Overweight and obesity in Australia: the 1999-2000 Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

Objective:
To measure the prevalence of obesity in Australian adults and to examine the associations of obesity with socioeconomic and lifestyle factors.

Design:
AusDiab, a cross-sectional study conducted between May 1999 and December 2000, involved participants from 42 randomly selected districts throughout Australia.

Participants:
Of 20 347 eligible people aged > 25 years who completed a household interview, 11 247 attended the physical examination at local survey sites (response rate, 55%).

Main outcome measures:
Overweight and obesity defined by body mass index (BMI; kg/m2) and waist circumference (cm); sociodemographic factors (including smoking, physical activity and television viewing time).

Results:
The prevalence of overweight and obesity (BMI > 25.0 kg/m2; waist circumference > 80.0 cm [women] or > 94.0 cm [men]) in both sexes was almost 60%, defined by either BMI or waist circumference. The prevalence of obesity was 2.5 times higher than in 1980. Using waist circumference, the prevalence of obesity was higher in women than men (34.1% v 26.8%; P < 0.01). Lower educational status, higher television viewing time and lower physical activity time were each strongly associated with obesity, with television viewing time showing a stronger relationship than physical activity time.

Conclusions:
The prevalence of obesity in Australia has more than doubled in the past 20 years. Strong positive associations between obesity and each of television viewing time and lower physical activity time confirm the influence of sedentary lifestyles on obesity, and underline the potential benefits of reducing sedentary behaviour, as well as increasing physical activity, to curb the obesity epidemic.

Projected socioeconomic disparities in the prevalence of obesity among Australian adults

Objective: To project prevalence of normal weight, overweight and obesity by educational attainment, assuming a continuation of the observed individual weight change in the 5-year follow-up of the national population survey, the Australian Diabetes, Obesity and Lifestyle study (AusDiab; 2000–2005).

Methods: Age-specific transition probabilities between BMI categories, estimated using logistic regression, were entered into education-level-specific, incidence-based, multi-state life tables. Assuming a continuation of the weight change observed in AusDiab, these life tables estimate the prevalence of normal weight, overweight and obesity for Australian adults with low (secondary), medium (diploma) and high (degree) levels of education between 2005 and 2025.

Results: The prevalence of obesity among individuals with secondary level educational attainment is estimated to increase from 23% in 2000 to 44% in 2025. Among individuals with a degree qualification or higher, it will increase from 14% to 30%. If all current educational inequalities in weight change could be eliminated, the projected difference in the prevalence of obesity by 2025 between the highest and lowest educated categories would only be reduced by half (to a 6 percentage point difference from 14 percentage points).

Conclusion: We predict that almost half of Australian adults with low educational status will be obese by 2025. Current trends in obesity have the potential to drive an increase in the absolute difference in obesity prevalence between educational categories in future years.

Implications: Unless obesity prevention and management strategies focus specifically on narrowing social inequalities in obesity, inequalities in health are likely to widen.

Inequalities in cardiovascular disease mortality : the role of behavioural, physiological and social risk factors

Background While the relationship between socio-economic disadvantage and cardiovascular disease (CVD) is well established, the role that traditional cardiovascular risk factors play in this association remains unclear. The authors examined the association between education attainment and CVD mortality and the extent to which behavioural, social and physiological factors explained this relationship.

Methods Adults (n=38 355) aged 40–69 years living in Melbourne, Australia were recruited in 1990–1994. Subjects with baseline CVD risk factor data ascertained through questionnaire and physical measurement were followed for an average of 9.4 years with CVD deaths verified by review of medical records and autopsy reports.

Results CVD mortality was higher for those with primary education only, compared with those who had completed tertiary education, with an HR of 1.66 (95% CI 1.10 to 2.49) after adjustment for age, country of birth and gender. Those from the lowest educated group had a more adverse cardiovascular risk factor profile compared with the highest educated group, and adjustment for these risk factors reduced the HR to 1.18 (95% CI 0.78 to 1.77). In analysis of individual risk factors, smoking and waist circumference explained most of the difference in CVD mortality between the highest and lowest education groups.

Conclusions Most of the excess CVD mortality in lower socio-economic groups can be explained by known risk factors, particularly smoking and overweight. While targeting cardiovascular risk factors should not divert efforts from addressing the underlying determinants of health inequalities, it is essential that known risk factors are addressed effectively among lower socio-economic groups.

