A threshold analysis of dengue transmission in terms of weather variables and imported dengue cases in Australia

Dengue virus (DENV) transmission in Australia is driven by weather factors and imported dengue fever (DF) cases. However, uncertainty remains regarding the threshold effects of high-order interactions among weather factors and imported DF cases and the impact of these factors on autochthonous DF. A time-series regression tree model was used to assess the threshold effects of natural temporal variations of weekly weather factors and weekly imported DF cases in relation to incidence of weekly autochthonous DF from 1 January 2000 to 31 December 2009 in Townsville and Cairns, Australia. In Cairns, mean weekly autochthonous DF incidence increased 16.3-fold when the 3-week lagged moving average maximum temperature was <32 °C, the 4-week lagged moving average minimum temperature was ≥24 °C and the sum of imported DF cases in the previous 2 weeks was >0. When the 3-week lagged moving average maximum temperature was ≥32 °C and the other two conditions mentioned above remained the same, mean weekly autochthonous DF incidence only increased 4.6-fold. In Townsville, the mean weekly incidence of autochthonous DF increased 10-fold when 3-week lagged moving average rainfall was ≥27 mm, but it only increased 1.8-fold when rainfall was <27 mm during January to June. Thus, we found different responses of autochthonous DF incidence to weather factors and imported DF cases in Townsville and Cairns. Imported DF cases may also trigger and enhance local outbreaks under favorable climate conditions.

Spatiotemporal patterns of Japanese Encephalitis in China, 2002–2010

OBJECTIVE The aim of the study is to examine the spatiotemporal pattern of Japanese Encephalitis (JE) in mainland China during 2002-2010. Specific objectives of the study were to quantify the temporal variation in incidence of JE cases, to determine if clustering of JE cases exists, to detect high risk spatiotemporal clusters of JE cases and to provide evidence-based preventive suggestions to relevant stakeholders. METHODS Monthly JE cases at the county level in mainland China during 2002-2010 were obtained from the China Information System for Diseases Control and Prevention (CISDCP). For the purpose of the analysis, JE case counts for nine years were aggregated into four temporal periods (2002; 2003-2005; 2006; and 2007-2010). Local Indicators of Spatial Association and spatial scan statistics were performed to detect and evaluate local high risk space-time clusters. RESULTS JE incidence showed a decreasing trend from 2002 to 2005 but peaked in 2006, then fluctuated over the study period. Spatial cluster analysis detected high value clusters, mainly located in Southwestern China. Similarly, we identified a primary spatiotemporal cluster of JE in Southwestern China between July and August, with the geographical range of JE transmission increasing over the past years. CONCLUSION JE in China is geographically clustered and its spatial extent dynamically changed during the last nine years in mainland China. This indicates that risk factors for JE infection are likely to be spatially heterogeneous. The results may assist national and local health authorities in the development/refinement of a better preventive strategy and increase the effectiveness of public health interventions against JE transmission.

The baby boomers and beyond report : physical activity levels of older Western Australians 2006

Participation in sufficient levels of physical activity provides significant health benefits, particularly in older adults. The monitoring of physical activity levels in the Western Australian population is therefore necessary for developing and implementing strategies and programs for increasing participation. The Premier’s Physical Activity Taskforce (PATF) conducted a survey in 2006 to measure physical activity levels among Western Australian adults to follow-up the 1999 and 2002 state physical activity surveys. There is now widespread agreement that many health problems of older life – including the onset of frailty and disability – can be postponed or delayed by adopting health-enhancing habits such as physical activity. Adults over 65 years are the most rapidly growing age group and will continue to rise as more persons turn 65. If older adults could be encouraged to be more active as they age, frailty and disability associated with falls would be reduced, and function and physical and mental health in older people would be improved thereby reducing the burden of disease and injury. Given that physical inactivity is one of the most important and modifiable risk factors contributing to ill health, particularly for people as they age, the overall aim of this study was to examine patterns of physical activity in those aged 45 years and over – referred to hereafter as baby boomers+ – in more detail.

