A cluster randomised controlled trial of an intervention based on the Health Action Process Approach for increasing fruit and vegetable consumption in Iranian adolescents

Changes of Health Outcomes, Healthy Behaviors, Generalized Trust, and Accessibility to Health Promotion Resources in Taiwan Before and During COVID-19 Pandemic: Comparing 2011 and 2021 Taiwan Social Change Survey (TSCS) Cohorts

PURPOSE

The present study compared two nationally representative cohort datasets concerning Taiwan residents' healthy behaviors, subjective health outcomes, generalized trust, and accessibility to health promotion resources.

PATIENTS AND METHODS

The Taiwan Social Change Survey (TSCS) was conducted in two waves ten years apart: 2011 cohort (n = 1021; 48.4% males) and 2021 cohort (n = 1425; 47.4%) cohorts. Descriptive statistics were calculated to compare the two TSCS datasets. Then, multiple regression models were constructed with health outcome as the dependent variable, and demographics and other key components as independent variables.

RESULTS

The 2011 TSCS cohort showed higher prevalence for cigarette smoking (30.8% vs 25.2%; p=0.002), alcohol drinking (52.5% vs 24.3%; p<0.001), exercise habits (52.7% vs 48.0%; p=0.02), and better fruit and vegetable accessibility (Mean=3.91 vs 3.82; p=0.04). The 2021 TSCS cohort reported higher body mass index (Mean=24.20 vs 23.63; p<0.001), less residency in urban areas (22.4% vs 31.1%; p<0.001), better jogging accessibility (4.14 vs 4.05; p=0.006), higher generalized trust (2.26 vs 2.17; p=0.001), and greater internet usage (3.43 vs 2.89; p<0.001). The regression model showed that exercise habits (standardized coefficient=0.20 and 0.10; p<0.001) and generalized trust (standardized coefficient=0.11 and 0.11; p=0.004 and <0.001) were consistently associated with health outcomes in both cohorts. Additionally, internet use (standardized coefficient=-0.07; p=0.026) and alcohol drinking behaviors (standardized coefficient=-0.07; p=0.0022) were negatively associated with health outcomes in the 2021 cohort.

CONCLUSION

The present study demonstrated the trends and changes over 10 years regarding multiple health-related components among Taiwan residents. The study's findings provide insight into education promotion programs to reduce unhealthy behaviors as well as enhancing generalized trust building and developing healthy behaviors for Taiwan residents.

The effectiveness of an intervention designed based on health action process approach on diet and medication adherence among patients with type 2 diabetes: a randomized controlled trial

BACKGROUND

Diabetes is a major cause of worldwide morbidity and mortality. Diet and medication non-adherence are common among individuals with diabetes, making glycemic control difficult to attain. This study aimed to evaluate an intervention designed based on Health Action Process Approach (HAPA) to improve adherence to diet and medication among patients with type 2 diabetes in Tehran, Iran.

METHODS

The study was a randomized controlled trial. A total of 248 patients with type 2 diabetes who had low diet and medication adherence were randomly allocated into two intervention (n  = 124) and control (n  = 124) groups. Intervention group received educational intervention during three months. HAPA constructs, diet and medication adherence, and Hemoglobin A1c (HbA1c) levels were assessed at baseline, one month and six months after the intervention. Mixed Model Analysis was used to compare between and within group changes in the outcomes.

RESULTS

There was a statistically significant improvement in HbA1c levels after six months (7.77 ± 1.36% vs. 8.07 ± 1.52%, 95% CI, p  < 0.001). Diet and medication adherence, intention, task self-efficacy, coping self-efficacy, recovery self-efficacy, action and coping planning, barriers, benefits and perceived social support were significantly improved one month and six months after the intervention (p  < 0.001).

CONCLUSION

Our intervention designed based on health action process approach led to improvements in diet and medication adherence, and HbA1c among the patients within one and six months.