Reliable and valid NEWS for Chinese seniors : measuring perceived neighborhood attributes related to walking

Background : The effects of the built environment on walking in seniors have not been studied in an Asian context. To examine these effects, valid and reliable measures are needed. The aim of this study was to develop and validate a questionnaire of perceived neighborhood characteristics related to walking appropriate for Chinese seniors (Neighborhood Environment Walkability Scale for Chinese Seniors, NEWS-CS). It was based on the Neighborhood Environment Walkability Scale - Abbreviated (NEWS-A), a validated measure of perceived built environment developed in the USA for adults. A secondary study aim was to establish the generalizability of the NEWS-A to an Asian high-density urban context and a different age group.

Methods : A multidisciplinary panel of experts adapted the original NEWS-A to reflect the built environment of Hong Kong and needs of seniors. The translated instrument was pre-tested on a sample of 50 Chinese-speaking senior residents (65+ years). The final version of the NEWS-CS was interviewer-administered to 484 seniors residing in four selected Hong Kong districts varying in walkability and socio-economic status. Ninety-two participants completed the questionnaire on two separate occasions, 2-3 weeks apart. Test-rest reliability indices were estimated for each item and subscale of the NEWS-CS. Confirmatory factor analysis was used to develop the measurement model of the NEWS-CS and cross-validate that of the NEWS-A.

Results : The final version of the NEWS-CS consisted of 14 subscales and four single items (76 items). Test-retest reliability was moderate to good (ICC > 50 or % agreement > 60) except for four items measuring distance to destinations. The originally-proposed measurement models of the NEWS-A and NEWS-CS required 2-3 theoretically-justifiable modifications to fit the data well.

Conclusions : The NEWS-CS possesses sufficient levels of reliability and factorial validity to be used for measuring perceived neighborhood environment in Chinese seniors. Further work is needed to assess its construct validity and generalizability to other Asian locations. In general, the measurement model of the original NEWS-A was generalizable to this study context, supporting the feasibility of cross-country and age-group comparisons of the effect of the neighborhood environment on walking using the NEWS-A as a tool to measure the perceived built environment.

The mediating role of dietary factors and leisure time physical activity on socioeconomic inequalities in body mass index among Australian adults

BACKGROUND: The relationship between socioeconomic position and obesity has been clearly established, however, the extent to which specific behavioural factors mediate this relationship is less clear. This study aimed to ascertain the contribution of specific dietary elements and leisure-time physical activity (LTPA) to variations in obesity with education in the baseline (1990-1994) Melbourne Collaborative Cohort Study (MCCS).

METHODS: 18, 489 women and 12, 141 men were included in this cross-sectional analysis. A series of linear regression models were used in accordance with the products of coefficients method to examine the mediating role of alcohol, soft drink (regular and diet), snacks (healthy and sweet), savoury items (healthy and unhealthy), meeting fruit and vegetable guidelines and LTPA on the relationship between education and body mass index (BMI).

RESULTS: Compared to those with lowest educational attainment, those with the highest educational attainment had a 1 kg/m2 lower BMI. Among men and women, 27% and 48%, respectively, of this disparity was attributable to differences in LTPA and diet. Unhealthy savoury item consumption and LTPA contributed most to the mediated effects for men and women. Alcohol and diet soft drink were additionally important mediators for women.

CONCLUSIONS: Diet and LTPA are potentially modifiable behavioural risk factors for the development of obesity that contribute substantially to inequalities in BMI. Our findings highlight the importance of specific behaviours which may be useful to the implementation of effective, targeted public policy to reduce socioeconomic inequalities in obesity.

The relation between non-occupational physical activity and years lived with and without disability

OBJECTIVES: The effects of non-occupational physical activity were assessed on the number of years lived with and without disability between age 50 and 80 years. METHODS: Using the GLOBE study and the Longitudinal Study of Aging, multi-state life tables were constructed yielding the number of years with and without disability between age 50 and 80 years. To obtain life tables by level of physical activity (low, moderate, high), hazard ratios were derived for different physical activity levels per transition (non-disabled to disabled, non-disabled to death, disabled to non-disabled, disabled to death) adjusted for age, sex and confounders. RESULTS: Moderate, compared to low non-occupational physical activity reduced incidence of disability (HR 0.66, 95% CI 0.51 to 0.86), increased recovery (HR 1.95, 95% CI 1.32 to 2.87), and represents a gain of disability-free years and a loss of years with disability (male 3.1 and 1.2; female 4.0 and 2.8 years). Performing high levels of non-occupational physical activity further reduced incidence, and showed a higher gain in disability-free years (male 4.1; female 4.7), but a similar reduction in years with disability. CONCLUSION: Among 50-80-year-olds promoting physical activity is a fundamental factor to achieve healthy ageing.

