Biomedical subjects

Eva Leslie

Publications and source records attributed to Eva Leslie.

11 recordsLinked to original sources

PubMed2006

Small-scale randomized controlled trials need more powerful methods of mediational analysis than the Baron-Kenny method.

OBJECTIVE: To devise more-effective physical activity interventions, the mediating mechanisms yielding behavioral change need to be identified. The Baron-Kenny method is most commonly used, but has low statistical power and may not identify mechanisms of behavioral change in small-to-medium size studies. More powerful statistical tests are available. STUDY DESIGN AND SETTING: Inactive adults (N=52) were randomized to either a print or a print-plus-telephone intervention. Walking and exercise-related social support were assessed at baseline, after the intervention, and 4 weeks later. The Baron-Kenny and three alternative methods of mediational analysis (Freedman-Schatzkin; MacKinnon et al.; bootstrap method) were used to examine the effects of social support on initial behavior change and maintenance. RESULTS: A significant mediational effect of social support on initial behavior change was indicated by the MacKinnon et al., bootstrap, and, marginally, Freedman-Schatzkin methods, but not by the Baron-Kenny method. No significant mediational effect of social support on maintenance of walking was found. CONCLUSIONS: Methodologically rigorous intervention studies to identify mediators of change in physical activity are costly and labor intensive, and may not be feasible with large samples. The use of statistically powerful tests of mediational effects in small-scale studies can inform the development of more effective interventions.

Aged↗

PubMed2006

Walkability of local communities: using geographic information systems to objectively assess relevant environmental attributes.

Geographic Information Systems (GIS) can be used to objectively measure features of the built environment that may influence adults' physical activity, which is an important determinant of chronic disease. We describe how a previously developed index of walkability was operationalised in an Australian context, using available spatial data. The index was used to generate a stratified sampling frame for the selection of households from 32 communities for the PLACE (Physical Activity in Localities and Community Environments) study. GIS data have the potential to be used to construct measures of environmental attributes and to develop indices of walkability for cities, regions or local communities.

Adult↗

PubMed2005

Residents' perceptions of walkability attributes in objectively different neighbourhoods: a pilot study.

Physical attributes of local environments may influence walking. We used a modified version of the Neighbourhood Environment Walkability Scale to compare residents' perceptions of the attributes of two neighbourhoods that differed on measures derived from Geographic Information System databases. Residents of the high-walkable neighbourhood rated relevant attributes of residential density, land-use mix (access and diversity) and street connectivity, consistently higher than did residents of the low-walkable neighbourhood. Traffic safety and safety from crime attributes did not differ. Perceived neighbourhood environment characteristics had moderate to high test-retest reliabilities. Neighbourhood environment attribute ratings may be used in population surveys and other studies.

Adult↗

PubMed2005

Family average income and body mass index above the healthy weight range among urban and rural residents 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.

Adult↗

PubMed2005

Levels of physical activity for colon cancer prevention compared with generic public health recommendations: population prevalence and sociodemographic correlates.

BACKGROUND: The proportion of Australian adults achieving physical activity levels believed to be sufficient for colon cancer prevention was estimated, and sociodemographic correlates (age, gender, educational attainment, occupation, marital status, and children in household) of meeting these levels of activity were analyzed. METHODS: Data from the 2000 National Physical Activity Survey were used to estimate the prevalence of participation in physical activity in relation to three criteria: generic public health recommendations, weekly amount of at least moderate-intensity physical activity currently believed to reduce risk of colon cancer, and weekly amount of vigorous-intensity physical activity believed to reduce risk of colon cancer. RESULTS: Overall, 46% of adults met the generic public health criterion, 26% met the colon cancer criterion based on participation in at least moderate-intensity physical activity, and 10% met the colon cancer criterion based on vigorous-intensity physical activity. Women were less likely than men to meet the colon cancer criteria. Younger and more educated persons were more likely to meet all three criteria. The most pronounced differences between gender, age, and educational attainment groups were found for meeting the amount of vigorous-intensity physical activity believed to reduce risk of colon cancer. CONCLUSIONS: The population prevalence for meeting proposed physical activity criteria for colon cancer prevention is low and much lower than that related to the more generic public health recommendations. If further epidemiologic studies confirm that high volumes and intensities of activity are required, the public health challenges for colon cancer will be significant.

Adult↗

PubMed2004

Perceived environment attributes, residential location, and walking for particular purposes.

BACKGROUND: Identifying environmental factors that can influence physical activity is a public health priority. We examined associations of perceived environmental attributes with walking for four different purposes: general neighborhood walking, walking for exercise, walking for pleasure, and walking to get to and from places. METHODS: Participants (n =399; 57% women) were surveyed by mail. They reported place of residence, walking behaviors, and perceptions of neighborhood environmental attributes. RESULTS: Men with the most positive perceptions of neighborhood "aesthetics" were significantly more likely (odds ratio [OR]=7.4) to be in the highest category of neighborhood walking. Men who perceived the weather as not inhibiting their walking were much more likely (OR=4.7) to be high exercise walkers. Women who perceived the weather as not inhibiting their walking were significantly more likely to be high neighborhood walkers (OR=3.8) and those with moderate perceptions of "accessibility" were much more likely to do more walking for pleasure (OR=3.5). CONCLUSIONS: Different environmental attributes were associated with different types of walking and these differed between men and women. Approaches to increasing physical activity might usefully focus on those attributes of the local environment that might influence particular subsets of walking behavior.

Adult↗

PubMed2004

Understanding environmental influences on walking; Review and research agenda.

