Patterns and demographic predictors of 5-year weight change in a multi-ethnic cohort of men and women in Australia

Objective: This study investigated 5-year trends in body weight, overweight and obesity and their association with sociodemographic variables in a large, multi-ethnic community sample of Australian adults.  Design: This prospective population study used baseline and 5-year follow-up data from participants in the Melbourne Collaborative Cohort Study (MCCS). Setting: Population study in Melbourne, Australia. Subjects: In total, 12 125 men and 17 674 women aged 35–69 years at baseline. Results: Mean 5-year weight change in this sample was +1.58 (standard deviation (SD) 4.82) kg for men and +2.42 (SD 5.17) kg for women. Younger (35–44 years) men and, in particular, women gained more weight than older adults and were at highest risk of major weight gain ($5 kg) and becoming overweight. Risk of major weight gain and associations between demographic variables and weight change did not vary greatly by ethnicity. Education level showed complex associations with weight outcomes that differed by sex and ethnicity. Multivariate analyses showed that, among men, higher initial body weight was associated with decreased likelihood of major weight gain, whereas among women, those initially overweight or obese were about 20% more likely to experience major weight gain than underweight or healthy weight women. Conclusions: Findings of widespread weight gain across this entire population sample, and particularly among younger women and women who were already overweight, are a cause for alarm. The prevention of weight gain and obesity across the entire population should be an urgent public health priority. Young-to-mid adulthood appears to be a critical time to intervene to prevent future weight gain.

Adapting to market conditions : plagiarism, cheating and strategies for cohort customisation

This paper commences with themes discussed in two papers, “An
assessment strategy to help forestall plagiarism problems” (Kennedy,
2004) concerning how assessment strategies can be structured to
minimise plagiarism and “Paradigm shift: From traditional to on-line
education” (Gallie & Joubert, 2004) concerning the shifting focus
between teacher-centred and student-centred learning. The themes
raised are examined from the perspective of post-graduate course
delivery to predominantly international students within the context of
recognition of the specific needs of the student body. The themes are
then extended by considering the outcomes of a case study that
adapted methods of assessment with a view to improving outcomes
and reducing plagiarism and cheating.

Comparability of dietary patterns assessed by multiple dietary assessment methods: results from the 1946 British Cohort

Objective: The aim of this study is to evaluate the consistency of dietary patterns assessed through the use of a dietary recall and a 5-day food diary. Design: Participants (n=2265) of a longitudinal study of health and development completed 48-h dietary recall at interview, followed by a 5-day food diary and with the 24 h immediately preceding the interview analysed separately as a 24-h recall. Mean intakes of foods and nutrients were calculated and dietary patterns were assessed using exploratory factor analysis, using the method of principal components. Paired t-tests and correlation coefficients were used to compare the three dietary assessment methods. Results: Five distinct dietary patterns were identified using the food diary and the 48-h recall but were less consistent on the 24-h recall.  Correlations between factor scores on the 48-h recall and the food diary (r=0.13–0.67) were higher than those between the 24-h recall and food diary (r=-0.01–0.59). The recall methods were effective at ranking subjects according to food and nutrient intakes, with the 48-h recall and food diary showing higher correlations in both males and females. Conclusions: This study indicates that a 48-h recall effectively characterises dietary patterns in British adults when compared to a food diary and ranks participants appropriately with respect to most nutrients and foods and is superior to a single 24-h recall. These results have implications for longitudinal studies where maximising response rates to repeat dietary assessment tools is essential.

Supplement use is associated with health status and health-related behaviors in the 1946 British birth cohort.

