Visual impairment and socioeconomic factors

BACKGROUND: Information about socioeconomic factors associated with visual impairment can assist in the design of intervention programmes. Such information was collected by the Melbourne Visual Impairment Project (Melbourne VIP). METHODS: The Melbourne VIP was a population based study of non-institutionalised permanent residents in nine suburbs of the Melbourne metropolitan area aged 40 years of age and older. A standardised eye examination was provided to eligible residents which included a structured interview. Variables of interest for this analysis were age, sex, country of birth, language spoken at home, education level, use of private health insurance, employment status, and living arrangements. Visual impairment was defined as a best corrected visual acuity < 6/18 and/or visual field constriction to within 20 degrees of fixation. RESULTS: A total of 3271 (83%) residents participated. Participants ranged in age from 40 to 98 years; 54% were female. Forty four (1.34%) were classified as visually impaired due to visual acuity and/or visual field loss. To evaluate the independent association of the significant sociodemographic variables with visual impairment, a regression model was constructed that included age, retirement status, use of private health insurance, and household arrangement. The results showed that age was the significant predictor of visual impairment (OR: 3.19; CI: 2.29-4.43), with the mean age of people with visual impairment significantly older (75.0 years) compared with people without visual impairment (58.2 years) (t test = 9.71; p = 0.0001). Of the 44 visually impaired people, 39 (87%) were aged 60 years of age and older. CONCLUSION: The results indicate that age is the most significant factor associated with visual impairment. Of some importance was the finding that people with visual impairment were less likely to have private health insurance. With the aging of the population, the number of people affected by visual impairment will increase significantly. Intervention programmes need to be established before the onset of middle age to offset the escalation of visual impairment in the older population.

Chronic condition management and self-management in Aboriginal communities in South Australia : outcomes of a longitudinal study

OBJECTIVES: This paper describes the longitudinal component of a larger mixed methods study into the processes and outcomes of chronic condition management and self-management strategies implemented in three Aboriginal communities in South Australia. The study was designed to document the connection between the application of structured systems of care for Aboriginal people and their longer-term health status. METHODS: The study concentrated on three diverse Aboriginal communities in South Australia; the Port Lincoln Aboriginal Health Service, the Riverland community, and Nunkuwarrin Yunti Aboriginal Health Service in the Adelaide metropolitan area. Repeated-measure clinical data were collected for individual participants using a range of clinical indicators for diabetes (type 1 and 2) and related chronic conditions. Clinical data were analysed using random effects modelling techniques with changes in key clinical indicators being modelled at both the individual and group levels. RESULTS: Where care planning has been in place longer than in other sites overall improvements were noted in BMI, cholesterol (high density and low density lipids) and HbA1c. These results indicate that for Aboriginal patients with complex chronic conditions, participation in and adherence to structured care planning and self-management strategies can contribute to improved overall health status and health outcomes. CONCLUSIONS: The outcomes reported here represent an initial and important step in quantifying the health benefits that can accrue for Aboriginal people living with complex chronic conditions such as diabetes, heart disease and respiratory disease. The study highlights the benefits of developing long-term working relationships with Aboriginal communities as a basis for conducting effective collaborative health research programs.

Effects of habitual physical activity and fitness on tibial cortical bone mass structure and mass distribution in pre-pubertal boys and girl: the look study

Targeted weight-bearing activities during the pre-pubertal years can improve cortical bone mass, structure and distribution, but less is known about the influence of habitual physical activity (PA) and fitness. This study examined the effects of contrasting habitual PA and fitness levels on cortical bone density, geometry and mass distribution in pre-pubertal children. Boys (n = 241) and girls (n = 245) aged 7–9 years had a pQCT scan to measure tibial mid-shaft total, cortical and medullary area, cortical thickness, density, polar strength strain index (SSIpolar) and the mass/density distribution through the bone cortex (radial distribution divided into endo-, mid- and pericortical regions) and around the centre of mass (polar distribution). Four contrasting PA and fitness groups (inactive–unfit, inactive–fit, active–unfit, active–fit) were generated based on daily step counts (pedometer, 7-days) and fitness levels (20-m shuttle test and vertical jump) for boys and girls separately. Active-fit boys had 7.3–7.7 % greater cortical area and thickness compared to inactive–unfit boys (P < 0.05), which was largely due to a 6.4–7.8 % (P < 0.05) greater cortical mass in the posterior–lateral, medial and posterior–medial 66 % tibial regions. Cortical area was not significantly different across PA-fitness categories in girls, but active-fit girls had 6.1 % (P < 0.05) greater SSIpolar compared to inactive–fit girls, which was likely due to their 6.7 % (P < 0.05) greater total bone area. There was also a small region-specific cortical mass benefit in the posterior–medial 66 % tibia cortex in active-fit girls. Higher levels of habitual PA-fitness were associated with small regional-specific gains in 66 % tibial cortical bone mass in pre-pubertal children, particularly boys.