BACKGROUND: Understanding how environmental attributes can influence particular physical activity behaviors is a public health research priority. Walking is the most common physical activity behavior of adults; environmental innovations may be able to influence rates of participation. METHOD: Review of studies on relationships of objectively assessed and perceived environmental attributes with walking. Associations with environmental attributes were examined separately for exercise and recreational walking, walking to get to and from places, and total walking. RESULTS: Eighteen studies were identified. Aesthetic attributes, convenience of facilities for walking (sidewalks, trails); accessibility of destinations (stores, park, beach); and perceptions about traffic and busy roads were found to be associated with walking for particular purposes. Attributes associated with walking for exercise were different from those associated with walking to get to and from places. CONCLUSIONS: While few studies have examined specific environment-walking relationships, early evidence is promising. Key elements of the research agenda are developing reliable and valid measures of environmental attributes and walking behaviors, determining whether environment-behavior relationships are causal, and developing theoretical models that account for environmental influences and their interactions with other determinants.

Environment↗

PubMed2004

Changes in neighborhood walking are related to changes in perceptions of environmental attributes.

BACKGROUND: Several studies have found significant cross-sectional associations of perceived environmental attributes with physical activity behaviors. Prospective relations with environmental factors have been examined for vigorous activity, but not for the moderate-intensity activities that environmental and policy initiatives are being designed to influence. PURPOSE: To examine prospective associations of changes in perceptions of local environmental attributes with changes in neighborhood walking. METHODS: Baseline and 10-week follow-up telephone interviews with 512 adults (49% men). RESULTS: Men who reported positive changes in aesthetics and convenience were twice as likely to increase their walking. Women who reported positive changes in convenience were more than twice as likely to have increased their walking. There were contrasting findings for men and women who reported traffic as less of a problem: Men were 61% less likely to have increased walking; however, women were 76% more likely to have done so. CONCLUSIONS: Further studies are needed to determine the possibly causal nature of such environment-behavior relations and to elucidate relevant gender differences. Such evidence will provide underpinnings for public health initiatives to increase participation in physical activity.

Adolescent↗

PubMed2003

Evaluation of an internet-based physical activity intervention: a preliminary investigation.

The Internet has the potential for delivering innovative, interactive physical activity (PA) interventions to large numbers of people. This study was designed to test the efficacy of an Internet intervention that consisted of a Web site plus 12 weekly e-mail tip sheets, compared with a waiting list control group. The Internet intervention was theory based and emphasized clear, graphical presentation of PA information. Sixty-five (30 intervention and 35 control) sedentary adult employees of several large hospitals (9 men and 56 women) were randomly assigned to 1 of the 2 study arms. Of the 65 participants, 57 completed the 1-month follow-up, and 52 completed the 3-month follow-up. At both 1 and 3 months, those in the intervention group were significantly more likely to have progressed in stage of motivational readiness for PA than participants in the control group: 1 month, c2(1, N =52) =4.05, p <.05; 3 months, c2(1, N =52) =6.45, p <.01. We hypothesized that at 1 and 3 months, the intervention group would exhibit significant increases relative to the control group on the number of minutes of moderate activity. At the 1-month assessment, the intervention group did exhibit significant increases, relative to the control group in moderate minutes, F(1, 54) =5.79, p <.05; however, at the 3-month assessment this difference was no longer significant. In addition, secondary analyses were conducted to examine total number of minutes of walking reported. At 1 month, the intervention group did exhibit significant increases, relative to the control group, in walking minutes, F(1, 54) =12.1, p <.001. At the 3-month assessment, amount of time spent in walking activity continued to be significantly higher for the intervention group compared with the control group, F(1, 48) =5.2, p <.05. These findings show that a theoretically based PA Web site and weekly e-mail tip sheets can have a short-term impact on PA motivation and behavior both at 1 and 3 months. As Internet access increases, and as bandwidth and other technical attributes of this medium improve, Web site delivered health behavior interventions will become increasingly useful in public health promotion.

Adult↗

PubMed2002

Environmental factors associated with adults' participation in physical activity: a review.

BACKGROUND: Promoting physical activity is a public health priority, and changes in the environmental contexts of adults' activity choices are believed to be crucial. However, of the factors associated with physical activity, environmental influences are among the least understood. METHOD: Using journal scans and computerized literature database searches, we identified 19 quantitative studies that assessed the relationships with physical activity behavior of perceived and objectively determined physical environment attributes. Findings were categorized into those examining five categories: accessibility of facilities, opportunities for activity, weather, safety, and aesthetic attributes. RESULTS: Accessibility, opportunities, and aesthetic attributes had significant associations with physical activity. Weather and safety showed less-strong relationships. Where studies pooled different categories to create composite variables, the associations were less likely to be statistically significant. CONCLUSIONS: Physical environment factors have consistent associations with physical activity behavior. Further development of ecologic and environmental models, together with behavior-specific and context-specific measurement strategies, should help in further understanding of these associations. Prospective studies are required to identify possible causal relationships.

Adult↗

PubMedDate not supplied

Associations of location and perceived environmental attributes with walking in neighborhoods.

PURPOSE: Ecological models highlight the importance of environmental influences. We examined associations of coastal versus noncoastal location and perceived environmental attributes with neighborhood walking, total walking, and total activity. METHODS: Telephone interviews with 800 faculty and general staff of an Australian university. RESULTS: Men were significantly more likely to walk in their neighborhood if they lived in a coastal location (odds ratio [OR] = 1.66), and they highly rated environmental "aesthetics" (OR = 1.91), "convenience" of facilities (OR = 2.20), and "access" to facilities (OR = 1.98). For women, neighborhood walking was associated with high ratings of "convenience" (OR = 3.78) but was significantly less likely if they had high ratings for "access" (OR = 0.48). For total walking and total physical activity, few significant associations emerged. CONCLUSIONS: Environmental attributes were related to walking in the neighborhood but not to more general activity indices. Understanding gender-specific environmental correlates of physical activity should be a priority.

Australia↗