Use of dietary supplements may be one of a number of health-related behaviors that cluster together. The current study investigated the underlying diet, health-related characteristics, and behaviors of users and nonusers of dietary supplements in a longitudinal study of health. Participants (n = 1776) completed a 5-d food diary including information on dietary supplement use (vitamins, minerals, and nutraceuticals) at age 53 y. Sociodemographic information and data on smoking, alcohol, and physical activity were obtained along with anthropometric measurements, blood pressure, and a blood sample (nonfasting subjects). A significantly greater percentage of women reported supplement use compared with men (45.1 vs. 25.2%). Supplement use was associated with lower BMI, lower waist circumference, higher plasma folate and plasma vitamin B-12 concentrations, nonsmoking, participation in physical activity, and nonmanual social class in women and with plasma folate concentrations and participation in physical activity in men. Nonsupplement users tended to be nonconsumers of breakfast cereals, fruit, fruit juice, yogurt, oily fish, and olive oil and had lower dietary intakes of potassium, magnesium, phosphorus, iron, and vitamin C even after adjustment for sociodemographic and behavioral factors. Overall, supplement users tended to differ from nonsupplement users on a range of health-related behaviors and health status indicators, although there were fewer significant associations in men. Similarly, dietary supplements users tended to have underlying diets that, were healthier and those taking supplements may be the least likely to need them. These results support the notion of a clustering of healthy behaviors and cardiovascular risk factors, particularly for women.

Health-related quality of life and metabolic control in children with type 1 diabetes : a prospective cohort study

OBJECTIVE—To assess change in health-related quality of life (HRQOL) in children with diabetes over 2 years and determine its relationship to change in metabolic control.

RESEARCH DESIGN AND METHODS—In 1998, parents of children aged 5–18 years attending a tertiary diabetes clinic reported their child’s HRQOL using the Child Health Questionnaire PF-50. Those aged 12–18 years also self-reported their HRQOL using the analogous Child Health Questionnaire CF-80. HbA_1c levels were recorded. In 2000, identical measures were collected for those who were aged ≤18 years and still attending the clinic.

RESULTS—Of 117 eligible subjects, 83 (71%) participated. Parents reported no significant difference in children’s HRQOL at baseline and follow-up. However, adolescents reported significant improvements on the Family Activities (P < 0.001), Bodily Pain (P = 0.04), and General Health Perceptions (P = 0.001) scales and worsening on the Behavior (P = 0.04) scale. HbA1c at baseline and follow-up were strongly correlated (r = 0.57). HbA_1c increased significantly (mean 7.8% in 1998 vs. 8.5% in 2000; P < 0.001), with lower baseline HbA_1c strongly predicting an increase in HbA_1c over the 2 years (r² = 0.25, P < 0.001). Lower parent-reported Physical Summary and adolescent-reported Physical Functioning scores at baseline also predicted increasing HbA_1c. Poorer parent-reported Psychosocial Summary scores were related to higher HbA_1c at both times but did not predict change in HbA_1c.

CONCLUSIONS—Changes in parent and adolescent reports of HRQOL differ. Better physical functioning may protect against deteriorating HbA_1c, at least in the medium term. While the HRQOL of children with diabetes does not appear to deteriorate over time, we should not be complacent, as it is consistently poorer than that of their healthy peers.

Fruit and vegetable consumption and stroke : meta-analysis of cohort studies

Background
Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of stroke in most epidemiological studies, although the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of stroke in a meta-analysis of cohort studies.

Methods
We searched MEDLINE, EMBASE, the Cochrane Library, and bibliographies of retrieved articles. Studies were included if they reported relative risks and corresponding 95% CIs of stroke with respect to frequency of fruit and vegetable intake.

Findings
Eight studies, consisting of nine independent cohorts, met the inclusion criteria. These groups included 257 551 individuals (4917 stroke events) with an average follow-up of 13 years. Compared with individuals who had less than three servings of fruit and vegetables per day, the pooled relative risk of stroke was 0·89 (95% CI 0·83–0·97) for those with three to five servings per day, and 0·74 (0·69–0·79) for those with more than five servings per day. Subgroup analyses showed that fruit and vegetables had a significant protective effect on both ischaemic and haemorrhagic stroke.

Interpretation
Increased fruit and vegetable intake in the range commonly consumed is associated with a reduced risk of stroke. Our results provide strong support for the recommendations to consume more than five servings of fruit and vegetables per day, which is likely to cause a major reduction in strokes.

