The Task Force finding is based on evidence from a systematic review of 6 studies (search period 1987 - 2003). The review was conducted on behalf of the Task Force by a team of specialists in systematic review methods, and in research, practice, and policy related to increasing physical activity.
There is no information for this section.
Six studies qualified for review and evaluated a variety of effect measures.
- Reviewed studies assessed the relationship between the perceived environment and physical activity practices, or effectiveness in providing a more inviting and safer outdoor environment for activity.
- Overall, the median improvement in some aspect of physical activity (e.g., number of walkers or percent of active individuals) was 35%.
- Additional benefits that may have been brought about by these interventions included:
- Improvements in green space
- Increased sense of community and decreased isolation
- Reductions in crime and stress
- Increased walking and bicycling on urban streets, although beneficial, also pose the risk of increased injury to pedestrian or cyclist, because of increased exposure to motor vehicles.
An economic review of this intervention was not conducted.
This type of intervention is likely to be applicable across diverse settings and population groups, provided appropriate attention is paid to adapting the intervention to the specific setting and target population.
Each Community Preventive Services Task Force (Task Force) review identifies critical evidence gaps—areas where information is lacking. Evidence gaps can exist whether or not a recommendation is made. In cases when the Task Force finds insufficient evidence to determine whether an intervention strategy works, evidence gaps encourage researchers and program evaluators to conduct more effectiveness studies. When the Task Force recommends an intervention, evidence gaps highlight missing information that would help users determine if the intervention could meet their particular needs. For example, evidence may be needed to determine where the intervention will work, with which populations, how much it will cost to implement, whether it will provide adequate return on investment, or how users should structure or deliver the intervention to ensure effectiveness. Finally, evidence may be missing for outcomes different from those on which the Task Force recommendation is based.
Identified Evidence Gaps
Environmental and Policy Approaches
- What characteristics of a community are necessary for the optimal implementation of policy and environmental interventions?
- Does the effectiveness vary by type of access (e.g., worksite facility or community facility) or socioeconomic group?
- How can the necessary political and societal support for this type of intervention be created or increased?
- Does creating or improving access motivate sedentary people to become more active, give those who are already active an increased opportunity to be active, or both?
- If you build it, will they come? In other words, is enhanced access to places for activity sufficient to create higher physical activity levels, or are other intervention activities also necessary?
- What are the effects of creating new places for physical activity versus enhancing existing facilities?
- Which neighborhood features (e.g., sidewalks, parks, traffic flow, proximity to shopping) are the most crucial in influencing activity patterns?
- How does proximity of places such as trails or parks to residence affect ease and frequency
General Research Issues
The following outlines evidence gaps for reviews of these interventions to increase physical activity: Individually-Adapted Health Behavior Change Programs; Social Support Interventions in Community Settings; Family-Based Social Support; Enhanced School-Based Physical Education (archived); College-Based Physical Education and Health Education; Classroom-Based Health Education to Reduce TV Viewing and Video Game Playing; Community-Wide Campaigns; Mass Media Campaigns (archived); Classroom-Based Health Education Focused on Providing Information; Creation of or Enhanced Access to Places for Physical Activity Combined with Informational Outreach Activities.
Several crosscutting research issues about the effectiveness of all of the reviewed interventions remain.
- What behavioral changes that do not involve physical activity can be shown to be associated with changes in physical activity?
- For example, does a decrease in time spent watching television mean an increase in physical activity or will another sedentary activity be substituted?
- Does an increase in the use of public transportation mean an increase in physical activity or will users drive to the transit stop?
- Physical activity is difficult to measure consistently across studies and populations. Although several good measures have been developed, several issues remain to be addressed.
- Reliable and valid measures are needed for the spectrum of physical activity. Rationale: Current measures are better for vigorous activity than for moderate or light activity.
- Sedentary people are more likely to begin activity at a light level; this activity is often not captured by current measurement techniques.
- Increased consensus about “best measures” for physical activity would help to increase comparability between studies and would facilitate assessment of effectiveness.
- Note: This is not intended to preclude researchers’ latitude in choosing what aspects of physical activity to measure and to decide which measures are most appropriate for a particular study population. Perhaps a useful middle ground position would be the establishment of selected core measures that most researchers should use which could then be supplemented by additional measures. The duration of an intervention’s effect was often difficult to determine.
Each recommended and strongly recommended intervention should be applicable in most relevant target populations and settings, assuming that appropriate attention is paid to tailoring. However, possible differences in the effectiveness of each intervention for specific subgroups of the population often could not be determined. Several questions about the applicability of these interventions in settings and populations other than those studied remain.
- Are there significant differences in the effectiveness of these interventions, based on the level or scale of an intervention?
- What are the effects of each intervention in various sociodemographic subgroups, such as age, gender, race, or ethnicity?
Other Positive or Negative Effects
The studies included in this review did not report on other positive and negative effects of these interventions. Research on the following questions would be useful:
- Do informational approaches to increasing physical activity help to increase health knowledge? Is it necessary to increase knowledge or improve attitudes toward physical activity to increase physical activity levels?
- Do these approaches to increasing physical activity increase awareness of opportunities for and benefits of physical activity?
- What are the most effective ways to maintain physical activity levels after the initial behavior change has occurred?
- Are there other benefits from an intervention that might enhance its acceptability? For example, does increasing social support for physical activity carry over into an overall greater sense of community?
- Are there any key harms?
- Is anything known about whether or how approaches to physical activity could reduce potential harms (e.g., injuries or other problems associated with doing too much too fast)?
The available economic data were limited. Therefore, considerable research is warranted on the following questions:
- What is the cost-effectiveness of each of these interventions?
- How can effectiveness in terms of health outcomes or quality-adjusted health outcomes be better measured, estimated, or modeled?
- How can the cost benefit of these programs be estimated?
- How do specific characteristics of each of these approaches contribute to economic efficiency?
- What combinations of components in multicomponent interventions are most cost-effective?
Research questions generated in this review include the following:
- What are the physical or structural (environmental) barriers to implementing these interventions?
- What resource (time and money) constraints prevent or hinder the implementation of these interventions?