impact of self-efficacy-improving strategies on physical activity-related glycemic control of diabetes.
Method:
This systematic review was conducted based on the PRISMA statement. ("Diabetes" OR "glycemic control") AND ("exercise" OR "physical activity") AND "self-efficacy" were searched as keywords in databases including PubMed, Google Scholar, Science Direct, Embase, Cochrane, Web of Science, and Scopus between 2000 and 2019 for relesvant articles.
Results:
Two reviewers independently screened articles (n = 400), and those meeting eligibility criteria (n = 47) were selected for data extraction using a predesigned Excel form and critical appraisal using the "Tool for Quantitative Studies." Different strategies and health promotion programs such as individual or group face-to-face education and multimedia (video conference, video, phone calls, short message service, and Internet-based education) were used in diabetes self-management education programs. The results of different interventions including motivational interviewing (7 studies), exercise (5 studies), multidimensional self-management programs (25 studies), and electronic education (11 studies) had been evaluated. Interventions with more social support, longer duration, combined educative theory-based, and individual education had better outcomes both in postintervention and in follow-up evaluation.
Conclusion:
A combination of traditional and virtual long-lasting self-care promoting (motivating) programs is needed to improve patients' self-efficacy for healthy habits like active lifestyle.
... Regarding mediation, the intervention may have not sufficiently targeted social support and self-efficacy. Other unmeasured mediators, such as diabetes knowledge or perceived control, may account for improvements in self-management behaviors [51], which should be measured in future studies. Furthermore, null findings for social support may reflect that the measure assessed support mainly from family and friends, which may not have been substantially improved by the intervention. ...
People with low incomes have a disproportionate prevalence of diabetes and its complications and experience many barriers to self-management, which community health workers (CHWs) may help address. We sought to examine the effects of an in-home CHW-led intervention for adults with diabetes and incomes <250% of the federal poverty line on self-management behaviors and test mediators and moderators. From 2010 to 2013, we randomized participants from three Washington State health systems with type 2 diabetes and hemoglobin A1c (HbA1c) ≥ 8% to the CHW intervention (N = 145) or usual care control (N = 142) arms. We examined effects on 12-month self-management: physical activity, dietary behaviors, medication taking, blood glucose monitoring, foot care, and tobacco use. For behaviors with significant intervention-control group differences, we tested mediation by self-efficacy and social support. We also investigated whether intervention-associated changes in behaviors varied by race/ethnicity, gender, and baseline values of HbA1c, diabetes distress, depression, and food insecurity (moderators). Compared to controls, intervention participants engaged in more physical activity and reported better dietary behaviors for some measures (general diet, frequency of skipping meals, and frequency of eating out) at 12-months, but there was no evidence of mediation by self-efficacy or social support. Evidence of moderation was limited: improvements in the frequency of skipping meals were restricted to participants with baseline HbA1c < 10%. Study findings suggest CHWs could be integrated into diabetes care to effectively support lifestyle changes around physical activity and some eating behaviors among adults with low incomes. More research is needed to understand mechanisms of change.
... Change in behavior, according to DiClemente and Prochaska, occurs slowly where one journeys through five stages-pre-contemplation, contemplation, preparation, action, and maintenance-before one is truly ready to make a change. The expectation that a patient diagnosed with T2DM will automatically change his or her lifestyle is unrealistic (Steed, Barnard, Hurel, Jenkins, & Newman, 2014). Providers understand this, yet the expectation for the patient to change is ever present and often drives providers to categorize a patient's lack of change as "nonadherence" or "noncompliance." ...
The aim of this study was to understand and describe the experience of diabetes self-management among patients not meeting glycemic control (A1C > 9). Type 2 diabetes mellitus (T2DM) is a complex chronic disease process. Diabetes self-management is equally complex and critical to patient outcomes and quality of life. The components for self-management include: knowledge, skills/abilities, and support. Few studies have reported on the experiences of self-management for patients with T2DM to reach and sustain glycemic control. This study used a qualitative descriptive design. Semistructured interviews were conducted with 13 patients receiving care at a diabetic clinic at a major health-care system in New York City. An interview guide was developed based on diabetes self-management which guided the interviews. All data were analyzed using qualitative content analysis. Initially, three themes that describe each component of diabetes mellitus self-management (DMSM) and impact the patients’ reaching the desired outcome were identified: acceptance of knowledge, motivation for skills and abilities, and variability and vulnerability of support. Further analysis of the three themes led to the identification of an overarching, theme: loss of self. This overarching theme helped to explain the stages of grief illustrated across the themes in the participants DMSM experiences. The participants in this study identified loss of self, and the accompanying grief and grieving process related to the loss of self in response to their T2DM diagnosis. Participants were “stuck” in a stage of loss of self, which presented challenges to acceptance of their diagnosis, barriers to DMSM, and optimizing glycemic control.