Does parkland influence walking? The relationship between area of parkland and walking trips in Melbourne, Australia

Background : Using two different measures of park area, at three buffer distances, we sought to investigate the ways in which park area and proximity to parks, are related to the frequency of walking (for all purposes) in Australian adults. Little previous research has been conducted in this area, and results of existing research have been mixed.

Methods : Residents of 50 urban areas in metropolitan Melbourne, Australia completed a physical activity survey (n = 2305). Respondents reported how often they walked for >=10 minutes in the previous month. Walking frequency was dichotomised to 'less than weekly' (less than 1/week) and 'at least weekly' (1/week or more). Using Geographic Information Systems, Euclidean buffers were created around each respondent's home at three distances: 400metres (m), 800 m and 1200 m. Total area of parkland in each person's buffer was calculated for the three buffers. Additionally, total area of 'larger parks', (park space >= park with Australian Rules Football oval (17,862 m2)), was calculated for each set of buffers. Area of park was categorised into tertiles for area of all parks, and area of larger parks (the lowest tertile was used as the reference category). Multilevel logistic regression, with individuals nested within areas, was used to estimate the effect of area of parkland on walking frequency.

Results : No statistically significant associations were found between walking frequency and park area (total and large parks) within 400 m of respondent's homes. For total park area within 800 m, the odds of walking at least weekly were lower for those in the mid (OR 0.65, 95% CI 0.46-0.91) and highest (OR 0.65, 95% CI 0.44-0.95) tertile of park area compared to those living in areas with the least amount of park area. Similar results were observed for total park area in the 1200 m buffers. When only larger parks were investigated, again more frequent walking was less likely when respondents had access to a greater amount of park area.

Conclusions : In this study we found that more park area in residential environments reduced the odds of walking more frequently. Other area characteristics such as street connectivity and destinations may underlay these associations by negatively correlating with park area.

A comparison of Australian rural and metropolitan cardiovascular risk and mortality: the Greater Green Triangle and North West Adelaide population surveys

Objectives:
Cardiovascular (CVD) mortality disparities between rural/regional and urban-dwelling residents of Australia are persistent. Unavailability of biomedical CVD risk factor data has, until now, limited efforts to understand the causes of the disparity. This study aimed to further investigate such disparities.

Security and privacy concerns for Australian SMEs cloud adoption: empirical study of metropolitan vs regional SMEs

New national infrastructure initiatives such as the National Broadband Network (NBN) allow small and medium-sized enterprises (SMEs) in Australia to have greater access to cost effective Cloud computing. However, the ability of Cloud computing to store data remotely and share services in a dynamic environment brings with it security and privacy concerns. Evaluating these concerns is critical to address the Cloud computing underutilisation issue and leverage the benefits of costly NBN investment. This paper examines the influence of privacy and security factors on Cloud adoption by Australian SMEs in metropolitan and regional area. Data were collected from 150 Australian SMEs (specifically, 79 metropolitan SMEs and 71 regional SMEs) and structural equation modelling was used for the analysis. The findings reveal that privacy and security factors do not significantly influence the decision-making of Australian SMEs in the adoption of Cloud computing. Moreover, the results indicate that Cloud computing adoption is not influenced by the geographical location (i.e., metropolitan or regional location) of the SMEs. The findings extend the current understanding of Cloud computing adoption by Australian SMEs. The results will be useful to SMEs, Cloud service providers and policy makers devising Cloud security and privacy policies.

The role and contribution of private land in Victoria to biodiversity conservation and the protected area system

The distribution and attributes of properties involved in three major programs for biodiversity protection on private land in Victoria, Australia, was investigated to determine their role in relation to the reserve system. Overlaying of dowsets in a geographic information system, with particular emphasis on property distribution in relation to bioregional and population centres, was undertaken. Land for Wildlife agreements had greater numbers of properties and total area protected in all bioregions throughout the State, yet average protected area sizes were lower than those of conservation covenants and Trust for Nature reserves. A combination of large bioregional area and human population size tended to attract more private conservation properties and, to a lesser extent, the total area they protected. The potential contribution that such properties made to biodiversity conservation varied between bioregions. Inclusion of properties within a national reserve framework is proposed to improve the coordination and effectiveness of conservation measures.

