Final Research Plan

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

June 04, 2020

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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Figure 1 is the analytic framework that depicts the four Key Questions to be addressed in the systematic review. The figure illustrates how counseling interventions for adults without known cardiovascular disease (CVD) risk factors (hypertension or elevated blood pressure, dyslipidemia or elevated lipids, impaired fasting glucose or impaired glucose tolerance, and mixed or multiple risk factors) may result in improved health outcomes (cardiovascular events and related morbidity, cardiovascular and all-cause mortality, and quality of life measures) (Key Question 1). Additionally, the figure illustrates how counseling interventions for adults without known CVD risk factors may have an impact on intermediate outcomes (change in CVD risk factors: blood pressure, lipids, blood glucose, cardiorespiratory fitness, body mass index, weight, waist circumference, dichotomized versions of CVD risk factors, and calculated 10-year CVD risk) (Key Question 2) and intermediate behavioral outcomes (dietary intake, physical activity, and sedentary behavior) (Key Question 3). There is also a question related to potential harms resulting from counseling interventions for adults without known CVD risk factors (Key Question 4).

*CVD risk factors include hypertension or elevated blood pressure, dyslipidemia or elevated lipid levels, impaired fasting glucose or impaired glucose tolerance, and mixed or multiple risk factors (e.g., 10-year CVD risk >7.5% and metabolic syndrome).

Abbreviations: BP=blood pressure; BMI=body mass index; CVD=cardiovascular disease; yr=year.

  1. Do primary care–relevant behavioral counseling interventions to improve diet, increase physical activity, and reduce sedentary behavior improve cardiovascular disease (CVD) and related health outcomes (e.g., morbidity and mortality) in adults without known CVD risk factors*?
  2. Do primary care–relevant behavioral counseling interventions to improve diet, increase physical activity, and reduce sedentary behavior improve intermediate outcomes associated with CVD (g., blood pressure, lipid levels, blood glucose levels, and body mass index) in adults without known CVD risk factors*?
  3. Do primary care–relevant behavioral counseling interventions to improve diet, increase physical activity, and reduce sedentary behavior improve intermediate behavioral outcomes (e.g., diet, physical activity, and sedentary behavior) in adults without known CVD risk factors*?
  4. What are the harms of primary care–relevant behavioral counseling interventions to improve diet, increase physical activity, and reduce sedentary behavior in adults without known CVD risk factors*? 

*CVD risk factors include hypertension or elevated blood pressure, dyslipidemia or elevated lipid levels, impaired fasting glucose or impaired glucose tolerance, and mixed or multiple risk factors (e.g., 10-year CVD risk >7.5% and metabolic syndrome)

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

  1. What is the relationship between intermediate behavioral outcomes (i.e., diet and physical activity) and health outcomes (i.e., cardiovascular morbidity and mortality, all-cause mortality, and quality of life)?
  2. What is the relationship between intermediate outcomes (i.e., blood pressure, low- and high-density lipoprotein levels, and fasting glucose levels) and health outcomes?

The 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.

  Include Exclude
Study aim Primary prevention of CVD
  • Secondary or tertiary prevention of CVD
  • Weight loss or weight loss maintenance*
  • Cancer prevention or treatment
  • Prevention or treatment of diabetes
  • Prevention or treatment of cognitive decline
  • Prevention of falls
  • Smoking cessation
  • Management of other diseases or conditions (e.g., managing symptoms associated with arthritis)
Populations Adults age >18 years without known CVD risk factors†

Includes studies among the following populations:

  • Adults who are unselected
  • Adults selected based on suboptimal behavior (e.g., poor dietary intake, not meeting recommended levels of physical activity, or high levels of sedentary time)
  • Adults who do not have known CVD risk factors† but whom may otherwise be at increased risk for CVD (i.e., based on age, sex, race/ethnicity, family history, or excess weight [BMI ≥25.0 kg/m2])
 Studies limited to:
  • Children and adolescents
  • Parents (if intended behavior change is directed toward children)
  • Persons with known CVD or diabetes mellitus
  • Persons with known traditional CVD risk factors (i.e., hypertension or elevated blood pressure, dyslipidemia or elevated lipid levels, impaired fasting glucose or impaired glucose tolerance, and 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
  • Current smokers
  • Persons with medical conditions limiting their generalizability to primary care–based populations (e.g., persons with acute illnesses, cognitive impairment, severe and persistent mental illness, cancer or cancer survivors, or chronic pain)
  • Pregnant women
  • Adults in institutions
Settings
  • Studies conducted in or recruited from primary care or a health care system or could feasibly be implemented in or referred from primary care. For an intervention to be feasible for primary care or primary care referral, it would need to be conducted in a health care setting or be available for referral in the community, including electronically-delivered and community-based interventions.
  • Studies conducted in countries rated as “very high” on the Human Development Index (based on 2018 indicators and as defined by the United Nations Development Programme)
 Studies conducted in or recruited from settings not generalizable to primary care (e.g., inpatient hospital units, emergency departments, nursing homes and other institutionalized settings, school classroom–based programs, occupational settings)
Interventions

