The use of kernel density estimation to examine associations between neighborhood destination intensity and walking and physical activity

BACKGROUND: Local destinations have previously been shown to be associated with higher levels of both physical activity and walking, but little is known about how the distribution of destinations is related to activity. Kernel density estimation is a spatial analysis technique that accounts for the location of features relative to each other. Using kernel density estimation, this study sought to investigate whether individuals who live near destinations (shops and service facilities) that are more intensely distributed rather than dispersed: 1) have higher odds of being sufficiently active; 2) engage in more frequent walking for transport and recreation. METHODS: The sample consisted of 2349 residents of 50 urban areas in metropolitan Melbourne, Australia. Destinations within these areas were geocoded and kernel density estimates of destination intensity were created using kernels of 400m (meters), 800m and 1200m. Using multilevel logistic regression, the association between destination intensity (classified in quintiles Q1(least)-Q5(most)) and likelihood of: 1) being sufficiently active (compared to insufficiently active); 2) walking≥4/week (at least 4 times per week, compared to walking less), was estimated in models that were adjusted for potential confounders. RESULTS: For all kernel distances, there was a significantly greater likelihood of walking≥4/week, among respondents living in areas of greatest destinations intensity compared to areas with least destination intensity: 400m (Q4 OR 1.41 95%CI 1.02-1.96; Q5 OR 1.49 95%CI 1.06-2.09), 800m (Q4 OR 1.55, 95%CI 1.09-2.21; Q5, OR 1.71, 95%CI 1.18-2.48) and 1200m (Q4, OR 1.7, 95%CI 1.18-2.45; Q5, OR 1.86 95%CI 1.28-2.71). There was also evidence of associations between destination intensity and sufficient physical activity, however these associations were markedly attenuated when walking was included in the models. CONCLUSIONS: This study, conducted within urban Melbourne, found that those who lived in areas of greater destination intensity walked more frequently, and showed higher odds of being sufficiently physically active-an effect that was largely explained by levels of walking. The results suggest that increasing the intensity of destinations in areas where they are more dispersed; and or planning neighborhoods with greater destination intensity, may increase residents' likelihood of being sufficiently active for health.

A qualitative study of environmental factors important for physical activity in rural adults

PURPOSE: Despite increasing evidence that the physical environment impacts on physical activity among urban-dwellers, little attention has been devoted to understanding this relationship in rural populations. Work in this area is further hindered by a lack of environmental measures specifically designed for rural settings. This qualitative study aimed to explore the salience of urban physical activity environment constructs among rural adults. METHODS: In 2011, 49 rural men and women from three distinct areas (coastal, animal-based farming, forestry/plant-based farming) of rural Tasmania, Australia, were purposively recruited to participate in semi-structured interviews. Interviews explored features of the built and social environment commonly examined in studies of urban adults, including functional characteristics (eg, lighting, footpaths, roads/verges), road and personal safety, availability and accessibility of places to be active, destinations, and aesthetics. Interviews were recorded, transcribed verbatim and analysed using a content-thematic approach using QSR NVivo software. FINDINGS: While some urban environmental constructs were salient to these rural adults, such as availability of and accessibility to places to be active, some constructs were operationalised differently, such as road safety (where large trucks and winding roads rather than traffic density was of concern), or were not considered relevant (eg, personal safety related to crime, availability of walkable destinations, aesthetics). CONCLUSIONS: The measurement of the physical environment in rural populations may require reconsideration and/or modification to ensure salience and appropriate quantification of associations with physical activity in future studies.

Validity and reliability of field-based measures for assessing movement skill competency in lifelong physical activities: a systematic review

Background: It has been suggested that young people should develop competence in a variety of ‘lifelong physical activities’ to ensure that they can be active across the lifespan. Objective: The primary aim of this systematic review is to report the methodological properties, validity, reliability, and test duration of field-based measures that assess movement skill competency in lifelong physical activities. A secondary aim was to clearly define those characteristics unique to lifelong physical activities. Data Sources: A search of four electronic databases (Scopus, SPORTDiscus, ProQuest, and PubMed) was conducted between June 2014 and April 2015 with no date restrictions. Study Selection: Studies addressing the validity and/or reliability of lifelong physical activity tests were reviewed. Included articles were required to assess lifelong physical activities using process-oriented measures, as well as report either one type of validity or reliability. Study Appraisal and Synthesis Methods: Assessment criteria for methodological quality were adapted from a checklist used in a previous review of sport skill outcome assessments. Results: Movement skill assessments for eight different lifelong physical activities (badminton, cycling, dance, golf, racquetball, resistance training, swimming, and tennis) in 17 studies were identified for inclusion. Methodological quality, validity, reliability, and test duration (time to assess a single participant), for each article were assessed. Moderate to excellent reliability results were found in 16 of 17 studies, with 71 % reporting inter-rater reliability and 41 % reporting intra-rater reliability. Only four studies in this review reported test–retest reliability. Ten studies reported validity results; content validity was cited in 41 % of these studies. Construct validity was reported in 24 % of studies, while criterion validity was only reported in 12 % of studies. Limitations: Numerous assessments for lifelong physical activities may exist, yet only assessments for eight lifelong physical activities were included in this review. Generalizability of results may be more applicable if more heterogeneous samples are used in future research. Conclusion: Moderate to excellent levels of inter- and intra-rater reliability were reported in the majority of studies. However, future work should look to establish test–retest reliability. Validity was less commonly reported than reliability, and further types of validity other than content validity need to be established in future research. Specifically, predictive validity of ‘lifelong physical activity’ movement skill competency is needed to support the assertion that such activities provide the foundation for a lifetime of activity.