Lifetime sport and leisure activity participation is associated with greater bone size, quality and strength in older men

Introduction: It remains uncertain whether long-term participation in regular weight-bearing exercise confers an advantage to bone structure and strength in old age. The aim of this study was to investigate the relationship between lifetime sport and leisure activity participation on bone material and structural properties at the axial and appendicular skeleton in older men (>50 years).

Methods: We used dual-energy X-ray absorptiometry (DXA) to assess hip, spine and ultradistal (UD) radius areal bone mineral density (aBMD) (n=161), quantitative ultrasound (QUS) to measure heel bone quality (n=161), and quantitative computed tomography (QCT) to assess volumetric BMD, bone geometry and strength at the spine (L₁–L₃) and mid-femur (n=111). Current (>50+ years) and past hours of sport and leisure activity participation during adolescence (13–18 years) and adulthood (19–50 years) were assessed by questionnaire. This information was used to calculate the total time (min) spent participating in sport and leisure activities and an osteogenic index (OI) score for each participant, which provides a measure of participation in weight-bearing activities.

Results: Regression analysis revealed that a greater lifetime (13–50+ years) and mid-adulthood (19–50 years) OI, but not total time (min), was associated with a greater mid-femur total and cortical area, cortical bone mineral content (BMC), and the polar moment of inertia (I _p) and heel VOS (p ranging from <0.05 to <0.01). These results were independent of age, height (or femoral length) and weight (or muscle cross-sectional area). Adolescent OI scores were not found to be significant predictors of bone structure or strength. Furthermore, no significant relationships were detected with areal or volumetric BMD at any site. Subjects were then categorized into either a high (H) or low/non-impact (L) group during adolescence (13–18 years) and adulthood (19–50+ years) according to their OI scores during each of these periods. Three groups were subsequently formed to reflect weight-bearing impact categories during adolescence and then adulthood: LL, HL and HH. Compared to the LL group, mid-femur total and cortical area, cortical BMC and I _p were 6.5–14.2% higher in the HH group. No differences were detected between the LL and HL groups.

Conclusions: In conclusion, these findings indicate that long-term regular participation in sport and leisure activities categorized according to an osteogenic index [but not the total time (min) spent participating in all sport and leisure activities] was an important determinant of bone size, quality and strength, but not BMD, at loaded sites in older men. Furthermore, continued participation in weight-bearing exercise in early to mid-adulthood appears to be important for reducing the risk of low bone strength in old age.

Aged care provision in Greater Bendigo : current provision and future requirements

In the following paper, ratios which correlate aged care places with physical infrastructure requirements are developed for the regional Victorian Local Government Area of Greater Bendigo, by analysing its existing aged care facilities. These ratios are then used in conjunction with the federal government’s population based measures to model scenarios of future aged care infrastructure requirements for Greater Bendigo. Strategies for the provision of additional residential aged care facilities are explored using a matrix governed by size and configuration. Variations in these two aspects are shown to affect the location options for future facilities in Greater Bendigo.

Exercise and calcium combined results in a Greater osteogenic effect than either factor alone: a blinded randomized placebo-controlled trial in boys

We examined the combined effects of exercise and calcium on BMC accrual in pre- and early-pubertal boys. Exercise and calcium together resulted in a 2% greater increase in femur BMC than either factor alone and a 3% greater increase in BMC at the tibia–fibula compared with the placebo group. Increasing dietary calcium seems to be important for optimizing the osteogenic effects of exercise.

Introduction: Understanding the relationship between exercise and calcium during growth is important given that the greatest benefits derived from these factors are achieved during the first two decades of life. We conducted a blinded randomized-controlled exercise–calcium intervention in pre- and early-pubertal boys to test the following hypotheses. (1) At the loaded sites (femur and tibia–fibula), exercise and calcium will produce greater skeletal benefits than either exercise or calcium alone. (2) At nonloaded sites (humerus and radius–ulna), there will be an effect of calcium supplementation.