TRIAL REGISTRATION

IRCT, IRCT20151208025431N4. Registered 10 March 2018, https://fa.irct.ir.

Suicidal Ideation during the COVID-19 Pandemic among A Large-Scale Iranian Sample: The Roles of Generalized Trust, Insomnia, and Fear of COVID-19

The novel 2019 coronavirus disease (COVID-19) is still not under control globally. The pandemic has caused mental health issues among many different cohorts and suicidal ideation in relation to COVID-19 has been reported in a number of recent studies. Therefore, the present study proposed a model to explain the associations between generalized trust, fear of COVID-19, insomnia, and suicidal ideation during the COVID-19 pandemic among a large-scale Iranian sample. Utilizing cluster sampling with multistage stratification, residents from Qazvin province in Iran were invited to participate in the present study. Adults aged over 18 years (n = 10,843; 6751 [62.3%] females) completed ‘paper–and-pencil’ questionnaires with the assistance of a trained research assistant. Structural equation modeling (SEM) was applied to understand the associations between generalized trust, fear of COVID-19, insomnia, and suicidal ideation. Slightly over one-fifth of the participants (n = 2252; 20.8%) reported suicidal ideation. Moreover, the SEM results indicated that generalized trust was indirectly associated with suicidal ideation via fear of COVID-19 and insomnia. Furthermore, generalized trust was not directly associated with suicidal ideation. The proposed model was invariant across gender groups, age groups, and participants residing in different areas (i.e., urban vs. rural). Generalized trust might reduce individuals’ suicidal ideation during the COVID-19 pandemic period via reduced levels of fear of COVID-19 and insomnia. Healthcare providers and policymakers may want to assist individuals in developing their generalized trust, reducing fear of COVID-19, and improving insomnia problems to avoid possible suicidal behaviors.

Trends in the Number of Behavioural Theory-Based Healthy Eating Interventions Inclusive of Dietitians/Nutritionists in 2000-2020

Nutrition interventions developed using behaviour theory may be more effective than those without theoretical underpinnings. This study aimed to document the number of theory-based healthy eating interventions, the involvement of dietitians/nutritionists and the behaviour theories employed from 2000 to 2020. We conducted a review of publications related to healthy eating interventions that used behaviour change theories. Interventional studies published in English between 2000 and 2020 were retrieved from searching Medline, Cinahl, Embase, Psycinfo and Cochrane Central. Citation, country of origin, presence or absence of dietitian/nutritionist authors, participants, dietary behaviours, outcomes, theories and any behaviour change techniques (BCTs) stated were extracted. The publication trends on a yearly basis were recorded. A total of 266 articles were included. The number of theory-based interventions increased over the two decades. The number of studies conducted by dietitians/nutritionists increased, but since 2012, increases have been driven by other researchers. Social cognitive theory was the most used behaviour theory. Dietitians/nutritionists contributed to growth in publication of theory-based healthy eating interventions, but the proportion of researchers from other professions engaged in this field increased markedly. The reasons for this growth in publications from other professions is unknown but conjectured to result from greater prominence of dietary behaviours within the context of an obesity epidemic.

Promoting Fruit and Vegetable Intake in Parents: A Cluster Randomised Controlled Trial

We conducted a cluster randomised controlled trial of parents in 56 primary schools and community service centres (clusters) to evaluate the effectiveness of a single-session workshop on promoting more fruit and vegetable (FV) intake. A total of 803 parents were randomised to the FV intervention arm (16 clusters, n = 197), the more appreciation control arm (19 clusters, n = 270), or the less criticism control arm (21 clusters, n = 336). The FV intake of the FV arm was compared with that of the combined more appreciation or less criticism (MALC) arm. Both arms received a 2 h workshop: (i) the FV arm on increasing FV consumption and related food literacy; (ii) the MALC arm on increasing appreciation or reducing criticism of children. Primary outcomes were FV consumption per day in the past week assessed at baseline, 2-weeks, and 6-weeks. Secondary outcomes were behavioural determinants proposed by the Health Action Process Approach (HAPA), including outcome expectancies, self-efficacy, intention, and planning behaviour. The FV arm had a greater increase in FV consumption than the MALC arm, with large effect sizes (d: 0.97–1.08) and improvements in behavioural determinants with small effect sizes at all time points (d: 0.19–0.43). Our study was the first population-based randomised controlled trial to show that a brief, single 2 h HAPA-based workshop was effective in promoting fruit and vegetable intake in parents.