Preventing obesity in infants: the growing healthy feasibility trial protocol

INTRODUCTION: Early childhood is an important period for establishing behaviours that will affect weight gain and health across the life course. Early feeding choices, including breast and/or formula, timing of introduction of solids, physical activity and electronic media use among infants and young children are considered likely determinants of childhood obesity. Parents play a primary role in shaping these behaviours through parental modelling, feeding styles, and the food and physical activity environments provided. Children from low socio-economic backgrounds have higher rates of obesity, making early intervention particularly important. However, such families are often more difficult to reach and may be less likely to participate in traditional programs that support healthy behaviours. Parents across all socio-demographic groups frequently access primary health care (PHC) services, including nurses in community health services and general medical practices, providing unparalleled opportunity for engagement to influence family behaviours. One emerging and promising area that might maximise engagement at a low cost is the provision of support for healthy parenting through electronic media such as the Internet or smart phones. The Growing healthy study explores the feasibility of delivering such support via primary health care services.

METHODS: This paper describes the Growing healthy study, a non-randomised quasi experimental study examining the feasibility of an intervention delivered via a smartphone app (or website) for parents living in socioeconomically disadvantaged areas, for promoting infant feeding and parenting behaviours that promote healthy rather than excessive weight gain. Participants will be recruited via their primary health care practitioner and followed until their infant is 9 months old. Data will be collected via web-based questionnaires and the data collected inherently by the app itself.

ETHICS AND DISSEMINATION: This study received approval from the University of Technology Sydney Ethics committee and will be disseminated via peer-reviewed publications and conference presentations.

Measures of environmental correlates of physical activity for urban Chinese preschool-aged children: development and reliability

We adapted/developed and examined the test–retest reliability and internal consistency of eight parent-report measures of home and neighborhood environmental correlates of physical activity appropriate for Chinese preschool-aged children and their parents/primary caregivers living in densely populated urban environments. This study consisted of a qualitative (cognitive interviews) and a quantitative (test–retest reliability) component. Chinese versions of the measures were pilot-tested on 20 parents of Hong Kong preschool-aged children using cognitive interviews. Measures were then administered to 61 parents twice, 1 week apart. Test–retest reliability and internal consistency were computed. Except for two items, the test–retest reliability of items and scale summary scores ranged from moderate to excellent. The internal consistency of the measures exceeded recommended minimal values (Cronbach’s α >.70). The parent-report measures examined in this study are potentially appropriate for use in investigations of environmental correlates of the physical activity of Chinese preschool-aged children living in densely populated urban environments. However, their predictive validity with respect to Chinese preschool-aged children’s physical activity needs to be assessed in future studies.

Affective dysfunction in a mouse model of Rett syndrome: therapeutic effects of environmental stimulation and physical activity

Rett syndrome (RTT) is a neurodevelopmental disorder associated with mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2) and consequent dysregulation of brain maturation. Patients suffer from a range of debilitating physical symptoms, however, behavioral and emotional symptoms also severely affect their quality of life. Here, we present previously unreported and clinically relevant affective dysfunction in the female heterozygous Mecp2tm1Tam mouse model of RTT (129sv and C57BL6 mixed background). The affective dysfunction and aberrant anxiety-related behavior of the Mecp2+ / - mice were found to be reversible with environmental enrichment (EE) from 4 weeks of age. The effect of exercise alone (via wheel running) was also explored, providing the first evidence that increased voluntary physical activity in an animal model of RTT is beneficial for some phenotypes. Mecp2+ / - mutants displayed elevated corticosterone despite decreased Crh expression, demonstrating hypothalamic-pituitary-adrenal axis dysregulation. EE of Mecp2+ / - mice normalized basal serum corticosterone and hippocampal BDNF protein levels. The enrichment-induced rescue appears independent of the transcriptional regulation of the MeCP2 targets Bdnf exon 4 and Crh. These findings provide new insight into the neurodevelopmental role of MeCP2 and pathogenesis of RTT, in particular the affective dysfunction. The positive outcomes of environmental stimulation and physical exercise have implications for the development of therapies targeting the affective symptoms, as well as behavioral and cognitive dimensions, of this devastating neurodevelopmental disorder.

The effectiveness of a brief intervention using a pedometer and step-recording diary in promoting physical activity in people diagnosed with type 2 diabetes or impaired glucose tolerance

Issue addressed: To evaluate the effectiveness of a brief intervention using a pedometer and step-recording diary on promoting physical activity in people with type 2 diabetes or impaired glucose tolerance (IGT). Methods: People with type 2 diabetes or IGT who attended the Illawarra Diabetes Service were invited to participate. Participants in the intervention group received a pedometer and a diary to record their daily steps for a two-week period. Both the intervention and comparison group received advice on physical activity. Physical activity levels were measured using the Active Australia Survey at baseline, and at two and 20 weeks. Results: A total of 226 participants were recruited. At two-week follow-up the mean self-reported minutes of walking was significantly higher in the intervention group than the comparison group (223 minutes versus 164 minutes; p=0.01), as was the percentage of intervention participants achieving recommended levels of moderate-intensity physical activity (63.5% versus 41.8%, p=0.02) and the percentage of intervention participants achieving adequate levels of total physical activity (68.9% versus 48.0%, p=0.04). There were no differences between study groups for any physical activity measure at 20-week follow-up. Conclusions: A pedometer and a step-recording diary were useful tools to promote short-term increase in physical activity in people diagnosed with type 2 diabetes or IGT. Future studies need to examine whether a longer intervention, individualised physical activity counselling and support for achieving step goals could result in increasing physical activity over the long term.