Using repeatability to study physiological and behavioural traits: ignore time-related change at your peril

© 2015 The Association for the Study of Animal Behaviour. Broad sense repeatability, which refers to the extent to which individual differences in trait scores are maintained over time, is of increasing interest to researchers studying behavioural or physiological traits. Broad sense repeatability is most often inferred from the statistic R (the intraclass correlation, or narrow sense repeatability). However, R ignores change over time, despite the inherent longitudinal nature of the data (repeated measures over time). Here, we begin by showing that most studies ignore time-related change when estimating broad sense repeatability, and estimate R with low statistical power. Given this problem, we (1) outline how and why ignoring time-related change in scores (that occurs for whatever reason) can seriously affect estimates of the broad sense repeatability of behavioural or physiological traits, (2) discuss conditions in which various indices of R can or cannot provide reliable estimates of broad sense repeatability, and (3) provide suggestions for experimental designs for future studies. Finally, given that we already have abundant evidence that many labile traits are 'repeatable' in that broad sense (i.e. R>. 0), we suggest a shift in focus towards obtaining robust estimates of the repeatability of behavioural and physiological traits. Given how labile these traits are, this will require greater experimental (and/or statistical) control and larger sample sizes in order to detect and quantify change over time (if present).

A web-based, social networking physical activity intervention for insufficiently active adults delivered via Facebook app: randomized controlled trial

BACKGROUND: Online social networks offer considerable potential for delivery of socially influential health behavior change interventions. OBJECTIVE: To determine the efficacy, engagement, and feasibility of an online social networking physical activity intervention with pedometers delivered via Facebook app. METHODS: A total of 110 adults with a mean age of 35.6 years (SD 12.4) were recruited online in teams of 3 to 8 friends. Teams were randomly allocated to receive access to a 50-day online social networking physical activity intervention which included self-monitoring, social elements, and pedometers ("Active Team" Facebook app; n=51 individuals, 12 teams) or a wait-listed control condition (n=59 individuals, 13 teams). Assessments were undertaken online at baseline, 8 weeks, and 20 weeks. The primary outcome measure was self-reported weekly moderate-to-vigorous physical activity (MVPA). Secondary outcomes were weekly walking, vigorous physical activity time, moderate physical activity time, overall quality of life, and mental health quality of life. Analyses were undertaken using random-effects mixed modeling, accounting for potential clustering at the team level. Usage statistics were reported descriptively to determine engagement and feasibility. RESULTS: At the 8-week follow-up, the intervention participants had significantly increased their total weekly MVPA by 135 minutes relative to the control group (P=.03), due primarily to increases in walking time (155 min/week increase relative to controls, P<.001). However, statistical differences between groups for total weekly MVPA and walking time were lost at the 20-week follow-up. There were no significant changes in vigorous physical activity, nor overall quality of life or mental health quality of life at either time point. High levels of engagement with the intervention, and particularly the self-monitoring features, were observed. CONCLUSIONS: An online, social networking physical activity intervention with pedometers can produce sizable short-term physical activity changes. Future work is needed to determine how to maintain behavior change in the longer term, how to reach at-need populations, and how to disseminate such interventions on a mass scale. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614000488606; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366239 (Archived by WebCite at http://www.webcitation.org/6ZVtu6TMz).

The impact of perceived corporate social responsibility on organizational commitment and the moderating role of collectivism and masculinity: evidence from China

This study examines the relationship between employee perceptions of corporate social responsibility practices and their organizational commitment. Hierarchical regression analysis was utilized to analyze survey data on 280 employees from five export-oriented manufacturing firms in China. Employee perceptions of corporate social responsibility practices towards internal stakeholders were found to relate positively to their organizational commitment. In contrast, employee perceptions of corporate social responsibility practices to external stakeholders had a nonsignificant or marginally significant impact on organizational commitment. In addition, the collectivism and masculinity orientations of employees were found to moderate this relationship. These findings provide an insight into how corporate social responsibility practices may be utilized to motivate diverse groups of employees within China-based organizations. © 2013 Taylor & Francis.

