Evidence of Effectiveness

Intervention strategy examples are sorted based on the strength of evidence for their effectiveness. For the strongest level of evidence (“evidence-based” interventions), examples of commonly used strategies that are rated as having “insufficient evidence” are included in some cases to show the stringency of the evidence-based standard.

The lists are not comprehensive, and the strength of the evidence varies. For interventions that lack evidence, it does not mean they do not work, but that additional research is needed to determine whether or not they are effective.

Communities that are considering carrying out a program to prevent or address obesity need to be aware of tradeoffs associated with the strategies from each level of evidence:

• Evidence-based strategies; strongest evidence
  These intervention approaches have met the most rigorous standards of evidence. Due to the stringency of these standards, many approaches that may have merit do not meet them. The number and range of evidence-based interventions for addressing obesity is extremely small.
• Effective strategies; strong evidence
  These approaches have also been tested in high quality studies. However, it is not always possible to locate effective strategies that have been tested in rural settings, or with special populations such as specific racial and ethnic minority groups that may be concentrated in rural areas.
• Promising and emerging strategies
  These interventions may employ innovative strategies or target populations that have not yet been reached. However, evidence of the effectiveness of the strategy is likely to be limited.

Individual and Policy, Systems, and Environmental (PSE) Interventions
Interventions in this module represent two approaches to addressing obesity. The first type seeks to change the behavior of individuals. The second type addresses social and physical environments (policy, systems, and environmental—or PSE-level change). To clarify the overall approach of the interventions, each one is labeled as targeting either individual-level and/or PSE-level changes:

• Individual change
  Seeks to help individuals reach or maintain a healthy weight by balancing calories taken in through food and calories expended by physical activity. Interventions assist individuals in adopting healthy behaviors like healthy eating and physical activity. While important, such programs have a high per-person cost.
• Policy, Systems, and Environmental (PSE)
  Seeks to help populations maintain healthy weights by making the healthy choice the easy choice. Helps entire populations adopt a healthier lifestyle target PSE-level change. PSE-approaches may use resources more efficiently, but there is less evidence available for their effectiveness.

Testing of Interventions in a Rural Context
Most interventions tested in rural communities target individual change. Few programs targeting PSE changes have been tested in rural communities. Rural practitioners who wish to address environmental barriers to healthy eating and physical activity may need to look at promising or emerging strategies for guidance. More PSE approach models have been tested in school and community settings than in clinics.