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.

Change in women's body mass index and waist circumference, 1997 to 2002: the Nepean study

Objective: To investigate character istics associated with body mass index (BMI) and waist circumference stability over a five-year period in women with school-age children.

Methods: Women with 7–8 year-old children from western Sydney, Australia, had anthropometric measures taken in 1996/97 (n====436) and five years later (n=327). Socio-demographic characteristics examined at baseline included age, socioeconomic status, smoking, and number of children.

Results: Over five years, less than half of the women maintained a stable BMI (38.8%) or waist circumference (31.5%), with the majority gaining in both indicators of adiposity. BMI and socio-demographic characteristics were not predictive of BMI or waist circumference stability or decrease.

Conclusions and Implications: Total and abdominal adiposity increased in these Australian women who have children. The results support the need to develop effective weight gain prevention initiatives.

An investigation into the cross-cultural equivalence of the personal wellbeing index

The Personal Wellbeing Index (PWI) is being developed for the cross-cultural measurement of subjective wellbeing (SWB). This paper reports the findings of its utility with the Hong Kong Chinese and Australian populations. An item on affect, ‘satisfaction with own happiness’ was also investigated to determine whether it should be added to the index. Three-hundred and sixty participants (180 per country), with equal representation from groups aged 18–35, 35–64 and 65 years and above, were recruited from each country. The PWI demonstrated good psychometric performance in terms of its reliability, validity and sensitivity, which are comparable in both countries. The item ‘satisfaction with own happiness’ was found to contribute significantly to the scale’s psychometric performance in Australia but not in Hong Kong. Cultural differences in the perception of the concepts ‘satisfaction’ and ‘happiness’ were suggested as an explanation for this finding. The PWI data are also consistent with homeostasis theory, which proposes that each person’s SWB level is maintained within a limited positive range. For the Australian population, their mean SWB level fell within the established Western range of 70–80, on a scale from 0 to 100. The Hong Kong population, however, fell below this range. Cultural response bias was identified as a plausible explanation for the differences between the Hong Kong and Australian samples.

Family average income and body mass index above the healthy weight range among urban and rural resicents in regional Mainland China

Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.

Television, computer use and body mass index in Australian primary school children

Objective: To investigate relationships between children's body mass index (BMI) and parent reports of children's television and video game/computer habits, controlling for other potential risk factors for paediatric obesity.

Methods: Child BMI was calculated from measured height and weight collected in 1997 as part of a large, representative, cross-sectional study of children in Victoria, Australia. Parents reported the amount of time children watched television and used video games/computers, children's eating and activity habits, parental BMI and sociodemographic details.

Results: A total of 2862 children aged 5−13 years participated. Child mean BMI z-score was significantly related to television (F = 10.2₃, P < 0.001) but not video game/computer time (F = 2.2₃, P = 0.09), but accounted for only 1 and 0.2% of total BMI variance, respectively. When parental BMI, parental education, number of siblings, food intake, organized exercise and general activity level were included, television ceased to be independently significantly related to child BMI. Using adjusted logistic regression, the odds of being overweight and obese generally increased with increasing television viewing. No relationship was found for video game/computer use.
Conclusions: A small proportion of variance in child BMI was related to television, but not video game/computer time. This was far outweighed by the influence of other variables. Causal pathways are likely to be complex and interrelated.

The Index Effect: an investigation of the price and volume effects surrounding changes to the S & P Australian indices

This paper examines the stock price and volume effects surrounding the announcement of constituent changes to the S&P/ASX 200 and four supplementary indices. Between April 2000 and December 2002 additions to (deletions from) the ASX 200 were associated with a significant price rise (fall) over the 10 day period following the market announcement of the change. Deletions were also associated with a significant fall on the announcement date itself These findings were corroborated by significant increases in trading volume over the same intervals, suggesting heavy trading activity by index funds in response to changes to the ASX 200. Following the implementation of these changes, both additions and deletions experienced a significant price reversion, supporting the price pressure hypothesis. By contrast, none of the supplementary indices displayed evidence of stock price or volume effects, which precludes the information and liquidity hypotheses as viable explanations for the findings of this research.

The index of information systems journals

The aim of this publication is to provide basic information about, and links to, either paper or electronic journal web sites, and more particularly, to provide links to their instructions to authors information.

Using the personal wellbeing index in Lao PDR : issues of equivalence

Lao PDR is one of the 50 countries included in the International Wellbeing Group study which uses Cummin's (2001) Personal Wellbeing Index (PWI) to draw cross-national comparisons of subjective wellbeing. Lau, Cummins & McPherson (2005) found a statistically significant difference in PWI scores between Australian & Hong Kong. They ask whether this is a real reflection of lower quality of life in Hong Kong or whether there exists a cultural response bias which predisposes the Hong Kong population to be less willing to admit to high levels of satisfaction in the seven domains of the index. If the difference reflects cultural response bias, what factors contribute to that bias & how common is this phenomenon in the countries of South-east Asia & IndoChina? The paper addresses these questions with particular attention to Lao PDR where responses to the PWI from both urban & rural populations suggest a similar reticence about expressing high levels of satisfaction. The paper explores the sources of resistance to reporting positive subjective wellbeing & what adaptations may be needed to the Index to allow for such bias.

Interlink decision making index (IDMI) -- a simple tool/concept to assist decision making for sustainability Part 1: definition of IDMI

There is an apparent gap between the LCA or other assessment's outcomes and its effective application in the decision making process. It is needed to provide to the decision makers a simple, less human interfered mechanism that integrates all the key criteria (environmental, economic, technical and safety etc.). The proposed index: Interlink Decision Making Index (IDMI) has all these features: simple, interlink (all criteria) and automatically and quantified influence of critical criteria (ie. no human weighting needed) and is able to assist the multi-criteria decision making for sustainability based on the outcomes of specific assessments (eg. LCA, ElA etc.). The index represents a pure numerical value and does not necessarily have any physical meanings, but it reflects the total merits of a particular option once the normal decision making criteria and (up to two) critical criteria (CC) have been chosen. Then, without arbitrarily weighting process, the comparison and selection of the best possible option, ie. decision can be made based on the derived IDMI results. Two hypothetical examples are presented in part 2 of the paper to demonstrate the application of the IDMI concept and it's differences with the traditional "tabular method" in the decision making process.