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Final Research Plan

Healthful Diet and Physical Activity for Cardiovascular Disease Prevention in Adults Without Known Risk Factors: Behavioral Counseling

May 14, 2015

Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.

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The final Research Plan is used to guide a systematic review of the evidence by researchers at an Evidence-based Practice Center. The resulting Evidence Review forms the basis of the USPSTF Recommendation Statement on this topic.

The draft Research Plan was available for comment from February 19 until March 18, 2015 at 5:00 p.m., ET.

Abbreviations: BMI = body mass index; CVD = cardiovascular disease.

Text Description.

Figure 1 is the analytic framework that depicts the four Key Questions to be addressed in the systematic review. The figure illustrates how behavioral counseling to improve diet, increase physical activity, and reduce sedentary behavior may result in improved health outcomes, including cardiovascular morbidity and mortality, all-cause mortality, and health-related quality of life (KQ 1). Additionally, the figure illustrates how counseling to promote a healthful diet, increased physical activity, and reduced sedentary time may have an impact on intermediate (KQ 2) and behavioral outcomes (KQ 3). Further, the figure depicts whether counseling to promote a healthful diet, increased physical activity, and reduced sedentary time is associated with any adverse events (KQ 4).

  1. Do primary care behavioral counseling interventions to improve diet, increase physical activity, and/or reduce sedentary behavior improve health outcomes in adults?
  2. Do primary care behavioral counseling interventions to improve diet, increase physical activity, and/or reduce sedentary behavior improve intermediate outcomes associated with cardiovascular disease (CVD) in adults?
  3. Do primary care behavioral counseling interventions to improve diet, increase physical activity, and/or reduce sedentary behavior improve associated health behaviors in adults?
  4. What adverse events are associated with primary care behavioral counseling interventions to improve diet, increase physical activity, and/or reduce sedentary behavior in adults?

Contextual questions will not be systematically reviewed and are not shown in the Analytic Framework.

  1. What is the relationship between behavioral outcomes (i.e., healthful diet, physical activity, and sedentary behavior) for which there are evidence that behavioral counseling interventions have an effect and health outcomes (i.e., cardiovascular morbidity and mortality, all-cause mortality, and health-related quality of life)?
  2. What is the relationship between intermediate outcomes (i.e., CVD risk factors) for which there are evidence that behavioral counseling interventions have an effect and health outcomes?

The proposed Research Approach identifies the study characteristics and criteria that the Evidence-based Practice Center will use to search for publications and to determine whether identified studies should be included or excluded from the Evidence Review. Criteria are overarching as well as specific to each of the key questions (KQs).

  Include Exclude
Study aim Primary prevention of CVD
  • Secondary or tertiary prevention of CVD
  • Weight loss*
  • Cancer prevention or treatment
  • Prevention of cognitive decline
  • Prevention of falls
  • Smoking cessation
Condition definition
  • A healthful diet includes dietary patterns that emphasize vegetables, fruits, whole grains, legumes, and nuts; include low-fat dairy products and seafood; limit sodium, saturated fat, refined grains, and sugar-sweetened foods and beverages; and lower amounts of red and processed meats
  • Physical activity is defined as any bodily movement produced by the contraction of skeletal muscle that increases energy expenditure. For the purposes of this review, physical activity includes aerobic and muscle-strengthening physical activity
  • Sedentary behavior refers to behavior characterized by minimal energy expenditure while in a sitting or reclining posture
 Aspects of a healthful diet that are out of scope include:
  • Dietary calcium and other vitamin, micronutrient, and antioxidant supplementation
  • Alcohol moderation

Aspects of physical activity that are out of scope include:

  • Balance
  • Flexibility
  • Gait
Populations Adults age >18 years without known CVD, hypertension, dyslipidemia, impaired fasting glucose/glucose tolerance, and/or smoking, or those who are high risk based on a cardiovascular risk assessment tool, including:
  • Persons who are unselected
  • Persons who have suboptimal behavior (e.g., poor dietary intake, not meeting recommended levels of physical activity, high levels of sedentary time)
  • Persons who are at increased risk for CVD (e.g., due to family history, overweight [BMI of 25.0 to 29.9 kg/m2] or obesity [BMI of ≥30 kg/m2], high-normal blood pressure)
 Studies limited to:
  • Adults with known CVD or diabetes mellitus
  • Adults with other known chronic diseases (e.g., cancer, chronic kidney disease, severe mental illness, cognitive impairment)
  • Adults with known traditional, modifiable CVD risk factors (i.e., hypertension, dyslipidemia, impaired fasting glucose/glucose tolerance, smoking); adults at high risk for CVD based on a cardiovascular risk assessment tool; or trial inclusion criteria specifies that the population has ≥1 CVD risk factors
  • Children and adolescents
  • Parents (if intended behavior change is directed toward children)
  • Pregnant women
  • Institutionalized adults
Settings Conducted in or recruited from primary care or a health care system or could feasibly be implemented in or referred from primary care Conducted in or recruited from settings not generalizable to primary care (e.g., worksites, university classrooms, institutional settings, community-wide settings) or in a population with pre-existing social ties (e.g., from the same worksite or church), or in a setting that could not be reproduced in primary care or within a broader health system
Interventions
  • Behavioral counseling intervention alone or as part of a larger multicomponent intervention on healthful diet and nutrition, physical activity, sedentary behavior, or a combination, including but not limited to: assessment with feedback, advice, collaborative goal-setting, assistance, exercise prescriptions (referral to exercise facility or program), or arranging further contacts
  • Interventions may be delivered via face-to-face contact, telephone, print materials, or technology (e.g., computer-based, text messages) and can be delivered by a number of potential interventionists, including but not limited to: physicians, nurses, exercise specialists, dietitians, nutritionists, and behavioral health specialists
  • Supervised exercise
  • Controlled diet (i.e., feeding trials or providing food to participants)
  • Dietary supplements
  • Stress management interventions (e.g., meditation, yoga, tai chi)
  • Prenatal or postnatal dietary counseling
  • Broader community-based programs (e.g., mass media, social marketing, changes to the community built environment, legislation)
Comparisons
  • No intervention (e.g., wait-list control, usual care)
  • Minimal intervention (e.g., usual care limited to ≤15 minutes of information or pamphlets)
  • Attention control (e.g., similar format and intensity of intervention on a different content area)
  • Active comparators without a control (as defined above)
  • Studies in which the control group is instructed not to exercise
Outcomes KQ 1: Health outcomes (i.e., CVD events [stroke, myocardial infarction], cardiovascular and all-cause mortality, health-related quality of life [physical and mental health–related quality of life])

KQ 2: Intermediate outcomes (e.g., blood pressure, lipid levels, glucose levels, weight, BMI, waist circumference)

KQ 3: Behavioral outcomes (i.e., physical activity, dietary intake or patterns, sedentary behavior)

KQ 4: Adverse outcomes, including any harms requiring unexpected or unwanted medical attention (e.g., nutritional deficiencies, musculoskeletal injuries, cardiovascular events)

 Knowledge, attitudes, and self-efficacy
Timing of outcome assessment KQs 1–3: ≥6 months after baseline

KQ 4: No minimum followup

 KQs 1–3: <6 months after baseline
Countries Studies conducted in countries categorized as “Very High” on the 2014 Human Development Index (as defined by the United Nations Development Programme) Studies conducted in countries that are not categorized as “Very High” on the 2014 Human Development Index
Study designs KQs 1–3: Systematic reviews, individual and cluster RCTs, nonrandomized CCTs

KQ 4: Systematic reviews, RCTs, CCTs, large comparative cohort or case-control studies with appropriate comparison group, large event-monitoring studies

 KQs 1–3: Any observational studies

KQ 4: Ecological studies, case-series, case reports
Publication date Trials whose primary results were published from 1990 to present Trials whose primary results were published prior to 1990
Publication language English Non-English
Study quality Fair or good Poor (according to design-specific USPSTF criteria)

*Studies that focus on the effectiveness of primary care interventions for weight management are included in a separate review commissioned by the USPSTF on screening for and management of adult obesity (available at http://www.uspreventiveservicestaskforce.org/).

Abbreviations: CCT = controlled clinical trial; RCT = randomized, controlled trial.

A draft research plan was posted on the USPSTF Web site for public comment from February 19 to March 18, 2015. The USPSTF received comments from 27 individuals and organizations, with some comments reflecting input of many individuals. The USPSTF made two changes to the research plan based on these comments. The first was to include reduction of sedentary behavior, independent of physical activity, as an intervention and behavioral outcome. The second was to explicitly acknowledge the inclusion of studies among overweight and obese individuals who do not have CVD risk factors. Other minor changes and clarifying text was added as appropriate.