Self-regulated learning strategies & academic achievement in online higher education learning environments: a systematic review

© 2015 Elsevier Inc. All rights reserved. As enrolments in online courses continue to increase, there is a need to understand how students can best apply self-regulated learning strategies to achieve academic success within the online environment. A search of relevant databases was conducted in December 2014 for studies published from 2004 to Dec 2014 examining SRL strategies as correlates of academic achievement in online higher education settings. From 12 studies, the strategies of time management, metacognition, effort regulation, and critical thinking were positively correlated with academic outcomes, whereas rehearsal, elaboration, and organisation had the least empirical support. Peer learning had a moderate positive effect, however its confidence intervals crossed zero. Although the contributors to achievement in traditional face-to-face settings appear to generalise to on-line context, these effects appear weaker and suggest that (1) they may be less effective, and (2) that other, currently unexplored factors may be more important in on-line contexts.

Nutritional management of gastrointestinal surgical patients in Victoria's public hospitals

Aim: Poor nutritional status has negative effects on post-operative outcomes, further compounded by surgical stress and fasting, places gastrointestinal surgery patients at high risk of malnutrition. Recent published research has challenged historic surgical nutrition practices; however, changes to practice in Australia have been slow. The aim of this study was to investigate current nutritional management of gastrointestinal surgery patients and compare this with the best practice guidelines, while exploring enablers to implementation of best practice. Methods: A 30-question telephone survey was developed to explore demographics and nutritional management of gastrointestinal surgical patients during pre-admission, inpatient stay and post-operative care. Forty-one gastrointestinal surgery dietitians were identified and contacted from 31 public hospitals in Victoria, Australia, and invited to participate. Results: Twenty-five dietitians participated in the survey (response rate 61%). Very few dietitians (12%) were funded for pre-admission clinics or outpatient clinics, and, overwhelmingly, dietitians reported not being involved in nutritional decision-making, and reported feeling unsatisfied with current nutritional management of patients. Despite half the hospitals reporting following best practice guidelines, only 22% implemented guidelines completely. There was no correlation observed between dietitian experience, department size or full-time equivalents allocated to surgery and nutritional intervention; however, the presence of a care pathway made a significant difference to the dietitian's overall satisfaction with dietetic care (P = 0.002). Conclusions: Current nutritional management of gastrointestinal surgery patients in Victorian hospitals is far from best practice. The implementation of a care pathway is the most effective way of ensuring best practice nutritional management of gastrointestinal surgical patients.

Patients presenting with fractures are likely to be vitamin D deficient: are we getting enough sun?

BACKGROUND: 25-Hydroxyvitamin D serves a crucial role in bone metabolism through its role on osteoclast and osteoblastic function. To assess the implication of vitamin D and its relationship to bone fracture and fracture force, we have examined vitamin D levels in patients requiring inpatient fracture management. METHODS: We performed serological testing of vitamin D levels, calcium, parathyroid hormone and liver function tests on patients admitted to our rural institution in southeastern Australia for inpatient fracture management. All participants completed a questionnaire designed to screen for potential contributing factors to bony fragility. Demographic data were also obtained including age, gender and body mass index. Fracture location and the type of inpatient management as well as the force of injury were included in our analysis. RESULTS: We recruited 100 patients to the study, with a median age of 72 (range 22-98) of whom 66 were women. Most had low-energy fractures (79%), treated by internal fixation (73%) or arthroplasty (9%) with 18 treated non-operatively. The majority of the patients were at best vitamin D insufficient, <75 nmol/L (77%), and 38% were vitamin D deficient (<50 nmol/L). Only 14 patients had a formal diagnosis of osteoporosis at presentation, with 63 patients claiming daily sun exposure in line with recommendations for vitamin D sufficiency. CONCLUSIONS: Our data suggest that the prevalence of vitamin D insufficiency and deficiency is common in patients presenting with fractures in southeastern Australia and is not confined to elderly patients. All patients with fractures should be assessed for vitamin D levels and treated in accordance with vitamin D deficiency guidelines.