Implementing Job Crafting Behaviors: Exploring the Effects of a Job Crafting Intervention Based on the Theory of Planned Behavior

This article presents a combined motivational and volitional intervention based on the theory of planned behavior aimed at promoting expansion-oriented job crafting behaviors. Participants were employees working in different companies, assigned to either an intervention ( n = 53) or a control group ( n = 55). Results of a field study (including premeasure, postmeasure, and weekly diaries) indicated that the intervention enhanced participants’ perceptions of behavioral control referred to job crafting and awareness regarding others’ engagement in job crafting. Latent change growth modeling showed that participation in the intervention led to participants shaping their job crafting intentions during the weeks, which translated into more frequent job crafting behaviors at the end of the study period. Besides, the intervention served to trigger weekly work-related flow experiences in terms of high absorption while working. Findings suggest that job crafting interventions can benefit from the inclusion of self-regulatory strategies complementing goal setting.

Using an integrated social cognition model to predict COVID-19 preventive behaviours

Objectives

Rates of novel coronavirus disease 2019 (COVID‐19) infections have rapidly increased worldwide and reached pandemic proportions. A suite of preventive behaviours have been recommended to minimize risk of COVID‐19 infection in the general population. The present study utilized an integrated social cognition model to explain COVID‐19 preventive behaviours in a sample from the Iranian general population.

Design

The study adopted a three‐wave prospective correlational design.

Methods

Members of the general public (N = 1,718, M_age = 33.34, SD = 15.77, male = 796, female = 922) agreed to participate in the study. Participants completed self‐report measures of demographic characteristics, intention, attitude, subjective norm, perceived behavioural control, and action self‐efficacy at an initial data collection occasion. One week later, participants completed self‐report measures of maintenance self‐efficacy, action planning and coping planning, and, a further week later, measures of COVID‐19 preventive behaviours. Hypothesized relationships among social cognition constructs and COVID‐19 preventive behaviours according to the proposed integrated model were estimated using structural equation modelling.

Results

The proposed model fitted the data well according to multiple goodness‐of‐fit criteria. All proposed relationships among model constructs were statistically significant. The social cognition constructs with the largest effects on COVID‐19 preventive behaviours were coping planning (β = .575, p < .001) and action planning (β = .267, p < .001).

Conclusions

Current findings may inform the development of behavioural interventions in health care contexts by identifying intervention targets. In particular, findings suggest targeting change in coping planning and action planning may be most effective in promoting participation in COVID‐19 preventive behaviours.

A theory-based intervention to promote medication adherence in patients with rheumatoid arthritis: A randomized controlled trial

Introduction/objectives

Adherence to prescribed medication regimens is fundamental to the improvement and maintenance of the health of patients with rheumatoid arthritis. It is therefore important that interventions are developed to address this important health behavior issue. The aim of the present study was to design and evaluate a theory-based intervention to improve the medication adherence (primary outcome) among rheumatoid arthritis patients.

Methods

The study adopted a pre-registered randomized controlled trial design. Rheumatoid arthritis patients were recruited from two University teaching hospitals in Qazvin, Iran from June 2018 to May 2019 and randomly assigned to either an intervention group (n = 100) or a treatment-as-usual group (n = 100). The intervention group received a theory-based intervention designed based on the theoretical underpinnings of the health action process approach (HAPA). More specifically, action planning (making detailed plans to follow medication regimen), coping planning (constructing plans to overcome potential obstacles that may arise in medication adherence), and self-monitoring (using a calendar to record medication adherence) of the HAPA has been used for the treatment. The treatment-as-usual group received standard care.