Materials and Methods: Eighty-eight pre- and early-pubertal boys were randomly assigned to one of four study groups: moderate impact exercise with or without calcium (Ca) (Ex + Ca and Ex + placebo, respectively) or low impact exercise with or without Ca (No-Ex + Ca and No-Ex + Placebo, respectively). The intervention involved 20 minutes of either moderate- or low-impact exercise performed three times a week and/or the addition of Ca-fortified foods using milk minerals (392 ± 29 mg/day) or nonfortified foods over 8.5 months. Analysis of covariance was used to determine the main and combined effects of exercise and calcium on BMC after adjusting for baseline BMC.

Results: At baseline, no differences were reported between the groups for height, weight, BMC, or bone length. The increase in femur BMC in the Ex + Ca group was 2% greater than the increase in the Ex + placebo, No-Ex + Ca, or No-Ex + Placebo groups (all p < 0.03). At the tibia–fibula, the increase in BMC in the Ex + Ca group was 3% greater than the No-Ex + placebo group (p < 0.02) and 2% greater than the Ex + Placebo and the No-Ex + Ca groups (not significant). No effect of any group was detected at the humerus, ulna–radius, or lumbar spine for BMC, height, bone area, or volume.

Conclusions: In this group of normally active boys with adequate calcium intakes, additional exercise and calcium supplementation resulted in a 2–3% greater increase in BMC than controls at the loaded sites. These findings strengthen the evidence base for public health campaigns to address both exercise and dietary changes in children for optimizing the attainment of peak BMC.

Urban area disadvantage and physical activity: a multilevel study in Melbourne, Australia

Objective: To estimate variation between small areas in the levels of walking, cycling, jogging, and swimming and overall physical activity and the importance of area level socioeconomic disadvantage in predicting physical activity participation.

Methods: All census collector districts (CCDs) in the 20 innermost local government areas in metropolitan Melbourne, Australia, were identified and ranked by the percentage of low income households (<$400/week) living in the CCD. Fifty CCDs were randomly selected from the least, middle, and most disadvantaged septiles of the ranked CCDs and 2349 residents (58.7% participation rate) participated in a cross sectional postal survey about physical activity. Multilevel logistic regression (adjusted for extrabinomial variation) was used to estimate area level variation in walking, cycling, jogging, and swimming and in overall physical activity participation, and the importance of area level socioeconomic disadvantage in predicting physical activity participation.

Results: There were significant variations between CCDs in all activities and in overall physical participation in age and sex adjusted models; however, after adjustment for individual SES (income, occupation, education) and area level socioeconomic disadvantage, significant differences remained only for walking (p = 0.004), cycling (p = 0.003), and swimming (p = 0.024). Living in the most socioeconomically disadvantaged areas was associated with a decreased likelihood of jogging and of having overall physical activity levels that were sufficiently active for health; these effects remained after adjustment for individual socioeconomic status (sufficiently active: OR 0.70, 95% CI 0.55 to 0.90 and jogging: OR = 0.69, 95% CI 0.51 to 0.94).

Conclusion: These research findings support the need to focus on improving local environments to increase physical activity participation.

Abbreviations: SES, socioeconomic status; CCD, census collector district

Weight and place: a multilevel cross-sectional survey of area-level social disadvantage and overweight/obesity in Australia

Objective: To estimate variation between small areas in adult body mass index (BMI), and assess the importance of area level socioeconomic disadvantage in predicting BMI.

Methods: We identified all census collector districts (CCDs) in the 20 innermost Local Government Areas in metropolitan Melbourne, Australia, and ranked them by the percentage of low income households (<$400/week). In all, 50 CCDs were randomly selected from the least, middle and most disadvantaged septiles of the ranked list and 4913 residents (61.4% participation rate) completed one of two surveys. Multilevel linear regression was used to estimate area level variance in BMI and the importance of area level socioeconomic disadvantage in predicting BMI.

Results: There were significant variations in BMI between CCDs for women, even after adjustment for individual and area SES (P=0.012); significant area variation was not found for men. Living in the most versus least disadvantaged areas was associated with an average difference in BMI of 1.08 kg/m² (95% CI: 0.48–1.68 kg/m²) for women, and of 0.93 kg/m² (95% CI: 0.32–1.55 kg/m²) for men. Living in the mid versus least disadvantaged areas were associated with an average difference in BMI of 0.67 kg/m² (95% CI: 0.09–1.26 kg/m²) for women, and 0.43 kg/m² for men (95% CI: -0.16–1.01).

Conclusion: These findings suggest that area disadvantage is an important predictor of adult BMI, and support the need to focus on improving local environments to reduce socioeconomic inequalities in overweight and obesity.