Background: Using a theoretical perspective to guide research design and implementation can result in a coherent preventative intervention model. Among theoretical frameworks, Bandura's Social Cognitive Theory (SCT) is particularly useful for studies focused on behavior change in health promotion research. Objective: This scoping review explored and summarized the current evidence on health promotion interventions that integrated constructs of Social Cognitive Theory and the outcome of those interventions in primary care settings. Method: ology: We conducted this scoping review using the PRISMA scoping review guidelines; we reviewed articles from five electronic databases and additional sources that were peer-reviewed journal articles reporting interventions applying SCT constructs and synthesized the outcomes following the interventions. Results: Among 849 retrieved from multiple sources, 39 articles met our eligibility criteria. Most studies (n = 19) were conducted in the United States. Twenty-six studies followed a randomized control trial design. Most studies (n = 26) recruited participants utilizing the primary care network. All 39 studies mentioned “self-efficacy” as the most utilized construct of SCT to determine how behavior change operates, followed by “observational learning” through role models. Twenty-three studies integrated individual (face-to-face) or peered group-based counseling-training programs; eight interventions used telephonic health coaching by a specialist; eight studies used audio-visual mediums. All included studies reported positive health outcomes following the intervention, including increased self-reported moderate-to-vigorous physical activity, increased Knowledge of dietary intake, high-risk behaviors such as STIs transmission, adapting to a healthy lifestyle, and adherence to post-transplant medication. Conclusion: Current evidence suggests that SCT-based interventions positively impact health outcomes and intervention effectiveness. The results of this study indicate the importance of incorporating and assessing several conceptual structures of behavioral theories when planning any primary care health promotion practice.
Objectives
Based on the common-sense model of self-regulation, this study aimed to explicate the mechanism underlying the effect of illness representations on self-care behaviours and anxiety symptoms among patients with type 2 diabetes.
Methods
A telephone survey was administered to 473 patients in Hong Kong. Structural equation modelling was used to test if threat and control perceptions regarding diabetes would be associated with self-reported self-care behaviours and anxiety symptoms through adoption of adaptive/maladaptive coping strategies and diabetes-related self-efficacy.
Results
Control perceptions but not threat perceptions were positively associated with self-care behaviours. Control perceptions had a positive indirect association with self-care behaviours through more problem-focused coping and diabetes-related self-efficacy. Threat perceptions simultaneously had a positive indirect association through more problem-focused coping and a negative indirect association through more avoidant coping and lower diabetes-related self-efficacy. In contrast, threat and control perceptions were positively and negatively, respectively, associated with anxiety symptoms. Problem-focused and avoidant coping consistently mediated the indirect association between threat perceptions and anxiety symptoms.
Conclusion
Threat and control perceptions were associated with diabetes self-care behaviours and anxiety symptoms through different self-regulation pathways.
Practice implications
Our findings inform possible targets for self-management interventions to simultaneously enhance self-care behaviours and alleviate diabetes-associated anxiety.