Results

Data analysis was conducted based on the principle of intention to treat. Using a linear mixed-effects model (adjusted for age, sex, medication prescribed, and body mass index), the results showed improved medication adherence scores in the intervention group (loss to follow-up = 16) compared to the treatment-as-usual group (loss to follow-up = 12) at the 3-month (coefficient = 3.9; SE = 0.8) and 6-month (coefficient = 4.5; SE = 0.8) follow-up. Intervention effects on medication adherence scores were found to be mediated by some of the theory-based HAPA variables that guided the study.

Conclusion

The results of the present study support the use of a theory-based intervention for improving medication adherence among rheumatoid arthritis patients, a group at-risk of not adhering to medication regimens.

Trial registration (in Iranian Registry of Clinical Trials)

irct.ir, IRCT20180108038271N1

Key Points • Theoretical underpinnings of the health action process approach are useful to improve medication adherence for RA patients.

Electronic supplementary material

The online version of this article (10.1007/s10067-020-05224-y) contains supplementary material, which is available to authorized users.

Caregiver involvement in interventions for improving children's dietary intake and physical activity behaviors

BACKGROUND

Poor diet and insufficient physical activity are major risk factors for non-communicable diseases. Developing healthy diet and physical activity behaviors early in life is important as these behaviors track between childhood and adulthood. Parents and other adult caregivers have important influences on children's health behaviors, but whether their involvement in children's nutrition and physical activity interventions contributes to intervention effectiveness is not known.

OBJECTIVES

• To assess effects of caregiver involvement in interventions for improving children's dietary intake and physical activity behaviors, including those intended to prevent overweight and obesity • To describe intervention content and behavior change techniques employed, drawing from a behavior change technique taxonomy developed and advanced by Abraham, Michie, and colleagues (Abraham 2008; Michie 2011; Michie 2013; Michie 2015) • To identify content and techniques related to reported outcomes when such information was reported in included studies SEARCH METHODS: In January 2019, we searched CENTRAL, MEDLINE, Embase, 11 other databases, and three trials registers. We also searched the references lists of relevant reports and systematic reviews.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of interventions to improve children's dietary intake or physical activity behavior, or both, with children aged 2 to 18 years as active participants and at least one component involving caregivers versus the same interventions but without the caregiver component(s). We excluded interventions meant as treatment or targeting children with pre-existing conditions, as well as caregiver-child units residing in orphanages and school hostel environments.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures outlined by Cochrane.

