Physical Activity: Social Support Interventions in Community Settings

Summary of CPSTF Finding

The Community Preventive Services Task Force (CPSTF) recommends implementing efforts made in community settings to provide social support for increasing physical activity based on strong evidence of their effectiveness in increasing physical activity and improving physical fitness among adults.

Intervention

These social support interventions focus on changing physical activity behavior through building, strengthening, and maintaining social networks that provide supportive relationships for behavior change (e.g., setting up a buddy system, making contracts with others to complete specified levels of physical activity, or setting up walking groups or other groups to provide friendship and support).

CPSTF Finding and Rationale Statement

Read the CPSTF finding.

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About The Systematic Review

The CPSTF finding is based on evidence from a systematic review of 9 studies (search period 1980 – 2000). The review was conducted on behalf of the CPSTF by a team of specialists in systematic review methods, and in research, practice, and policy related to increasing physical activity.

Summary of Results

Nine studies qualified for review.
  • In all nine studies reviewed, social support interventions in community settings were effective in getting people to be more physically active, as measured by various indicators (e.g., blocks walked or flights of stairs climbed daily, frequency of attending exercise sessions, or minutes spent in physical activity).
    • Time spent being physically active: median increase of 44.2% (Interquartile interval [IQI]: 19.9% to 45.6%; 5 study arms)
    • Frequency of physical activity: median increase of 19.6% (IQI: 14.6% to 57.6%; 6 study arms)
    • Aerobic capacity: median net increase in of 4.7% (IQI: 3.3% to 6.1%; 5 study arms)
    • One study found that those who received more frequent support were more active than those who received less frequent support, although both highly structured and less formal support were equally effective.
  • These interventions also improved participants’ fitness levels, lowered their percentage of body fat, increased their knowledge about exercise, and improved their confidence in their ability to exercise.

Summary of Economic Evidence

An economic review of this intervention did not find any relevant studies.

Applicability

Given the diversity of countries, settings, and populations included in this body of evidence, these results should be applicable to diverse settings and populations, provided appropriate attention is paid to adapting the intervention to the target population.

Evidence Gaps

CPSTF identified several areas that have limited information. Additional research and evaluation could help answer the following questions and fill remaining gaps in the evidence base. (What are evidence gaps?)
  • What type of social support and what medium works for whom?
  • Do intensity and structure of the support make a difference?
  • How does effect size vary by frequency of social interaction?
  • Does the effect of these interventions vary by gender?

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.

Effectiveness

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.
Applicability

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)?
Economic Evidence

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?
Barriers

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?

Study Characteristics

  • In the typical intervention, volunteers were grouped to provide companionship and support to help each other reach self-selected activity goals. Study participants received phone calls from other participants and from study staff members to monitor progress and encourage them to continue their activities.
  • Some studies involved formal discussion groups to address barriers to exercise and negative perceptions about activity.
  • Studies were conducted in the United States (7 studies), Canada (1 study), and Australia (1 study).
  • Studies were offered in community settings, including community centers and churches (6 studies), a worksite (1 study), and a university (2 studies).
  • Six studies exclusively or primarily reported results for women, and three studies also included men in their study populations.
  • Study populations for most studies were middle-aged; one study included women aged 18 years or older, and one study focused on women ages 50 to 65 years.
  • Three studies restricted their populations to people who were sedentary at the beginning of the study; the rest included people at any initial level of activity.

Publications

Kahn EB, Ramsey LT, Brownson RC, et al. The effectiveness of interventions to increase physical activity: a systematic review. American Journal of Preventive Medicine 2002;22(4S):73-107.

Task Force on Community Services. Recommendations to increase physical activity in communities. American Journal of Preventive Medicine 2002;22(4S):67-72.

Centers for Disease Control and Prevention. Increasing physical activity. A report on recommendations of the Task Force on Community Preventive Services. MMWR 2001;50(RR-18):1-16. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5018a1.htm.

Roux L, Pratt M, Tengs TO, et al. Cost effectiveness of community-based physical activity interventions. American Journal of Preventive Medicine 2008;35(6):578-88. Available at: http://www.ajpmonline.org/article/S0749-3797(08)00770-8/abstract.

Dunn AL, Blair SN. Translating evidence-based physical activity interventions into practice. American Journal of Preventive Medicine 2002;22(4S):8-9.

Task Force on Community Services, Zaza S, Briss PA, Harris KW. Physical activity. In: The Guide to Community Preventive Services: What Works to Promote Health? Atlanta (GA): Oxford University Press; 2005:80-113.

