The role and theoretical evolution of knowledge translation and exchange in public health

Background There is an increased emphasis in public health research on effective models and strategies to support knowledge translation (KT), the exchange, synthesis and ethically sound application of research findings within a complex set of interactions among researchers and knowledge users. In other words, KT can be seen as an acceleration of the knowledge cycle—an acceleration of the natural transformation of knowledge into use (Canadian Institutes of Health Services Research. Knowledge Translation Strategy, 2004). The most recent conceptualizations consider the complexities of public health decision-making. The role of practitioners and communities is increasingly considered.

Methods We identify, describe and discuss the theoretical underpinnings of KT and recommend a way forward to build the evidence for more effective practice.

Results Theoretical perspectives increasingly influence research on KT in public health. A range of innovative work is being conducted to explore methods for KT using practical tools, often with the support of government.

Conclusions KT describes a crucial and to date under-developed element of the research process. There is an important gap in theoretically informed empirical studies of effectiveness of proposed approaches in public health, health promotion and preventive medicine, and thus much of the debate remains abstract. There is clearly an urgent policy need to establish the effectiveness of KT models in a range of contexts. This must include both the consideration of development and the utilization of knowledge.

Neighborhood walkability and the walking behavior of Australian adults

Background
The physical attributes of residential neighborhoods, particularly the connectedness of streets and the proximity of destinations, can influence walking behaviors. To provide the evidence for public health advocacy on activity-friendly environments, large-scale studies in different countries are needed. Associations of neighborhood physical environments with adults’ walking for transport and walking for recreation must be better understood.

Method
Walking for transport and walking for recreation were assessed with a validated survey among 2650 adults recruited from neighborhoods in an Australian city between July 2003 and June 2004, with neighborhoods selected to have either high or low walkability, based on objective measures of connectedness and proximity derived from geographic information systems (GIS) databases. The study design was stratified by area-level socioeconomic status, while analyses controlled for participant age, gender, individual-level socioeconomic status, and reasons for neighborhood self-selection.

Results
A strong independent positive association was found between weekly frequency of walking for transport and the objectively derived neighborhood walkability index. Preference for walkable neighborhoods moderated the relationship of walkability with weekly minutes, but not the frequency of walking for transport—walkability was related to higher frequency of transport walking, irrespective of neighborhood self-selection. There were no significant associations between environmental factors and walking for recreation.

Conclusions
Associations of neighborhood walkability attributes with walking for transport were confirmed in Australia. They accounted for a modest but statistically significant proportion of the total variation of the relevant walking behavior. The physical environment attributes that make up the walkability index are potentially important candidate factors for future environmental and policy initiatives designed to increase physical activity.

Neighborhood walkability and TV viewing time among Australian adults

Background
Built-environment attributes of a neighborhood are associated with participation in physical activity and may also influence time spent in sedentary behaviors. Associations of neighborhood walkability (based on dwelling density, street connectivity, land-use mix, and net retail area) and television viewing time were compared in a large, spatially-derived sample of Australian adults.

Methods
Neighborhood-level variables (walkability and socioeconomic status [SES]) were calculated in 154 Australian census collection districts using Geographic Information Systems. Individual-level variables (TV viewing time, time spent in leisure-time physical activity, height, weight, and sociodemographic variables) were collected from adults living in urban areas of Adelaide, Australia using a mail survey (N=2224) in 2003–2004. Multilevel linear regression analysis was conducted in 2006 separately for men and women to examine variations in TV viewing time across tertiles of walkability.

Results
Neighborhood walkability was negatively associated with TV viewing time in women, but not in men. After controlling for neighborhood SES, body mass index, physical activity, and sociodemographic variables, women living in medium- and high-walkable neighborhoods reported significantly less TV viewing time per day (14 minutes and 17 minutes, respectively) compared to those residing in low-walkable neighborhoods.

Conclusions
Built-environment attributes of neighborhoods that are related to physical activity also may play an important role in influencing sedentary behavior, particularly among women. Considering the effects of prolonged sedentary time on health risks, which are independent of physical activity, there is the need for further research to explore how environmental characteristics may contribute to the amount of time spent in sedentary behavior.

Perceived environment attributes, residential locaction, 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.

Print versus website physical activity programs: a randomized trial.

Background: Mediated physical activity interventions can reach large numbers of people at low cost. Programs delivered through the mail that target the stage of motivational readiness have been shown to increase activity. Communication technology (websites and e-mail) might provide a means for delivering similar programs. Methods: Randomized trial conducted between August and October 2001. Participants included staff at an Australian university (n=655; mean AGE=43, standard deviation, 10 years). Participants were randomized to either an 8-week, stage-targeted print program (Print) or 8-week, stage-targeted website (Web) program. The main outcome was change in self-reported physical activity. Results: There was no significant increase in total reported physical activity within or between groups when analyzed by intention to treat (F [1,653]=0.41, p=0.52). There was a significant increase in total physical activity reported by the Print participants who were inactive at baseline (t [1,173]=−2.21, p=0.04), and a significant decrease in the average time spent sitting on a weekday in the Web group (t [1,326]=2.2, p=0.03). Conclusions: There were no differences between the Print and Web program effects on reported physical activity. The Print group demonstrated slightly larger effects and a higher level of recognition of program materials.

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.

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.

Preschool children and physical activity : a review of correlates

Background
Several reviews have summarized the research on correlates of older children's and adolescents' physical activity behaviors, but none have been published on preschool children. Over the past 27 years, a number of studies have investigated the correlates of preschool children's physical activity behaviors. It is timely and necessary to review the extant literature in this area. This paper reviews articles investigating correlates of preschool children's physical activity behaviors published in peer-reviewed journals between 1980 and March 2007.