Effects of a free school breakfast programme on school attendance, achievement, psychosocial function, and nutrition: a stepped wedge cluster randomised trial

BACKGROUND: Approximately 55,000 children in New Zealand do not eat breakfast on any given day. Regular breakfast skipping has been associated with poor diets, higher body mass index, and adverse effects on children's behaviour and academic performance. Research suggests that regular breakfast consumption can improve academic performance, nutrition and behaviour. This paper describes the protocol for a stepped wedge cluster randomised trial of a free school breakfast programme. The aim of the trial is to determine the effects of the breakfast intervention on school attendance, achievement, psychosocial function, dietary habits and food security.

METHODS/DESIGN: Sixteen primary schools in the North Island of New Zealand will be randomised in a sequential stepped wedge design to a free before-school breakfast programme consisting of non-sugar coated breakfast cereal, milk products, and/or toast and spreads. Four hundred children aged 5-13 years (approximately 25 per school) will be recruited. Data collection will be undertaken once each school term over the 2010 school year (February to December). The primary trial outcome is school attendance, defined as the proportion of students achieving an attendance rate of 95% or higher. Secondary outcomes are academic achievement (literacy, numeracy, self-reported grades), sense of belonging at school, psychosocial function, dietary habits, and food security. A concurrent process evaluation seeks information on parents', schools' and providers' perspectives of the breakfast programme.

DISCUSSION: This randomised controlled trial will provide robust evidence of the effects of a school breakfast programme on students' attendance, achievement and nutrition. Furthermore the study provides an excellent example of the feasibility and value of the stepped wedge trial design in evaluating pragmatic public health intervention programmes.

Workplace pedometer interventions for increasing physical activity

Background
The World Health Organization and the World Economic Forum have recommended further research to strengthen current knowledge of workplace health programmes, particularly on effectiveness and using simple instruments. A pedometer is one such simple instrument that can be incorporated in workplace interventions.

Objectives
To assess the effectiveness of pedometer interventions in the workplace for increasing physical activity and improving subsequent health outcomes.

Search methods
Electronic searches of the Cochrane Central Register of Controlled Trials (671 potential papers), MEDLINE (1001), Embase (965), CINAHL (1262), OSH UPDATE databases (75) and Web of Science (1154) from the earliest record to between 30th January and 6th February 2012 yielded 3248 unique records. Reference lists of articles yielded an additional 34 papers. Contact with individuals and organisations did not produce any further records.

Selection criteria
We included individual and cluster-randomised controlled trials of workplace health promotion interventions with a pedometer component in employed adults. The primary outcome was physical activity and was part of the eligibility criteria. We considered subsequent health outcomes, including adverse effects, as secondary outcomes.

Data collection and analysis
Two review authors undertook the screening of titles and abstracts and the full-text papers independently. Two review authors (RFP and MC) independently completed data extraction and risk of bias assessment. We contacted authors to obtain additional data and clarification.

Main results
We found four relevant studies providing data for 1809 employees, 60% of whom were allocated to the intervention group. All studies assessed outcomes immediately after the intervention had finished and the intervention duration varied between three to six months. All studies had usual treatment control conditions; however one study’s usual treatment was an alternative physical activity programme while the other three had minimally active controls. In general, there was high risk of bias mainly due to lack of blinding, self reported outcome measurement, incomplete outcome data due to attrition, and most of the studies had not published protocols, which increases the likelihood of selective reporting.

Three studies compared the pedometer programme to a minimally active control group, but the results for physical activity could not be combined because each study used a different measure of activity. One study observed an increase in physical activity under a pedometer programme, but the other two did not find a significant difference. For secondary outcomes we found improvements in body mass index, waist circumference, fasting plasma glucose, the quality of life mental component and worksite injury associated with the pedometer programmes, but these results were based on limited data from one or two small studies. There were no differences between the pedometer programme and the control group for blood pressure, a number of biochemical outcomes and the quality of life physical component. Sedentary behaviour and disease risk scores were not measured by any of the included studies.

One study compared a pedometer programme and an alternative physical activity programme, but baseline imbalances made it difficult to distinguish the true improvements associated with either programme.

Overall, there was insufficient evidence to assess the effectiveness of pedometer interventions in the workplace.