MAIN RESULTS

We included 23 trials with approximately 12,192 children in eligible intervention arms. With the exception of two studies, all were conducted in high-income countries, with more than half performed in North America. Most studies were school-based and involved the addition of healthy eating or physical education classes, or both, sometimes in tandem with other changes to the school environment. The specific intervention strategies used were not always reported completely. However, based on available reports, the behavior change techniques used most commonly in the child-only arm were "shaping knowledge," "comparison of behavior," "feedback and monitoring," and "repetition and substitution." In the child + caregiver arm, the strategies used most commonly included additional "shaping knowledge" or "feedback and monitoring" techniques, as well as "social support" and "natural consequences." We considered all trials to be at high risk of bias for at least one design factor. Seven trials did not contribute any data to analyses. The quality of reporting of intervention content varied between studies, and there was limited scope for meta-analysis. Both validated and non-validated instruments were used to measure outcomes of interest. Outcomes measured and reported differed between studies, with 16 studies contributing data to the meta-analyses. About three-quarters of studies reported their funding sources; no studies reported industry funding. We assessed the quality of evidence to be low or very low. Dietary behavior change interventions with a caregiver component versus interventions without a caregiver component Seven studies compared dietary behavior change interventions with and without a caregiver component. At the end of the intervention, we did not detect a difference between intervention arms in children's percentage of total energy intake from saturated fat (mean difference [MD] -0.42%, 95% confidence interval [CI] -1.25 to 0.41, 1 study, n = 207; low-quality evidence) or from sodium intake (MD -0.12 g/d, 95% CI -0.36 to 0.12, 1 study, n = 207; low-quality evidence). No trial in this comparison reported data for children's combined fruit and vegetable intake, sugar-sweetened beverage (SSB) intake, or physical activity levels, nor for adverse effects of interventions. Physical activity interventions with a caregiver component versus interventions without a caregiver component Six studies compared physical activity interventions with and without a caregiver component. At the end of the intervention, we did not detect a difference between intervention arms in children's total physical activity (MD 0.20 min/h, 95% CI -1.19 to 1.59, 1 study, n = 54; low-quality evidence) or moderate to vigorous physical activity (MVPA) (standard mean difference [SMD] 0.04, 95% CI -0.41 to 0.49, 2 studies, n = 80; moderate-quality evidence). No trial in this comparison reported data for percentage of children's total energy intake from saturated fat, sodium intake, fruit and vegetable intake, or SSB intake, nor for adverse effects of interventions. Combined dietary and physical activity interventions with a caregiver component versus interventions without a caregiver component Ten studies compared dietary and physical activity interventions with and without a caregiver component. At the end of the intervention, we detected a small positive impact of a caregiver component on children's SSB intake (SMD -0.28, 95% CI -0.44 to -0.12, 3 studies, n = 651; moderate-quality evidence). We did not detect a difference between intervention arms in children's percentage of total energy intake from saturated fat (MD 0.06%, 95% CI -0.67 to 0.80, 2 studies, n = 216; very low-quality evidence), sodium intake (MD 35.94 mg/d, 95% CI -322.60 to 394.47, 2 studies, n = 315; very low-quality evidence), fruit and vegetable intake (MD 0.38 servings/d, 95% CI -0.51 to 1.27, 1 study, n = 134; very low-quality evidence), total physical activity (MD 1.81 min/d, 95% CI -15.18 to 18.80, 2 studies, n = 573; low-quality evidence), or MVPA (MD -0.05 min/d, 95% CI -18.57 to 18.47, 1 study, n = 622; very low-quality evidence). One trial indicated that no adverse events were reported by study participants but did not provide data.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support the inclusion of caregiver involvement in interventions to improve children's dietary intake or physical activity behavior, or both. For most outcomes, the quality of the evidence is adversely impacted by the small number of studies with available data, limited effective sample sizes, risk of bias, and imprecision. To establish the value of caregiver involvement, additional studies measuring clinically important outcomes using valid and reliable measures, employing appropriate design and power, and following established reporting guidelines are needed, as is evidence on how such interventions might contribute to health equity.

Can a modified theory of planned behavior explain the effects of empowerment education for people with type 2 diabetes?

BACKGROUND

The effectiveness of the Patient Empowerment Program (PEP) has been demonstrated in people with diabetes mellitus (DM); however, the underlying reasons for its effectiveness remain unclear. To improve effectiveness, we need to study the psychological mechanism(s) of PEP to understand why it is effective. This study hypothesized that the Theory of Planned Behavior (TPB), modified specifically for people with DM, could describe the mechanism explaining PEP effects.

METHODS

A longitudinal design was used. Patients with type 2 DM (n = 365; 151 males; mean age = 62.9 ± 9.6 years) received two education sessions (i.e. seminars delivered by registered nurses to provide disease-specific knowledge), and some (n = 210) further enrolled afterwards in five empowerment sessions (i.e. small-group interactive workshops conducted by social workers to practice action planning, problem solving, and experience sharing). Validated questionnaires were used to measure risk perception, health literacy, attitude, subjective norm, perceived behavioral control and behavioral intention on diabetes self-care behaviors, and four diabetes self-care behaviors (diet control, exercise, blood glucose monitoring, and foot care) at baseline. Three months later (i.e. at the end of PEP), all participants completed the behavioral intention and diabetes self-care behaviors measures again. Attitude, subjective norm, perceived behavioral control, behavioral intention, and diabetes self-care behaviors were assessed to represent the TPB constructs. Risk perception and health literacy elements relevant to people with DM were assessed and added to modify the TPB.