The impact of socially responsible human resource management on employees' organizational citizenship behaviour: the mediating role of organizational identification

Based on insights from social exchange and social identity theories, this paper examines the influence of three dimensions of socially responsible human resource management (SR-HRM), namely legal compliance HRM, employee-oriented HRM and general CSR facilitation HRM, on employees' organizational citizenship behaviour (OCB). Structural equation modelling of dyadic data collected from Chinese employees and their direct supervisors in three phases revealed that whilst organizational identification fully mediated the relationship between employee-oriented HRM and employee OCB, general CSR facilitation HRM had a direct effect on employee OCB. In contrast, legal compliance HRM neither influenced employee OCB directly, nor indirectly through organizational identification. The findings highlight the important but complex role played by SR-HRM in eliciting positive employee work outcomes, and contribute to our knowledge of the mechanisms underlying this relationship.

Recommendations for physical activity in older adults

 Older adults find it difficult to meet moderate and vigorous exercise targets. Given that a dose-response exists for physical activity and health benefits, Phillip B Sparling and colleagues argue that a change in message to reduce sedentary time and increase light activities may prove more realistic and pave the way to more intense exercise

Investigating the effects of personality traits on pair programming in a higher education setting through a family of experiments

Evidence from our systematic literature review revealed numerous inconsistencies in findings from the Pair Programming (PP) literature regarding the effects of personality on PP's effectiveness as a pedagogical tool. In particular: i) the effect of differing personality traits of pairs on the successful implementation of pair-programming (PP) within a higher education setting is still unclear, and ii) the personality instrument most often used had been Myers-Briggs Type Indicator (MBTI), despite being an indicator criticized by personality psychologists as unreliable in measuring an individual's personality traits. These issues motivated the research described in this paper. We conducted a series of five formal experiments (one of which was a replicated experiment), between 2009 and 2010, at the University of Auckland, to investigate the effects of personality composition on PP's effectiveness. Each experiment looked at a particular personality trait of the Five-Factor personality framework. This framework comprises five broad traits (Openness to experience, Conscientiousness, Extraversion, Agreeableness, and Neuroticism), and our experiments focused on three of these - Conscientiousness, Neuroticism, and Openness. A total of 594 undergraduate students participated as subjects. Overall, our findings for all five experiments, including the replication, showed that Conscientiousness and Neuroticism did not present a statistically significant effect upon paired students' academic performance. However, Openness played a significant role in differentiating paired students' academic performance. Participants' survey results also indicated that PP not only caused an increase in satisfaction and confidence levels but also brought enjoyment to the tutorial classes and enhanced students' motivation.

Religious ambivalence: suppression of pro-social attitudes toward asylum seekers by right-wing authoritarianism

A survey of 168 White Australian community members examined whether ambivalence toward certain social groups by some religious individuals constituted a suppression effect in which authoritarian motivated prejudice suppressed more pro-social attitudes toward asylum seekers. Using mediation analysis, it was found that Christian religious identity was not significantly associated with prejudice at a bivariate level. However, when Right-Wing Authoritarianism (RWA) was taken into account, Christians (compared with non-Christians) were less likely to hold negative attitudes toward asylum seekers in Australia. Inclusion of acculturation ideologies (assimilation, multiculturalism, and color-blindness) in the models indicated that the suppression effect was specific to RWA rather than due to other intergroup attitudes. However, findings suggest that multiculturalism may be one proximal indicator of Christian pro-sociality.