There is a need for more high quality randomised controlled trials to assess the effectiveness of pedometer interventions in the workplace for increasing physical activity and improving subsequent health outcomes. To improve the quality of the evidence available, future studies should be registered in an online trials register, publish a protocol, allocate time and financial support to reducing attrition, and try to blind personnel (especially those who undertake measurement). To better identify the effects of pedometer interventions, future studies should report a core set of outcomes (total physical activity in METs, total time sitting in hours and minutes, objectively measured cardiovascular disease and type II diabetes risk factors, quality of life and injury), assess outcomes in the long term and undertake subgroup analyses based upon demographic subgroups (e.g. age, gender, educational status). Future studies should also compare different types of active intervention to test specific intervention components (eligibility, duration, step goal, step diary, settings), and settings (occupation, intervention provider).

Authors’ conclusions
There was limited and low quality data providing insufficient evidence to assess the effectiveness of pedometer interventions in the workplace for increasing physical activity and improving subsequent health outcomes.

P L A I N  L A N G U A G E  S U M M A R Y

Do workplace pedometer interventions increase physical activity?
The World Health Organization recommends that most people should undertake at least 30 minutes of moderate-intensity physical activity on most days, as it reduces the risk of cardiovascular disease, diabetes and some cancers. However, less than 40% of the world’s population are undertaking adequate amounts of physical activity and rates have been declining. Here we assess whether pedometer workplace interventions increase physical activity and thereby lead to subsequent health benefits.

To assess this, we searched for randomised controlled trials of workplace health promotion interventions that involved the use of a pedometer undertaken in employed adults. Between 30th January and 6th February 2012 we searched a range of electronic libraries and references of relevant papers, retrieving 3282 potential papers.

We eventually included four studies in the review. One study compared pedometer programmes with an alternative physical activity programme, but there were important baseline differences between the intervention and control groups that made it difficult to distinguish the true effect. The three remaining studies compared pedometer programmes with minimally active control groups. One study observed an improvement in physical activity in the pedometer programme, but two other studies found no significant difference between the pedometer group and the control group. We could not combine these results together, as each study used a different measure for physical activity, so it is not clear what the overall effect is. Single studies found beneficial changes in body mass index, fasting plasma glucose, the mental component of quality of life and worksite injury associated with the pedometer programmes as opposed to the control group. However, none of the studies identified consistent differences between the pedometer programme and the control group for waist circumference, blood pressure and quality of life outcomes. In addition, we judged the majority of included studies to have a high risk of bias, mainly due to participants and staff knowing who was in the intervention and who was in the control group, attrition of participants and not having published a protocol prior to running the study.

We conclude that there was insufficient evidence to assess whether workplace pedometer interventions are of benefit. There is a need for further high quality randomised controlled trials to be undertaken with a range of health outcomes and assessment in the long term.

Emotional intelligence and teacher self efficacy : the contribution of teacher status and length of experience

Practicing teachers and principals in selected Government schools in Victoria provided data on their levels of emotional intelligence and teacher efficacy beliefs. The data supported the theoretical expectation of a linkage between emotional intelligence and teacher self efficacy. Regression analyses showed that neither gender nor age moderated this relationship. However length of teaching experience and current status add significant direct effects on predicting teacher self efficacy but did not moderate the relationship between emotional intelligence and teacher self efficacy. These findings are significant as this now demonstrates a relationship between levels of emotional intelligence in teachers, their self efficacy beliefs and teacher effectiveness.

How socio-economic status contributes to participation in leisure-time physical activity

The aim of this cross-sectional study was to identify individual, social, and environmental contributors (mediators) to individual- and area-level differences in leisure-time physical activity across socio-economic groups. A two-stage stratified sampling design was used to recruit 20–65 year old adults (N = 2194) living in 154 census collection districts of Adelaide, Australia (overall response rate: 12%). Participants completed two surveys six months apart (response rate on the second survey: 83%). Individual-level socio-economic status (SES) was assessed using self-report measures on educational attainment, household income, and household size. Area-level SES was assessed using census data on median household income and household size for each selected census district. Bootstrap generalized linear models were used to examine associations between SES, potential mediators, and leisure-time physical activity. The product-of-coefficient test was used to estimate mediating effects. All SES measures were independently associated with potential individual and social mediators of the SES-activity relationships. Individual- and area-level income was also associated with perceived neighborhood attributes. Self-efficacy and social support for physical activity explained virtually all of the differences in physical activity across educational attainment groups. Physical barriers to walking and access to public open space contributed in part to the explanation of differences in recreational walking across income groups. Yet, self-efficacy and social support were the key mediators of the observed relationships between individual- and area-level income and physical activity. This study suggests that in order to increase physical activity participation in the more disadvantaged segments of the population, comprehensive, multilevel interventions targeting activity-related attitudes and skills as well as social and physical environments are needed.