Using GPS technology to (re)-examine operational definitions of 'neighbourhood' in place-based health research

BACKGROUND Inconsistencies in research findings on the impact of the built environment on walking across the life course may be methodologically driven. Commonly used methods to define 'neighbourhood', from which built environment variables are measured, may not accurately represent the spatial extent to which the behaviour in question occurs. This paper aims to provide new methods for spatially defining 'neighbourhood' based on how people use their surrounding environment. RESULTS Informed by Global Positioning Systems (GPS) tracking data, several alternative neighbourhood delineation techniques were examined (i.e., variable width, convex hull and standard deviation buffers). Compared with traditionally used buffers (i.e., circular and polygon network), differences were found in built environment characteristics within the newly created 'neighbourhoods'. Model fit statistics indicated that exposure measures derived from alternative buffering techniques provided a better fit when examining the relationship between land-use and walking for transport or leisure. CONCLUSIONS This research identifies how changes in the spatial extent from which built environment measures are derived may influence walking behaviour. Buffer size and orientation influences the relationship between built environment measures and walking for leisure in older adults. The use of GPS data proved suitable for re-examining operational definitions of neighbourhood.

Access to commercial destinations within the neighbourhood and walking among Australian older adults

BACKGROUND: Physical activity, particularly walking, is greatly beneficial to health; yet a sizeable proportion of older adults are insufficiently active. The importance of built environment attributes for walking is known, but few studies of older adults have examined neighbourhood destinations and none have investigated access to specific, objectively-measured commercial destinations and walking. METHODS: We undertook a secondary analysis of data from the Western Australian state government's health surveillance survey for those aged 65--84 years and living in the Perth metropolitan region from 2003--2009 (n = 2,918). Individual-level road network service areas were generated at 400 m and 800 m distances, and the presence or absence of six commercial destination types within the neighbourhood service areas identified (food retail, general retail, medical care services, financial services, general services, and social infrastructure). Adjusted logistic regression models examined access to and mix of commercial destination types within neighbourhoods for associations with self-reported walking behaviour. RESULTS: On average, the sample was aged 72.9 years (SD = 5.4), and was predominantly female (55.9%) and married (62.0%). Overall, 66.2% reported some weekly walking and 30.8% reported sufficient walking (>=150 min/week). Older adults with access to general services within 400 m (OR = 1.33, 95% CI = 1.07-1.66) and 800 m (OR = 1.20, 95% CI = 1.02-1.42), and social infrastructure within 800 m (OR = 1.19, 95% CI = 1.01-1.40) were more likely to engage in some weekly walking. Access to medical care services within 400 m (OR = 0.77, 95% CI = 0.63-0.93) and 800 m (OR = 0.83, 95% CI = 0.70-0.99) reduced the odds of sufficient walking. Access to food retail, general retail, financial services, and the mix of commercial destination types within the neighbourhood were all unrelated to walking. CONCLUSIONS: The types of neighbourhood commercial destinations that encourage older adults to walk appear to differ slightly from those reported for adult samples. Destinations that facilitate more social interaction, for example eating at a restaurant or church involvement, or provide opportunities for some incidental social contact, for example visiting the pharmacy or hairdresser, were the strongest predictors for walking among seniors in this study. This underscores the importance of planning neighbourhoods with proximate access to social infrastructure, and highlights the need to create residential environments that support activity across the life course.

Environmental factors associated with active living in retirement village residents : findings from an exploratory qualitative enquiry

This exploratory enquiry employs qualitative methods to advance knowledge and understanding of physical environmental attributes related to active living among residents of Australian retirement villages. Six focus groups (n = 51 residents) were held and participants described how their current, and subsequently ideal, retirement village and neighborhood supported active lifestyles. Thematic analysis revealed three key environmental factors associated with active living: a positive social environment within the village; services and facilities provided in the village and wider neighborhood; and the presence of suitable pedestrian infrastructure. The unique discovery that environmental factors of both the retirement village and the surrounding neighborhood were associated with residents’ active living raises many questions for study. Findings informed the development of a survey instrument, and further understanding in this area has the potential to contribute to the design and siting practices of senior housing complexes within neighborhoods.