Improvements in fundamental movement skill competency mediate the effect of the SCORES intervention on physical activity and cardiorespiratory fitness in children

Numerous studies have identified a positive association between fundamental movement skill (FMS) competency and physical activity in children; however, the causal pathways have not been established. The aim of this study is to determine if changes in FMS competency mediated the effect of the Supporting Children's Outcomes using Rewards, Exercise and Skills (SCORES) intervention on physical activity and cardiorespiratory fitness in children. Eight primary schools (25 classes) and 460 children (aged 8.5 ± 0.6, 54% girls) were randomised to the SCORES intervention or control group for the 12-month study. The outcomes were accelerometer-determined moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness. The hypothesised mediators were actual FMS competency and perceived sport competence. Mediation analyses were conducted using multilevel linear analysis in MPlus. From the original sample, 138 (30.0%) and 370 (80.4%) children provided useable physical activity and cardiorespiratory fitness data at post-test assessments. There were significant treatment effects for locomotor skills and overall FMSs. Changes in MVPA were associated with changes in object-control skills, overall FMSs and perceived competence. The overall FMSs had a significant mediating effect on MVPA (AB = 2.09, CI = 0.01-4.55). Overall FMSs (AB = 1.19, CI = 0.002-2.79) and locomotor skills (AB = 0.74, CI = 0.01-1.69) had a significant mediating effect on cardiorespiratory fitness. The results of this study conclude that actual but not perceived movement skill competency mediated the effect of the SCORES intervention on physical activity and cardiorespiratory fitness.

A meta-analysis of trabecular bone score in fracture risk prediction and its relationship to FRAX

Trabecular bone score (TBS) is a grey-level textural index of bone microarchitecture derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images. TBS is a BMD-independent predictor of fracture risk. The objective of this meta-analysis was to determine whether TBS predicted fracture risk independently of FRAX probability and to examine their combined performance by adjusting the FRAX probability for TBS. We utilized individual level data from 17,809 men and women in 14 prospective population-based cohorts. Baseline evaluation included TBS and the FRAX risk variables and outcomes during follow up (mean 6.7 years) comprised major osteoporotic fractures. The association between TBS, FRAX probabilities and the risk of fracture was examined using an extension of the Poisson regression model in each cohort and for each sex and expressed as the gradient of risk (GR; hazard ratio per 1SD change in risk variable in direction of increased risk). FRAX probabilities were adjusted for TBS using an adjustment factor derived from an independent cohort (the Manitoba Bone Density Cohort). Overall, the GR of TBS for major osteoporotic fracture was 1.44 (95% CI: 1.35-1.53) when adjusted for age and time since baseline and was similar in men and women (p > 0.10). When additionally adjusted for FRAX 10-year probability of major osteoporotic fracture, TBS remained a significant, independent predictor for fracture (GR 1.32, 95%CI: 1.24-1.41). The adjustment of FRAX probability for TBS resulted in a small increase in the GR (1.76, 95%CI: 1.65, 1.87 vs. 1.70, 95%CI: 1.60-1.81). A smaller change in GR for hip fracture was observed (FRAX hip fracture probability GR 2.25 vs. 2.22). TBS is a significant predictor of fracture risk independently of FRAX. The findings support the use of TBS as a potential adjustment for FRAX probability, though the impact of the adjustment remains to be determined in the context of clinical assessment guidelines.

The role of social support in protecting mental health when employed and unemployed: a longitudinal fixed-effects analysis using 12 annual waves of the HILDA cohort

Perceived social support is associated with overall better mental health. There is also evidence that unemployed workers with higher social support cope better psychologically than those without such support. However, there has been limited research about the effect of social support among people who have experienced both unemployment and employment. We assessed this topic using 12 years of annually collected cohort data. The sample included 3190 people who had experienced both unemployment and employment. We used longitudinal fixed-effects modelling to investigate within-person changes in mental health comparing the role of social support when a person was unemployed to when they were employed. Compared to when a person reported low social support, a change to medium (6.35, 95% 5.66 to 7.04, p < 0.001) or high social support (11.58, 95%, 95% CI 10.81 to 12.36, p < 0.001) was associated with a large increase in mental health (measured on an 100 point scale, with higher scores representing better mental health). When a person was unemployed but had high levels of social support, their mental health was 2.89 points (95% CI 1.67 to 4.11, p < 0.001) higher than when they were employed but had lower social support. The buffering effect of social support was confirmed in stratified analysis. There was a strong direct effect of social support on mental health. The magnitude of these differences could be considered clinically meaningful. Our results also suggest that social support has a significant buffering effect on mental health when a person is unemployed.