Analytic Framework

Effectiveness Review

Analytic Framework see Figure 1 on page 76

When starting an effectiveness review, the systematic review team develops an analytic framework. The analytic framework illustrates how the intervention approach is thought to affect public health. It guides the search for evidence and may be used to summarize the evidence collected. The analytic framework often includes intermediate outcomes, potential effect modifiers, potential harms, and potential additional benefits.

Summary Evidence Table

Effectiveness Review

No content is available for this section.

Included Studies

The number of studies and publications do not always correspond (e.g., a publication may include several studies or one study may be explained in several publications).

Effectiveness Review

Avila P, Hovell MF. Physical activity training for weight loss in Latinas: a controlled trial. Int J Obes Relat Metab Disord 1994;18:476 82.

Gill AA, Veigl VL, Shuster JJ, Notelovitz M. A well woman’s health maintenance study comparing physical fitness and group support programs. Occup Therapy J Res 1984;4:286 308.

Jason LA, Greiner BJ, Naylor K, Johnson SP, Van Egeren L. A large-scale, short-term, media-based weight loss program. Am J Health Promot 1991;5:432 7.

King AC, Frederiksen LW. Low-cost strategies for increasing exercise behavior: relapse preparation training and social support. Behav Modif 1984;8:3 21.

King AC, Taylor CB, Haskell WL, Debusk RF. Strategies for increasing early adherence to and long-term maintenance of home-based training in healthy middle-aged men and women. Am J Cardiol 1988;61:628 32.

Kriska AM, Bayles C, Cauley JA, LaPorte RE, Sandler RB, Pambianco G. A randomized exercise trial in older women: increased activity over two years and the factors associated with compliance. Med Sci Sports Exerc 1986;18:557 62.

Lombard DN, Lombard TN, Winett RA. Walking to meet health guidelines: the effect of prompting frequency and prompt structure. Health Psychol 1995;14:164 70.

Simmons D, Fleming C, Voyle J, Fou F, Feo S, Gatland B. A pilot urban church-based programme to reduce risk factors for diabetes among Western Samoans in New Zealand.Diabet Med 1998;15:136 42.

Wankel LM, Yardley JK, Graham J. The effects of motivational interventions upon the exercise adherence of high and low self-motivated adults. Can J Appl Sport Sci 1985;10:147 56.

Additional Materials

Implementation Resource

Rural Health Information Hub, Obesity Prevention Toolkit
This toolkit compiles information, resources, and best practices to support development and implementation of obesity prevention programs in rural communities. Modules include program models, implementation and evaluation resources, and funding and dissemination strategies.

Search Strategies

Effectiveness Review

The search for evidence started with seven computerized databases (MEDLINE, Sportdiscus, Psychlnfo, Transportation Research Information Services [TRIS], Enviroline, Sociological Abstracts, and Social SciSearch) and included reviews of reference lists and consultations with experts in the field. Studies were eligible for inclusion if they:

  • Were published in English during 1980-2000
  • Were conducted in an Established Market Economy*
  • Assessed a behavioral intervention primarily focused on physical activity
  • Were primary investigations of interventions selected for evaluation rather than, for example, guidelines or reviews
  • Evaluated outcomes selected for review; and
  • Compared outcomes among groups of persons exposed to the intervention with outcomes among groups of persons not exposed or less exposed to the intervention (whether the study design included a concurrent or before-and-after comparison)

* Established Market Economies as defined by the World Bank are Andorra, Australia, Austria, Belgium, Bermuda, Canada, Channel Islands, Denmark, Faeroe Islands, Finland, France, Germany, Gibraltar, Greece, Greenland, Holy See, Iceland, Ireland, Isle of Man, Italy, Japan, Liechtenstein, Luxembourg, Monaco, the Netherlands, New Zealand, Norway, Portugal, San Marino, Spain, St. Pierre and Miquelon, Sweden, Switzerland, the United Kingdom, and the United States.

Economic Review

The databases MEDLINE, Transportation Research Information Services (TRIS), Combined Health Information Database (CHID), ECONLIT, PsychInfo, Sociological Abstracts, Sociofile, Social SciSearch, and Enviroline were searched for the period 1980 2000. In addition, the references listed in all retrieved articles were reviewed and experts were consulted. Most of the included studies were either government reports or were published in journals. To be included in the review a study had to:

  • Be a primary study rather than, for example, a guideline or review
  • Take place in an Established Market Economy
  • Be written in English
  • Meet the team’s definitions of the recommended and strongly recommended interventions
  • Use economic analytical methods such as cost analysis, cost-effectiveness analysis, cost-utility, or cost-benefit analysis; and
  • Itemize program costs and costs of illness or injury averted

Considerations for Implementation

The following considerations are drawn from studies included in the evidence review, the broader literature, and expert opinion.
  • Included studies reported favorable effects of the intervention on adiposity, confidence about exercise, and knowledge of and social support for exercise.