Understanding educational process in leadership development

This thesis is a case study of educational process in the leadership development program of the Australian Defence Force Academy. The intention is to determine the relative emphasis in educational process on the conventional command and managerial compliance (Type A) style and the emergent contingent and creative (Type B) style of leadership. The Type A style is theorised as emphasizing hierarchy and control, whereas the emphasis in a Type B style is on adaptive and entrepreneurial behaviour. This study looks at the learning process in a cultural and structural context rather than focus on curriculum and instructional design. Research in this wider context is intended to enable development processes to successfully bridge a gap between theory and practice, implicit in studies that identify theories 'in-operation' as different from the theories 'espoused' (Argyris 1992, Savage 1996). In terms of espoused and in-use theory, the study seeks to produce a valid and reliable result to the question: what is the relative emphasis on the two leadership styles in the operation of the three educational mechanisms of curriculum, pedagogy (teaching practice) and assessment? The quantitative analysis of results (n = 114) draws attention to both leadership styles in terms of two and three-way relationships of style, cadet or work group and service type. The data shows that both Type A and Type B leadership styles are evident in the general conversation of the organisation. This trend is present as espoused theory in the curriculum of the Defence Academy. However, the data also confirm a clear and strong emphasis towards command and managerial compliance as theory-in-use, particularly by cadets. This emphasis is noticeably evident in the teaching and assessment practice of the Defence Academy. Other research outcomes include the observation that: Contextually, while studies show it is difficult to isolate skills from their cultural and biographical context (Watkins, 1991:15), this study suggests that it is equally difficult to isolate skills development from this context. There is a strong task or instrumental link identified by cadet responses in terms of content and development process at the Defence Academy, in contrast to the wider developmental emphasis in general literature and senior officer interviews. There is a lack of awareness of teaching strategies and development activity consistent with espoused Type B leadership theory and curriculum content. This gap is compounded by the use in the Defence Academy of personnel without teaching expertise or suitable developmental experience. The socialisation of cadets into the military workplace is the primary purpose of training. This purpose appears taken for granted by all concerned - staff, cadets and senior officers. Defence Academy development processes appear to be faced with a dilemma. Arguably, training and learning from experience are limited approaches to development. Training, which involves learning by replication, and learning from experience, which is largely imitative, are both of little use when people are faced with novel and ambiguous situations. This study suggests that in order to support the development of capabilities that go beyond training based competence a learning and development approach is needed. This more expansive approach requires educational planners to consider the cultural and social context that can inadvertently promote the status quo in practice over espoused outcomes.

The impression that I get : educational inclusion explored through the voices of young people with vision impairment

Despite the notion of educational inclusion of students with disabilities increasing in popularity, the day-to-day reality of its effectiveness remains mostly unknown. This paper reports key findings of a small-scale qualitative study that was conducted with a group of young people with vision impairment who attended an inclusive secondary school. The aim of the research was to ascertain their voiced experiences of their inclusion. Relevant to the study was the researcher’s insider status, which allowed for his unique insight and shared experiences with participants to influence data collection and analysis. The students reported a constant trade off that occurred between their aspirations for access and autonomy and practices of other stakeholders in the school that both facilitated and inhibited their inclusion. In sum, the students’ inclusion was ineffective because of habitual inhibiting actions of others. Recommendations are made based on Slee’s (2001) call for altered teaching and learning realities to promote educational inclusion, and a model of social justice that could bring about increased student agency (Higgins, Macarthur & Kelly, 2009).

Socioeconomic status, neighborhood characteristics, and walking within the neighborhood among older Hong Kong Chinese

Objective: 

The relationship between engineering bachelor qualifications and occupational status in Australia

Internationally, the importance of science, technology, engineering and mathematics (STEM) for innovation and competition drives concerns about the adequacy of national STEM workforces. Data from the UK, USA and Australia suggest that, even immediately post-graduation, a significant proportion of engineering bachelor graduates do not work in engineering roles. Using the 2011 Australian census data, we present an investigation into the relationship between educational qualifications and occupational status of Australian engineering bachelor graduates, and how this status varies specifically with graduate age. We consider the implications of these findings and present recommendations for the recruitment and education of Australian engineering undergraduates. We conclude that engineering students would be better informed about, and equipped for, the world of post-graduation work if they were exposed to the likely options for their career trajectory. Likewise, secondary school students and others considering engineering undergraduate study would be more honestly advised if they were informed about the full range of career possibilities for engineering graduates and the probability that they are just as likely to work out of engineering as in it.