Living healthier for longer: comparative effects of three heart-healthy behaviors on life expectancy with and without cardiovascular disease

BACKGROUND: Non-smoking, having a normal weight and increased levels of physical activity are perhaps the three key factors for preventing cardiovascular disease (CVD). However, the relative effects of these factors on healthy longevity have not been well described. We aimed to calculate and compare the effects of non-smoking, normal weight and physical activity in middle-aged populations on life expectancy with and without cardiovascular disease.

METHODS: Using multi-state life tables and data from the Framingham Heart Study (n = 4634) we calculated the effects of three heart healthy behaviours among populations aged 50 years and over on life expectancy with and without cardiovascular disease. For the life table calculations, we used hazard ratios for 3 transitions (No CVD to CVD, no CVD to death, and CVD to death) by health behaviour category, and adjusted for age, sex, and potential confounders.

RESULTS: High levels of physical activity, never smoking (men), and normal weight were each associated with 20-40% lower risks of developing CVD as compared to low physical activity, current smoking and obesity, respectively. Never smoking and high levels of physical activity reduced the risks of dying in those with and without a history of CVD, but normal weight did not. Never-smoking was associated with the largest gains in total life expectancy (4.3 years, men, 4.1 years, women) and CVD-free life expectancy (3.8 and 3.4 years, respectively). High levels of physical activity and normal weight were associated with lesser gains in total life expectancy (3.5 years, men and 3.4 years, women, and 1.3 years, men and 1.0 year women, respectively), and slightly lesser gains in CVD-free life expectancy (3.0 years, men and 3.1 years, women, and 3.1 years men and 2.9 years women, respectively). Normal weight was the only behaviour associated with a reduction in the number of years lived with CVD (1.8 years, men and 1.9 years, women).

CONCLUSIONS: Achieving high levels of physical activity, normal weight, and never smoking, are effective ways to prevent cardiovascular disease and to extend total life expectancy and the number of years lived free of CVD. Increasing the prevalence of normal weight could further reduce the time spent with CVD in the population.

Bias in peripheral depression biomarkers

BACKGROUND: To aid in the differentiation of individuals with major depressive disorder (MDD) from healthy controls, numerous peripheral biomarkers have been proposed. To date, no comprehensive evaluation of the existence of bias favoring the publication of significant results or inflating effect sizes has been conducted. METHODS: Here, we performed a comprehensive review of meta-analyses of peripheral nongenetic biomarkers that could discriminate individuals with MDD from nondepressed controls. PubMed/MEDLINE, EMBASE, and PsycINFO databases were searched through April 10, 2015. RESULTS: From 15 references, we obtained 31 eligible meta-analyses evaluating biomarkers in MDD (21,201 cases and 78,363 controls). Twenty meta-analyses reported statistically significant effect size estimates. Heterogeneity was high (I2 ≥ 50%) in 29 meta-analyses. We plausibly assumed that the true effect size for a meta-analysis would equal the one of its largest study. A significant summary effect size estimate was observed for 20 biomarkers. We observed an excess of statistically significant studies in 21 meta-analyses. The summary effect size of the meta-analysis was higher than the effect of its largest study in 25 meta-analyses, while 11 meta-analyses had evidence of small-study effects. CONCLUSIONS: Our findings suggest that there is an excess of studies with statistically significant results in the literature of peripheral biomarkers for MDD. The selective publication of 'positive studies' and the selective reporting of outcomes are possible mechanisms. Effect size estimates of meta-analyses may be inflated in this literature.