Selling new neighborhoods as good for walking : issues for measuring self-selection

Background: Self-selection-whether individuals inclined to walk more seek to live in walkable environments-must be accounted for when studying built environment influences on walking. The way neighborhoods are marketed to future residents has the potential to sway residential location choice, and may consequently affect measures of self-selection related to location preferences. We assessed how walking opportunities are promoted to potential buyers, by examining walkability attributes in marketing materials for housing developments. Methods: A content analysis of marketing materials for 32 new housing developments in Perth, Australia was undertaken, to assess how walking was promoted in the text and pictures. Housing developments designed to be pedestrian-friendly (LDs) were compared with conventional developments (CDs). Results: Compared with CDs, LD marketing materials had significantly more references to 'public transport,' small home sites,' walkable parks/open space,' ease of cycling,' safe environment,' and 'boardwalks.' Other walkability attributes approached significance. Conclusion: Findings suggest the way neighborhoods are marketed may contribute to self-reported reasons for choosing particular neighborhoods, especially when attributes are not present at the time of purchase. The marketing of housing developments may be an important factor to consider when measuring self-selection, and its influence on the built environment and walking relationship.

People living in hilly residential areas in metropolitan Perth have less diabetes : spurious association or important environmental determinant?

BACKGROUND: Variations in 'slope' (how steep or flat the ground is) may be good for health. As walking up hills is a physiologically vigorous physical activity and can contribute to weight control, greater neighbourhood slopes may provide a protective barrier to weight gain, and help prevent Type 2 diabetes onset. We explored whether living in 'hilly' neighbourhoods was associated with diabetes prevalence among the Australian adult population. METHODS: Participants ([greater than or equal to]25years; n=11,406) who completed the Western Australian Health and Wellbeing Surveillance System Survey (2003-2009) were asked whether or not they had medically-diagnosed diabetes. Geographic Information Systems (GIS) software was used to calculate a neighbourhood mean slope score, and other built environment measures at 1600m around each participant's home. Logistic regression models were used to predict the odds of self-reported diabetes after progressive adjustment for individual measures (i.e., age, sex), socioeconomic status (i.e., education, income), built environment, destinations, nutrition, and amount of walking. RESULTS: After full adjustment, the odds of self-reported diabetes was 0.72 (95% CI 0.55-0.95) and 0.52 (95% CI 0.39-0.69) for adults living in neighbourhoods with moderate and higher levels of slope, respectively, compared with adults living in neighbourhoods with the lowest levels of slope. The odds of having diabetes was 13% lower (odds ratio 0.87; 95% CI 0.80-0.94) for each increase of one percent in mean slope. CONCLUSIONS: Living in a hilly neighbourhood may be protective of diabetes onset or this finding is spurious. Nevertheless, the results are promising and have implications for future research and the practice of flattening land in new housing developments.

The impact of the built environment on health across the life course : design of a cross-sectional data linkage study

Introduction: The built environment is increasingly recognised as being associated with health outcomes. Relationships between the built environment and health differ among age groups, especially between children and adults, but also between younger, mid-age and older adults. Yet few address differences across life stage groups within a single population study. Moreover, existing research mostly focuses on physical activity behaviours, with few studying objective clinical and mental health outcomes. The Life Course Built Environment and Health (LCBEH) project explores the impact of the built environment on self-reported and objectively measured health outcomes in a random sample of people across the life course. Methods and analysis: This cross-sectional data linkage study involves 15 954 children (0–15 years), young adults (16–24 years), adults (25–64 years) and older adults (65+years) from the Perth metropolitan region who completed the Health and Wellbeing Surveillance System survey administered by the Department of Health of Western Australia from 2003 to 2009. Survey data were linked to Western Australia's (WA) Hospital Morbidity Database System (hospital admission) and Mental Health Information System (mental health system outpatient) data. Participants’ residential address was geocoded and features of their ‘neighbourhood’ were measured using Geographic Information Systems software. Associations between the built environment and self-reported and clinical health outcomes will be explored across varying geographic scales and life stages. Ethics and dissemination: The University of Western Australia's Human Research Ethics Committee and the Department of Health of Western Australia approved the study protocol (#2010/1). Findings will be published in peer-reviewed journals and presented at local, national and international conferences, thus contributing to the evidence base informing the design of healthy neighbourhoods for all residents.