Changes in sedentary behavior among adolescent girls: a 2.5-Year prospective cohort study

Purpose: To describe longitudinal changes in leisure-time sedentary behavior among girls, during early to mid-adolescence. Methods: A 2.5-year prospective cohort study, comprising 5 data collections, 6 months apart, between 2000 and 2002. Girls aged 12–15 years (n = 200) from 8 high schools located in Sydney, Australia, self-reported the usual time spent each week in a comprehensive range of sedentary behaviors.  Results: Retention rate for the study was 82%. Girls aged 12.8 years spent approximately 45% of their discretionary time in sedentary behavior, which increased to 63% at age 14.9 years. Watching TV, videos, and playing video games (small screen recreation; SSR) was the most popular sedentary pastime, accounting for 33% of time spent in sedentariness, followed by homework and reading (25%). Sedentary behavior increased 1.4 and 3.3 hours on week and weekend days, respectively. On weekdays, increased time was spent on hobbies (27 min/day) and on weekend days, increased time was spent sitting around talking with friends (60 min/day), computer use (37 min/day), and television viewing (34 min/day). Conclusions: Among girls, the transition between early and mid-adolescence was accompanied by a significant increase in leisure-time sedentary behavior. Interventions to reduce sedentariness among adolescent girls are best to focus on weekend behaviors. Studies seeking to examine the association between inactivity and the development of chronic health problems need to examine a diverse range of activities that comprehensively measure sedentariness. This information will provide a better understanding of inactivity patterns among adolescent girls.

Effects of a walking program in the psychiatric in-patient treatment setting: a cohort study.

Issue addressed: To assess the effectiveness of a walking program in a psychiatric in-patient unit. Method: In-patients at a private psychiatric unit were offered the opportunity to participate in a daily morning 40 minute walk led by an activity supervisor. After discharge, outcomes for patients who had regularly participated in the walking group (n=35) and patients who had not participated (n=49) were compared for length of stay during their period of admission and Clinical Global Impression - Severity (CGI-S) and  Depression Anxiety Stress Scales (DASS) scores measured at admission and discharge. This was a retrospective analysis of data collected routinely. Results: There were no significant differences between the two cohorts on most primary outcome measures, including length of stay, DASS scores at admission and at discharge and CGI-S scores at admission. Patients who had not participated in the walking group had a significantly lower score on a single measure, the CGI-S, than patients who had participated (p=0.001). Conclusions: This study showed no evidence that in-patients benefited from participating in the physical activity program. However, this must be  interpreted within the confines of a number of study limitations and, as such, the findings can neither support nor refute the effectiveness of physical activities.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background
While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).
Methods
This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.
Results
Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion
Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies

Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of coronary heart disease (CHD) in many epidemiological studies, however, the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of CHD by carrying out a meta-analysis of cohort studies. Studies were included if they reported relative risks (RRs) and corresponding 95% confidence interval (CI) of CHD with respect to frequency of fruit and vegetable intake. Twelve studies, consisting of 13 independent cohorts, met the inclusion criteria. There were 278 459 individuals (9143 CHD events) with a median follow-up of 11 years. Compared with individuals who had less than 3 servings/day of fruit and vegetables, the pooled RR of CHD was 0.93 (95% CI: 0.86–1.00, P=0.06) for those with 3–5 servings/day and 0.83 (0.77–0.89, P<0.0001) for those with more than 5 servings/day. Subgroup analyses showed that both fruits and vegetables had a significant protective effect on CHD. Our meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3–5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.

Plasma phospholipid fatty acid composition as a biomarker of habitual dietary fat intake in an ethnically diverse cohort

Background and aim
As an evaluation of fatty acid intake measurement, our aim was to examine associations between diet and plasma phospholipid (PL) fatty acids, and whether these were modified by age, sex, country of birth, fasting status, use of cholesterol-lowering medication, body size, chronic disease and other lifestyle factors.

Methods and results
Cross-sectional analysis of plasma PL fatty acid composition and dietary fatty acid intake over 12 months from a 121-item food frequency questionnaire (FFQ) in 4439 men and women aged 40–69 years, born in Australia, Greece or Italy. Crude correlation coefficients ranged from 0.18 to 0.40; and corrected correlation coefficients from 0.38 to 0.78 for total monounsaturated, polyunsaturated, n-6, n-3 fatty acids, oleic acid, linoleic acid, EPA and DHA. Weaker associations were observed for other fatty acids. The associations did not vary significantly by fasting status, use of lipid lowering medication or alcohol intake, but for some fatty acids did vary by sex, age, body mass index, country of birth, smoking and previous heart attack or diabetes.

Conclusions
The FFQ provides useful information on intakes of mono- and polyunsaturated fatty acids. Correlations did not differ by fasting status, or use of lipid-lowering medication.