An existing systematic review and meta-analysis found a significant reduction in glycemic levels for adults with type 2 diabetes who received a psychological intervention over control conditions. To help develop effective interventions in the future, there is a need to understand the active ingredients which underpin these psychological interventions. We conducted a secondary meta-analysis including 67 randomized controlled trials (RCTs) reported in English. We reviewed the psychological intervention descriptions of the included studies of the existing review and extracted the behavior change techniques (BCTs) according to the BCT taxonomy (BCTTv1). We also extracted information on primary behavioral target versus primary outcome, and presence of fidelity assessment. The most frequent BCTs across RCTs were ‘social support (unspecified)’ (n=50), ‘problem solving’ (n=38) and ‘goal setting (behavior’) (n=30). These BCTs were independently associated with a significant reduction in glycemic levels (HbA1c) compared to control conditions, but not significantly different from studies that did not include these BCTs. Meta-regressions revealed no significant associations between HbA1c, and psychological intervention category (counselling versus cognitive behavioral therapy interventions) (p=0.84), frequency of BCTs per psychological intervention (p=0.29), primary behavioral target versus primary outcome (p=0.48), or presence of fidelity assessment (p=0.15). Social support (unspecified), problem solving, and goal setting (behavior) could be useful BCTs to develop psychological interventions for people with type 2 diabetes to improve glycemic levels. However, more research is required to understand which combination of individual BCTs are most effective for this population.
Systematic Review Registration
Registered with the international prospective register of systematic reviews registration (PROSPERO) CRD42016033619.
Background
For people with diabetes mellitus to achieve optimal glycaemic control, motivation to perform self-management is important. The research team wanted to determine whether or not psychological interventions are clinically effective and cost-effective in increasing self-management and improving glycaemic control.
Objectives
The first objective was to determine the clinical effectiveness of psychological interventions for people with type 1 diabetes mellitus and people with type 2 diabetes mellitus so that they have improved (1) glycated haemoglobin levels, (2) diabetes self-management and (3) quality of life, and fewer depressive symptoms. The second objective was to determine the cost-effectiveness of psychological interventions.
Data sources
The following databases were accessed (searches took place between 2003 and 2016): MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, PsycINFO, EMBASE, Cochrane Controlled Trials Register, Web of Science, and Dissertation Abstracts International. Diabetes conference abstracts, reference lists of included studies and Clinicaltrials.gov trial registry were also searched.
Review methods
Systematic review, aggregate meta-analysis, network meta-analysis, individual patient data meta-analysis and cost-effectiveness modelling were all used. Risk of bias of randomised and non-randomised controlled trials was assessed using the Cochrane Handbook (Higgins JP, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD, et al. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ 2011; 343 :d5928).
Design
Systematic review, meta-analysis, cost-effectiveness analysis and patient and public consultation were all used.
Setting
Settings in primary or secondary care were included.
Participants
Adolescents and children with type 1 diabetes mellitus and adults with types 1 and 2 diabetes mellitus were included.
Interventions
The interventions used were psychological treatments, including and not restricted to cognitive–behavioural therapy, counselling, family therapy and psychotherapy.
Main outcome measures
Glycated haemoglobin levels, self-management behaviours, body mass index, blood pressure levels, depressive symptoms and quality of life were all used as outcome measures.
Results
A total of 96 studies were included in the systematic review ( n = 18,659 participants). In random-effects meta-analysis, data on glycated haemoglobin levels were available for seven studies conducted in adults with type 1 diabetes mellitus ( n = 851 participants) that demonstrated a pooled mean difference of –0.13 (95% confidence interval –0.33 to 0.07), a non-significant decrease in favour of psychological treatment; 18 studies conducted in adolescents/children with type 1 diabetes mellitus ( n = 2583 participants) that demonstrated a pooled mean difference of 0.00 (95% confidence interval –0.18 to 0.18), indicating no change; and 49 studies conducted in adults with type 2 diabetes mellitus ( n = 12,009 participants) that demonstrated a pooled mean difference of –0.21 (95% confidence interval –0.31 to –0.10), equivalent to reduction in glycated haemoglobin levels of –0.33% or ≈3.5 mmol/mol. For type 2 diabetes mellitus, there was evidence that psychological interventions improved dietary behaviour and quality of life but not blood pressure, body mass index or depressive symptoms. The results of the network meta-analysis, which considers direct and indirect effects of multiple treatment comparisons, suggest that, for adults with type 1 diabetes mellitus (7 studies; 968 participants), attention control and cognitive–behavioural therapy are clinically effective and cognitive–behavioural therapy is cost-effective. For adults with type 2 diabetes mellitus (49 studies; 12,409 participants), cognitive–behavioural therapy and counselling are effective and cognitive–behavioural therapy is potentially cost-effective. The results of the individual patient data meta-analysis for adolescents/children with type 1 diabetes mellitus (9 studies; 1392 participants) suggest that there were main effects for age and diabetes duration. For adults with type 2 diabetes mellitus (19 studies; 3639 participants), baseline glycated haemoglobin levels moderated treatment outcome.