Perceptions of the built environment and associations with walking among retirement village residents

Housing options, such as retirement villages, that promote and encourage healthy behaviors are needed to accommodate the growing older adult population. To examine how environmental perceptions relate to walking, residents of retirement villages in Perth, Australia, were sampled, and associations between a wide range of village and neighborhood environmental attributes and walking leisurely, briskly, and for transport were examined. Perceived village features associated with walking included aesthetics (odds ratio [OR] = 1.72), personal safety (OR = 0.43), and services and facilities (OR = 0.80), whereas neighborhood attributes included fewer physical barriers (OR = 1.37) and proximate destinations (OR = 1.93). Findings suggest that locating retirement villages in neighborhoods with many local destinations may encourage more walking than providing many services and facilities within villages. Indeed, safe villages rich with amenities were shown to be related to less walking in residents. These findings have implications for the location, design, and layout of retirement villages.

Exploring socioecological correlates of active living in retirement village residents

This study explored individual, social, and built environmental attributes in and outside of the retirement village setting and associations with various active living outcomes including objectively measured physical activity, specific walking behaviors, and social participation. Residents in Perth, Australia (N = 323), were surveyed on environmental perceptions of the village and surrounding neighborhood, self-reported physical activity, and demographic characteristics and wore accelerometers. Managers (N = 32) were surveyed on village characteristics, and objective neighborhood measures were generated in a Geographic Information System (GIS). Results indicated that built- and social-environmental attributes within and outside of retirement villages were associated with active living among residents; however, salient attributes varied depending on the specific outcome considered. Findings suggest that locating villages close to destinations is important for walking and that locating them close to previous and familiar neighborhoods is important for social participation. Further understanding and consideration into retirement village designs that promote both walking and social participation are needed.

The impact of neighborhood walkability on walking : does it differ across adult life stage and does neighborhood buffer size matter?

We explored the impact of neighborhood walkability on young adults, early-middle adults, middle-aged adults, and older adults' walking across different neighborhood buffers. Participants completed the Western Australian Health and Wellbeing Surveillance System Survey (2003–2009) and were allocated a neighborhood walkability score at 200 m, 400 m, 800 m, and 1600 m around their home. We found little difference in strength of associations across neighborhood size buffers for all life stages. We conclude that neighborhood walkability supports more walking regardless of adult life stage and is relevant for small (e.g., 200 m) and larger (e.g., 1600 m) neighborhood buffers.

Examining correlates of self-reported and objectively measured physical activity among retirement village residents

Aim Physical activity (PA) patterns of retirement village residents were investigated using self-report and objective measures. Methods Residents (n = 323) from retirement villages in Perth, Australia, were surveyed on PA behaviour and various demographic, residency, health-related and mobility factors. Most participants wore accelerometers for 7 days. Retirement village managers (n = 32) were surveyed on village descriptive characteristics, including the provision of amenities and facilities. Logistic regression models examined village and resident characteristics associated with PA. Results Based on objective measurement, only 27.1% of participants were sufficiently active (n = 288). Walking was one of the most popular PA modes. Few village characteristics were associated with PA; however, villages located in more walkable neighbourhoods increased participants’ odds of transport walking. Travelling outside the village daily also increased PA odds. Conclusions Most residents were insufficiently active to gain health benefits. Considering individual and environmental factors, within the retirement village and neighbourhood settings, and associations with PA, warrants attention.

GIS and qualitative data on young mothers’ use of urban neighbourhoods for physical activity

Public health research consistently demonstrates the salience of neighbourhood as a determinant of both health-related behaviours and outcomes across the human life course. This paper will report on the findings from a mixed-methods Brisbane-based study that explores how mothers with primary school children from both high and low socioeconomic suburbs use the local urban environment for the purpose of physical activity. Firstly, we demonstrate findings from an innovative methodology using the geographic information systems (GIS) embedded in social media platforms on mobile phones to track locations, resource-use, distances travelled, and modes of transport of the families in real-time; and secondly, we report on qualitative data that provides insight into reasons for differential use of the environment by both groups. Spatial/mapping and statistical data showed that while the mothers from both groups demonstrated similar daily routines, the mothers from the high SEP suburb engaged in increased levels of physical activity, travelled less frequently and less distance by car, and walked more for transport. The qualitative data revealed differences in the psychosocial processes and characteristics of the households and neighbourhoods of the respective groups, with mothers in the lower SEP suburb reporting more stress, higher conflict, and lower quality relationships with neighbours.