Methods
A literature search was conducted to identify studies that investigated correlates of preschool children's physical activity. Data were collected and analyzed in 2007.

Results
Twenty-four articles were identified that met the inclusion criteria. From those articles, 39 variables were identified across five domains. Results showed that boys were more active than girls, that children with active parents tended to be more active, and that children who spent more time outdoors were more active than children who spent less time outdoors. Age and BMI were consistently shown to have no association with preschool children's physical activity. Other variables produced largely inconclusive results.

Conclusions
The influences on the physical activity behaviors of preschool children are multidimensional. Further research is required to enhance an understanding of these influences.

Walking and cycling to school : predictors of increases among children and adolescents

Background
Little is known about what happens to active commuting as children get older, and less is known about influences on changes in this behavior. This study examined predictors of increases in children's and adolescents' active commuting (walking or cycling) to/from school over a 2-year period.
Methods
Participants were initially recruited and assessed in 2001. Follow-up data were collected in 2004 and 2006 and analyzed in 2008. Participants were 121 children (aged 9.1±0.34 years in 2004) and 188 adolescents (aged 14.5±0.65 years in 2004) from Melbourne, Australia. Parents and adolescents reported their perceptions of individual-level factors and of the neighborhood social and physical environment. Weekly active commuting (walking or cycling) to/from school, ranging from 0 to 10 trips/week was also proxy- or self-reported at the initial measurement and again 2 years later. Logistic regression analyses examined predictors of increases in active commuting over time.
Results
Children whose parents knew many people in their neighborhood were more likely to increase their active commuting (OR=2.6; CI=1.2, 5.9; p=0.02) compared with other children. Adolescents whose parents perceived there to be insufficient traffic lights and pedestrian crossings in their neighborhood were less likely to increase their active commuting over 2 years (OR=0.4; CI=0.2, 0.8; p=0.01), whereas adolescents of parents who were satisfied with the number of pedestrian crossings were more likely to increase their active commuting (OR=2.4; CI=1.1, 5.4; p=0.03) compared with other adolescents.
Conclusions
Social factors and physical environmental characteristics were the most important predictors of active commuting in children and adolescents, respectively.

The lifestyle of our kids (LOOK) project : outline of methods

This methods paper outlines the overall design of a community-based multidisciplinary longitudinal study with the intent to stimulate interest and communication from scientists and practitioners studying the role of physical activity in preventive medicine. In adults, lack of regular exercise is a major risk factor in the development of chronic degenerative diseases and is a major contributor to obesity, and now we have evidence that many of our children are not sufficiently active to prevent early symptoms of chronic disease. The lifestyle of our kids (LOOK) study investigates how early physical activity contributes to health and development, utilizing a longitudinal design and a cohort of eight hundred and thirty 7–8-year-old (grade 2) school children followed to age 11–12 years (grade 6), their average family income being very close to that of Australia. We will test two hypotheses, that (a) the quantity and quality of physical activity undertaken by primary school children will influence their psychological and physical health and development; (b) compared with existing practices in primary schools, a physical education program administered by visiting specialists will enhance health and development, and lead to a more positive perception of physical activity. To test the first hypothesis we will monitor all children longitudinally over the 4 years. To test the second we will involve an intervention group of 430 children who receive two 50 min physical education classes every week from visiting specialists and a control group of 400 who continue with their usual primary school physical education with their class-room teachers. At the end of grades 2, 4, and 6 we will measure several areas of health and development including blood risk factors for chronic disease, cardiovascular structure and function, physical fitness, psychological characteristics and perceptions of physical activity, bone structure and strength, motor control, body composition, nutritional intake, influence of teachers and family, and academic performance.

Identifying subgroups of U.S. adults at risk for prolonged television viewing to inform program development

Background
Although adverse health effects of prolonged TV viewing have been increasingly recognized, little population-wide information is available concerning subgroups at greatest risk for this behavior.

Purpose
This study sought to identify, in a U.S. population–derived sample, combinations of variables that defined subgroups with higher versus lower levels of usual TV-viewing time.

Methods
A total of 5556 adults from a national consumer panel participated in the mail survey in 2001 (55% women, 71% white, 13% black, and 11% Hispanic). Nonparametric risk classification analyses were conducted in 2008.

Results
Subgroups with the highest proportions of people watching >14 hours/week of TV were identified and described using a combination of demographic (i.e., lower household incomes, divorced/separated); health and mental health (i.e., poorer rated overall health, higher BMI, more depression); and behavioral (i.e., eating dinner in front of the TV, smoking, less physical activity) variables. The subgroup with the highest rates of TV viewing routinely ate dinner while watching TV and had lower income and poorer health. Prolonged TV viewing also was associated with perceived aspects of the neighborhood environment (i.e., heavy traffic and crime, lack of neighborhood lighting, and poor scenery).

Conclusions
The results can help inform intervention development in this increasingly important behavioral health area.

The concept of prevention : a good idea gone astray?

Over time, the definition of prevention has expanded so that its meaning in the context of health services is now unclear. As risk factors are increasingly considered to be the equivalent of “diseases” for purposes of intervention, the concept of prevention has lost all practical meaning. This paper reviews the inconsistencies in its utility, and suggests principles that it should follow in the future: a population orientation with explicit consideration of attributable risk, the setting of priorities based on reduction in illness and avoidance of adverse effects, and the imperative to reduce inequities in health.