Limitations
Aggregate meta-analysis was limited to glycaemic control for type 1 diabetes mellitus. It was not possible to model cost-effectiveness for adolescents/children with type 1 diabetes mellitus and modelling for type 2 diabetes mellitus involved substantial uncertainty. The individual patient data meta-analysis included only 40–50% of studies.
Conclusions
This review suggests that psychological treatments offer minimal clinical benefit in improving glycated haemoglobin levels for adults with type 2 diabetes mellitus. However, there was no evidence of benefit compared with control interventions in improving glycated haemoglobin levels for people with type 1 diabetes mellitus.
Future work
Future work should consider the competency of the interventionists delivering a therapy and psychological approaches that are matched to a person and their life course.
Study registration
This study is registered as PROSPERO CRD42016033619.
Funding
This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 24, No. 28. See the NIHR Journals Library website for further project information.
Aims:
The aims of this study were to: a) determine if self-efficacy mediates the relationship between perceived stress and diabetes self-management in adolescents with type 1 diabetes; and b) explore whether perceived stress moderated the self-efficacy and diabetes self-management relationship.
Design:
Non-experimental, descriptive correlational design, conducted from January- December 2016.
Methods:
Guided by the Adaptation to Diabetes framework, data on demographic and clinical characteristics, perceived stress, self-efficacy and diabetes self-management were collected. Descriptive analyses and regression analyses were generated by SPSS Version 22. Structural equation modeling was implemented with the MPlus program.
Results:
There was no direct effect of perceived stress on diabetes self-management; however, self-efficacy mediated the relationship between perceived stress and diabetes self-management. Adolescents who had high self-efficacy and low perceived stress demonstrated better diabetes care activities and diabetes communication than would be predicted from the main effects of self-efficacy and perceived stress alone.
Conclusions:
Decreasing perceived stress and improving self-efficacy are important strategies to improve diabetes self-management in adolescents with type 1 diabetes.
Impact:
Adolescents with type 1 diabetes experience considerable stress with daily self-management demands. This study highlights the mediating role of self-efficacy on perceived stress and diabetes self-management. Assessment of perceived stress and self-efficacy in self-management tasks in adolescents with T1D may help nurses individualize self-management education and support. Incorporating strategies to promote stress management and self-efficacy in diabetes education may also improve diabetes self-management. This article is protected by copyright. All rights reserved.
In this article, we attempt to distinguish between the properties of moderator and mediator variables at a number of levels. First, we seek to make theorists and researchers aware of the importance of not using the terms moderator and mediator interchangeably by carefully elaborating, both conceptually and strategically, the many ways in which moderators and mediators differ. We then go beyond this largely pedagogical function and delineate the conceptual and strategic implications of making use of such distinctions with regard to a wide range of phenomena, including control and stress, attitudes, and personality traits. We also provide a specific compendium of analytic procedures appropriate for making the most effective use of the moderator and mediator distinction, both separately and in terms of a broader causal system that includes both moderators and mediators. (46 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Self-regulation systems are designed to adapt to threats via coping procedures that make efficient use of resources based upon valid representations of the environment. We discuss two components of the common-sense model of health threats: illness representations (e.g., content and organization) and coping procedures (e.g., classes of procedure and their attributes - outcome expectancies, time-lines, dose-efficacy beliefs, etc.). Characteristics of each of these domains, and the connection between the two, are critical to understanding human adaptation to problems of physical health. Rather than posing a barrier to factors outside the person that control behavior, an emphasis on subjective construal involves a view of the person as an active problem-solver embedded in a bidirectional system of sensitivity and responsiveness vis á vis the social, physical, and institutional environments in which health threats occur and through which intervention efforts may be directed.