Behavioral counseling intervention alone or as part of a larger multicomponent intervention on 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), and arranging further contacts. Interventions may be delivered via face-to-face contact, telephone, print materials, or technology (e.g., computer-based, text messages, and remote video feed) 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

Dietary counseling may include focus on:

  • Increased consumption of fruits, vegetables, whole grains, fat-free or low-fat dairy, and lean proteins
  • Limited consumption of sodium, saturated fat, trans fat, and sugar-sweetened food and beverages

Physical activity counseling may include focus on:

  • Aerobic activities that involve repeated use of large muscles, such as walking, cycling, and swimming
  • Resistance or strength training
  • Optional or access to guided physical activity or exercise classes allowed

Sedentary behavior counseling may include focus on:

  • Reduced sitting time
  • Breaking up short periods of sedentary time

Limited guided physical activity or provision of food samples allowed if intention is to teach or demonstrate healthy lifestyle principles
  • Noncounseling interventions (e.g., use of incentives, supervised exercise with the goal of assessing effects of exercise, or controlled diets)
  • Dietary counseling solely focused on increasing specific vitamins, micronutrients, or antioxidants through dietary change or supplementation, or focused on alcohol moderation
  • Physical activity counseling solely focused on balance, flexibility, or gait
  • Stress management interventions (e.g., meditation-, yoga-, or tai chi–based interventions that have minimal aerobic or strength-building activities)
  • Prenatal or postnatal dietary counseling
  • Counseling interventions with components that are not feasible for implementation in healthcare settings (e.g., occupational/worksite-, church-, or school-based interventions that are conducted within existing social networks; social marketing [e.g., media campaigns]; or policy [e.g., local or state public/health policy])
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 in inclusion criteria)
  • Studies in which the control group is instructed to not change their diet, physical activity, or sedentary behavior
Outcomes KQ 1: Health outcomes
  • Cardiovascular events and related morbidity (e.g., stroke, myocardial infarction, or heart failure)
  • Cardiovascular and all-cause mortality
  • Quality of life measures and related outcomes (e.g., functioning or well-being)

KQ 2: Intermediate outcomes

  • Blood pressure
  • Total, low-density lipoprotein, and high-density lipoprotein cholesterol
  • Hemoglobin A1c, fasting glucose levels, and 1- and 2-hour glucose tolerance test results
  • Body mass index, weight, and waist circumference
  • Cardiorespiratory fitness (e.g., vo2max, heart rate, exercise tolerance, or 6-minute walk)
  • Dichotomized versions of CVD risk factors (hypertension, dyslipidemia, diabetes mellitus, overweight or obesity, or incidence of metabolic syndrome)
  • Calculated 10-year CVD risk

KQ 3: Behavioral outcomes

  • Dietary intake or patterns
  • Physical activity
  • Sedentary behavior

KQ 4: Harms

  • Harms occurring following the intervention (e.g., nutritional deficiencies, disordered eating, symptoms of anxiety, musculoskeletal injuries, or cardiovascular events)
  • Knowledge, attitudes, and self-efficacy
  • Mental health symptom scores
  • Balance or flexibility
Timing of outcome assessment ≥6 months postbaseline <6 months postbaseline
Study designs Randomized, clinical trials and nonrandomized controlled intervention studies Observational study designs (including prospective and retrospective cohort studies, before-after studies, interrupted time series studies, repeated measures studies, case-control studies, and case series)
Publication language English Languages other than 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 Behavioral Weight Loss Interventions to Prevent Obesity-Related Morbidity and Mortality in Adults (https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/obesity-in-adults-interventions).

†Persons with known traditional CVD risk factors (i.e., hypertension or elevated blood pressure, dyslipidemia or elevated lipid levels, and impaired fasting glucose or glucose tolerance); 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.

Abbreviations: CVD=cardiovascular disease; KQ=key question; USPSTF=U.S. Preventive Services Task Force; vo2max=maximum rate of oxygen consumption.