Online self and peer assessment in large, multi-campus, multi-cohort contexts

The increasing use of team assignments within higher education is well documented. The driving forces behind this include desires to facilitate reflective and collaborative learning, to develop generic teamwork skills for graduate employment and to reduce the grading workloads of faculty staff. Students however consistently report dissatisfaction when the assessment of team assignments produces a common grade for all team members. Self-andpeer-assessment (SAPA) is presented as a fair, valid and reliable method of producing information about ongoing team processes. This information can provide ongoing feedback to team members and rich formative data to instructors attempting to assess the team process and students’ teamwork skills. This data can also enable individualised summative assessment in dysfunctional teams or situations of uneven team member contributions. Whilst manual SAPA protocols can work effectively for smaller classes, computer-assisted SAPA offers a solution to the problems of large classes. This paper reports on the early stages of an online SAPA tool, originally developed for small classes of architecture students, adapted for use by very large business communication classes comprising up to 1000 students in a semester. This large unit is delivered on four Australian campuses as well as off-campus and in off-shore mode, by up to fourteen instructors at any one time. The paper documents how three researchers from very different backgrounds worked to create their own research team, implement a pilot study, and adapt the online tool, whilst adhering to comparability of assessment constraints and maintaining integrity of research design.

Stability of body mass index in Australian children: a prospective cohort study across the middle childhood years

Objective: To investigate the prevalence and incidence of overweight and obesity, the frequency of overweight resolution and the influence of parental adiposity during middle childhood.

Design: As part of a prospective cohort study, height and weight were measured in 1997 and 2000/2001. Children were classified as non-overweight, overweight or obese based on standard international definitions. Body mass index (BMI) was transformed into age- and gender-specific Z-scores employing the LMS method and 2000 growth chart data of the Centers for Disease Control and Prevention. Parents self-reported height and weight, and were classified as underweight, healthy weight, overweight or obese based on World Health Organization definitions.

Setting: Primary schools in Victoria, Australia.

Subjects: In total, 1438 children aged 5–10 years at baseline.

Results: The prevalence of overweight and obesity increased between baseline (15.0 and 4.3%, respectively) and follow-up (19.7 and 4.8%, respectively; P < 0.001 for increase in overweight and obesity combined). There were 140 incident cases of overweight (9.7% of the cohort) and 24 of obesity (1.7% of the cohort); only 3.8% of the cohort (19.8% of overweight/obese children) resolved to a healthy weight. The stability of child adiposity as measured by BMI category (84.8% remained in the same category) and BMI Z-score (r = 0.84; mean change = −0.05) was extremely high. Mean change in BMI Z-score decreased with age (linear trend β = 0.03, 95% confidence interval 0.01–0.05). The influence of parental adiposity largely disappeared when children's baseline BMI was adjusted for.

Conclusions: During middle childhood, the incidence of overweight/obesity exceeds the proportion of children resolving to non-overweight. However, for most children adiposity remains stable, and stability appears to increase with age. Prevention strategies targeting children in early childhood are required.

Hepatitis B Virus transmission and hepatocarcinogenesis: a 9 year retropective cohort of 13676 relatives with hepatocellular carcinoma

Background/Aims
Familial clustering of hepatitis B virus (HBV) infection is related to perinatal transmission, and is the main cause of familial-type hepatocellular carcinoma (HCC). The route of HBV transmission differs between the children and siblings of patients with HCC. This study examined the differences in HBV carrier rates and HCC-related mortality between two generations in HCC families.
Methods
From 1992 to 1997, relatives of individuals with HCC were screened prospectively with ultrasonography, alpha-fetoprotein, liver biochemistry tests and viral markers. Total HCC-related deaths during a 9-year period were compared between the generations of index patients and their children.
Results
The study included a total of 13 676 relatives in two generations. More HCC-related deaths occurred in the index patient generation than in the child generation. Furthermore, children of female index patients had higher rates of liver cancer related mortality than children of male index patients. The same was true when the analysis was limited to male HBV carriers. The prevalence of HBsAg in the offspring of HBsAg positive mothers was 66% in the child generation and 72% in the index patient generation. These high prevalences indicated high maternal HBV replication status.
Conclusions
Perinatal transmission and maternal viral load are important risk factors in hepatocarcinogenesis.