RESULTS

The behavioral intention was associated with three diabetes self-care behaviors: exercise, blood glucose monitoring, and foot care. The behavioral intention was found to be a significant mediator in the following relationships: empowerment session participation and exercise (β = 0.045, p = 0.04), and empowerment session participation and foot care (β = 0.099, p < 0.001).

CONCLUSIONS

The effects of enrollment of empowerment sessions in PEP on exercise and foot care were likely to be mediated through behavioral intention.

An App to Improve Eating Habits of Adolescents and Young Adults (Challenge to Go): Systematic Development of a Theory-Based and Target Group-Adapted Mobile App Intervention

Background

Due to the widespread use of mobile phones, dietary mobile apps are promising tools for preventing diet-related noncommunicable diseases early in life. However, most of the currently available nutrition apps lack scientific evaluation and user acceptance.

Objective

The objective of this study was the systematic design of a theory-driven and target group–adapted dietary mobile app concept to promote healthy eating habits with a focus on drinking habits as well as consumption of fruits and vegetables in adolescents and young adults, especially from disadvantaged backgrounds.

Methods

The design process was guided by the behavior change wheel (BCW). The development process comprised 3 stages. In stage 1, the target behavior was specified, and facilitators and barriers were identified. Furthermore, important insights into target group interests, needs, and values in the field of nutrition and apps were revealed. To this end, 2 empirical studies were conducted with the target group. In stage 2, results of stage 1 were translated into behavior change techniques (BCTs) and, finally, into app functionalities and features. Consequently, in stage 3, the concept was evaluated and optimized through expert interviews.

Results

Facilitators and barriers for achieving the target behavior were psychological capabilities (eg, self-efficacy), reflective motivation (eg, fitness), automatic motivation, social support, and physical opportunity (eg, time). Target group interests, needs, and values in the field of nutrition were translated into target group preferences for app usage, for example, low usage effort, visual feedback, or recipes. Education, training, incentives, persuasion, and enablement were identified as relevant intervention functions. Together with the target group preferences, these were translated via 14 BCTs, such as rewards, graded tasks, or self-monitoring into the app concept Challenge to go (C2go). The expert evaluation suggested changes of some app features for improving adherence, positive health effects, and technical feasibility. The C2go concept comprises 3 worlds: the (1) drinking, (2) vegetable, and (3) fruit worlds. In each world, the users are faced with challenges including feedback and a quiz. Tips were developed based on the health action process approach and to help users gain challenges and, thereby, achieve the target behavior. Challenges can be played alone or against someone in the community. Due to different activities, points can be collected, and levels can be achieved. Collected points open access to an Infothek (information section), where users can choose content that interests them. An avatar guides user through the app.

Conclusions

C2go is aimed at adolescents and young adults and aims to improve their fruit and vegetable consumption as well as drinking habits. It is a theory-driven and target group–adapted dietary mobile intervention concept that uses gamification and was systematically developed using the BCW.

The effect of using a mobile application ("WhiteTeeth") on improving oral hygiene: A randomized controlled trial

Objective

To evaluate the effectiveness of the WhiteTeeth mobile app, a theory‐based mobile health (mHealth) program for promoting oral hygiene in adolescent orthodontic patients.

Methods

In this parallel randomized controlled trial, the data of 132 adolescents were collected during three orthodontic check‐ups: at baseline (T0), at 6‐week follow‐up (T1) and at 12‐week follow‐up (T2). The intervention group was given access to the WhiteTeeth app in addition to usual care (n = 67). The control group received usual care only (n = 65). The oral hygiene outcomes were the presence and the amount of dental plaque (Al‐Anezi and Harradine plaque index), and the total number of sites with gingival bleeding (Bleeding on Marginal Probing Index). Oral health behaviour and its psychosocial factors were measured through a digital questionnaire. We performed linear mixed‐model analyses to determine the intervention effects.