This paper presents a revised version of the Illness Perception Questionnaire (IPQ-R), a recently developed and widely used quantitative measure of the five components of illness representations in Leventhal's self-regulatory model. The revised version stemmed from a need to deal with minor psychometric problems with two subscales, and to include additional subscales, assessing cyclical timeline perceptions, illness coherence, and emotional representations. Item selection was determined by principal components analyses which verified the factorial structure of the questionnaire in a sample of 711 patients from 8 different illness groups. Further analysis provided good evidence for both the internal reliability of the subscales and the short (3 week) and longer term (6 month) retest reliability. The IPQ-R also demonstrated sound discriminant, known group and predictive validity. While it is possible that the new subscales will vary in their applicability in different patient groups, the IPQ-R provides a more comprehensive and psychometrically acceptable assessment of the key components of patients' perceptions of illness.
This study investigated the mediating mechanisms responsible for the effects of a program designed to reduce intentions to use anabolic steroids, improve nutrition, and increase strength training self-efficacy. Fifteen of 31 high school football teams (N = 1,506 players at baseline) in Oregon and Washington were assigned to receive the intervention. The multicomponent program addressed the social influences promoting ergogenic drug use and engaging students in healthy nutrition and strength training alternative behaviors. Although the results differed across the three dependent variables, the program appeared to work by changing team norms. Unlike prevention of other drugs, changes in knowledge and perceived severity were mediators of program effects in this study.
To measure whether the benefits of a single education and self management structured programme for people with newly diagnosed type 2 diabetes mellitus are sustained at three years.
Three year follow-up of a multicentre cluster randomised controlled trial in primary care, with randomisation at practice level.
207 general practices in 13 primary care sites in the United Kingdom.
731 of the 824 participants included in the original trial were eligible for follow-up. Biomedical data were collected on 604 (82.6%) and questionnaire data on 513 (70.1%) participants.
A structured group education programme for six hours delivered in the community by two trained healthcare professional educators compared with usual care.
The primary outcome was glycated haemoglobin (HbA(1c)) levels. The secondary outcomes were blood pressure, weight, blood lipid levels, smoking status, physical activity, quality of life, beliefs about illness, depression, emotional impact of diabetes, and drug use at three years.
HbA(1c) levels at three years had decreased in both groups. After adjusting for baseline and cluster the difference was not significant (difference -0.02, 95% confidence interval -0.22 to 0.17). The groups did not differ for the other biomedical and lifestyle outcomes and drug use. The significant benefits in the intervention group across four out of five health beliefs seen at 12 months were sustained at three years (P<0.01). Depression scores and quality of life did not differ at three years.
A single programme for people with newly diagnosed type 2 diabetes mellitus showed no difference in biomedical or lifestyle outcomes at three years although there were sustained improvements in some illness beliefs.
Current Controlled Trials ISRCTN17844016.
Introduction: Behavioral science provides the foundation for physical activity interventions. The mediating variable framework is used to assess the status of physical activity interventions and the roles that are, or could be played, by behavioral theory.
This article presents the basic tenets of social cognitive theory. It is founded on a causal model of triadic reciprocal causation in which personal factors in the form of cognitive, affective and biological events, behavioral patterns, and environmental events all operate as interacting determinants that influence one another bidirectionally. Within this theory, human agency is embedded in a self theory encompassing self-organizing, proactive, self-reflective and self-regulative mechanisms. Human agency can be exercised through direct personal agency; through proxy agency relying on the efforts of intermediaries; and by collective agency operating through shared beliefs of efficacy, pooled understandings, group aspirations and incentive systems, and collective action. Personal agency operates within a broad network of sociostructural influences. In these agentic transactions, people are producers as well as products of social systems. Growing transnational imbeddedness and interdependence of societies are creating new social realities in which global forces increasingly interact with national ones to shape the nature of cultural life.
The statistical parameters that influence the reliability of delta and residualized change were examined in the context of the assessment of cardiovascular reactivity. A comparison of the relative reliabilities of these two quantification methods was performed using systolic blood pressure, diastolic blood pressure, and heart rate data from two samples of 134 and 109 subjects observed during baseline and either two or four behavioral challenges. The results indicated that both delta and residualized change scores can yield reliable measures of blood pressure and heart rate reactivity to behavioral challenges, and that their reliabilities will be comparable under the conditions observed in laboratory reactivity studies. Correlations between baseline and delta did not indicate that these two measures were systematically related. Finally, delta scores are more appropriate than residuals when assessing the generalizability of responses across a variety of tasks.