Results

At 6‐week follow‐up, the intervention led to a significant decrease in gingival bleeding (B = −3.74; 95% CI −6.84 to −0.65) and an increase in the use of fluoride mouth rinse (B = 1.93; 95% CI 0.36 to 3.50). At 12‐week follow‐up, dental plaque accumulation (B = −11.32; 95% CI −20.57 to −2.07) and the number of sites covered with plaque (B = −6.77; 95% CI −11.67 to −1.87) had been reduced significantly more in the intervention group than in the control group.

Conclusions

The results show that adolescents with fixed orthodontic appliances can be helped to improve their oral hygiene when usual care is combined with a mobile app that provides oral health education and automatic coaching. Netherlands Trial Registry Identifier: NTR6206: 20 February 2017.

Psychometric validation of the Persian Bergen Social Media Addiction Scale using classic test theory and Rasch models

Background and aims The Bergen Social Media Addiction Scale (BSMAS), a six-item self-report scale that is a brief and effective psychometric instrument for assessing at-risk social media addiction on the Internet. However, its psychometric properties in Persian have never been examined and no studies have applied Rasch analysis for the psychometric testing. This study aimed to verify the construct validity of the Persian BSMAS using confirmatory factor analysis (CFA) and Rasch models among 2,676 Iranian adolescents. Methods In addition to construct validity, measurement invariance in CFA and differential item functioning (DIF) in Rasch analysis across gender were tested for in the Persian BSMAS. Results Both CFA [comparative fit index (CFI) = 0.993; Tucker-Lewis index (TLI) = 0.989; root mean square error of approximation (RMSEA) = 0.057; standardized root mean square residual (SRMR) = 0.039] and Rasch (infit MnSq = 0.88-1.28; outfit MnSq = 0.86-1.22) confirmed the unidimensionality of the BSMAS. Moreover, measurement invariance was supported in multigroup CFA including metric invariance (ΔCFI = -0.001; ΔSRMR = 0.003; ΔRMSEA = -0.005) and scalar invariance (ΔCFI = -0.002; ΔSRMR = 0.005; ΔRMSEA = 0.001) across gender. No item displayed DIF (DIF contrast = -0.48 to 0.24) in Rasch across gender. Conclusions Given the Persian BSMAS was unidimensional, it is concluded that the instrument can be used to assess how an adolescent is addicted to social media on the Internet. Moreover, users of the instrument may comfortably compare the sum scores of the BSMAS across gender.

Dietary planning, self-efficacy, and outcome expectancies play a role in an online intervention on fruit and vegetable consumption

OBJECTIVE

An online intervention to improve fruit and vegetable (FV) intake examines the role of planning, outcome expectancies, self-efficacy and gender. Women are not only expected to eat more FV than men, but they are also expected to be more responsive to nutritional advice and benefit more from treatment.

METHOD

A two-arm digital intervention with 269 men and 395 women (M_age = 41.2, SD_age = 11.45; range: 19-66 years) was conducted in Italy, Spain and Greece, followed up at three and six months, comparing a static with a dynamic, feedback-intensive platform.

RESULTS

Linear mixed models yielded an increase in FV consumption in both the dynamic and the static intervention arms. In men, outcome expectancies were positively related to follow-up FV intake. Dietary planning interacted with self-efficacy on behavioural outcomes.

CONCLUSION

FV intake increased overall, and being a woman and involvement in planning facilitated behaviour change. Women seemed to be more engaged in the dynamic platform resulting in a higher amount of planning. Initial motivation, as indicated by outcome expectancies, seemed to be beneficial for men. Self-efficacious individuals benefitted from their engagement in planning, but self-efficacy did not compensate for failing to plan.