Draft Research Plan

Weight Loss to Prevent Obesity-Related Morbidity and Mortality in Adults: Behavioral Interventions

December 10, 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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Abbreviation: HRQoL=health-related quality of life.

Text Description.

Figure 1 is the analytic framework that depicts the three Key Questions to be addressed in the systematic review. The figure illustrates how behavioral counseling or pharmacotherapy interventions for weight loss or weight loss maintenance may result in improved health outcomes, including obesity-related morbidity and mortality and health-related quality of life (KQ1). Additionally, the figure illustrates how behavioral counseling or pharmacotherapy interventions for weight loss or weight loss maintenance may have an effect on intermediate outcomes (including weight loss and the incidence or prevalence of obesity-related conditions) (KQ2). Further, the figure depicts whether behavioral counseling or pharmacotherapy interventions for weight loss or weight loss maintenance are associated with any adverse events (KQ4).

  1. Do primary care–relevant behavioral or pharmacotherapy interventions for weight loss and weight loss maintenance lead to improved health outcomes in adults who are overweight or obese and candidates for weight loss interventions?
  2. Do primary care–relevant behavioral or pharmacotherapy interventions for weight loss and weight loss maintenance lead to weight loss, weight loss maintenance, or a reduction in the incidence or prevalence of obesity-related conditions in adults who are overweight or obese and candidates for weight loss interventions?
  3. What are the adverse effects of primary care–relevant behavioral or pharmacotherapy interventions for weight loss and weight loss maintenance in adults who are overweight or obese and candidates for weight loss interventions?

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

  1. Does the predictive value of the body mass index (BMI) for future mortality and health risks differ by population subgroup (i.e., specific racial/ethnic subgroups, older adults)?
  2. Does primary care–feasible assessment of central adiposity increase the predictive value of BMI for future mortality and health risks?
  3. What health effects (i.e., mortality or incidence of cardiovascular disease, type 2 diabetes mellitus, or cancer) are associated with intentional weight loss and/or BMI reduction?

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 Weight loss or weight loss maintenance
  • Primary prevention of overweight or obesity
  • Treatment of cardiovascular disease
  • Diabetes management*
  • Treatment of cancer
Condition definition Overweight or obesity, as defined by BMI or other weight-related measurements  
Populations
  • Adults age ≥18 years who are candidates for weight loss or weight loss maintenance interventions selected based on an above normal BMI (e.g., ≥25 kg/m2) or other weight-related measure (e.g., waist circumference)
  • Patients may or may not have additional risk factors, including hypertension, dyslipidemia, or impaired glucose tolerance/fasting glucose (i.e., prediabetes)

Studies limited to:

  • Populations not selected based on weight-related measures
  • Adults with secondary causes of obesity, such as steroid use
  • Adults with chronic diseases in which weight loss/maintenance is part of disease management (e.g., osteoarthritis, known cardiovascular disease, diabetes mellitus, polycystic ovary syndrome, sleep apnea)
  • Adults with known chronic diseases that are not generalizable to the primary care population (e.g., eating disorder, cancer, chronic kidney disease, severe mental illness, cognitive impairment)
  • Children and adolescents
  • Parents (if intended behavior change is directed toward children)
  • Pregnant or postpartum women
  • Adults who are institutionalized
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
  • In order for an intervention to be feasible for primary care referral, it would need to be conducted as part of a health care setting or be widely available in the community at a national level (e.g., commercial weight loss programs, technology interventions)
 Studies conducted in or recruited from settings not generalizable to primary care (e.g., worksites, university classrooms, institutional settings), in a population with pre-existing social ties (e.g., from the same worksite or church), or in a setting where the intervention could not be reproduced in primary care or within a broader health system
Interventions Interventions focusing on weight loss or weight loss maintenance, including the following:
  • 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), arranging further contacts, or provider training
  • Pharmacologic interventions that are approved by the U.S. Food and Drug Administration as first-line, long-term weight loss or weight management medications:
    • Orlistat
    • Lorcaserin hydrochloride
    • Phentermine-topiramate extended release
    • Naltrexone hydrochloride and bupropion hydrochloride
    • Liraglutuide
  • Combination of these interventions

Interventions may be delivered via face-to-face contact, telephone, print materials, or technology (e.g., computer-based, text messages) and by a number of potential interventionists, including but not limited to: physicians, nurses, exercise specialists, dietitians, nutritionists, and behavioral health specialists
  • Surgical procedures (laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, biliopancreatic diversion with duodenal switch, sleeve gastrectomy)
  • Nonsurgical devices and procedures (balloon system, vagus nerve stimulation)
  • Medications that are not approved by the U.S. Food and Drug Administration as long-term weight loss agents, including new agents currently under evaluation (e.g., leptin, peptide YY, oxyntomodulin, melanocortin-4 receptor agonists), agents taken off the market (e.g., fenfluramine, dexfenfluramine, sibutramine), and agents only approved for short-term weight loss (e.g., diethylpropion, phentermine, benzphetamine, phendimetrazine)
  • Medications that are only indicated for the treatment of type 2 diabetes (e.g., metformin, pramlintide, empagliflozin, albiglutide, dulaglutide, alogliptin, exenatide)
  • Complementary and alternative treatments (e.g., acupuncture, mindfulness)
  • Dietary supplements intended for weight loss (e.g., chitosan, guar gum, chromium, ginseng, glucomannan, green tea, hydroxycitric acid, L-carnitine, psyllium, pyruvate supplements, St. John’s wort, and conjugated linoleic acid)
  • Health care system interventions
  • Broader community-based programs (e.g., mass media, social marketing, changes to the community built environment, legislation)
Comparisons For studies of behavioral interventions:
  • No treatment (e.g., wait-list control, usual care)
  • Attention control (e.g., similar format and intensity of intervention but on a different content area)
  • Minimal intervention comparable to usual care (including use of generic print/electronic communications)

For studies of pharmacologic interventions:

  • Placebo
  • Two groups must participate in identical behavioral intervention component
 For studies of behavioral interventions: Active comparators without a control (as defined in the inclusion criteria)

For studies of pharmacologic interventions: Comparison of different pharmacological interventions
Outcomes KQ 1: Health outcomes:
  • Mortality
  • Morbidity (e.g., diabetic amputation, hypertensive nephrosclerosis)
  • Depression
  • Emotional functioning, as measured by mental subscales of quality of life instruments
  • Physical functioning, as measured by physical subscales of quality of life measures
  • Disability measures (global measures only, such as activities of daily living)

KQ 2: Weight outcomes (required for study to be included) and incidence or prevalence of related conditions:

  • Measured weight (e.g., kilograms, pounds)
  • Relative weight (e.g., BMI, % overweight, % obese)
  • Total adiposity (e.g., dual-energy x-ray absorptiometry, underwater weighing)
  • Central adiposity (e.g., waist circumference, waist-to-hip circumference ratio)
  • Weight maintenance
  • Incidence or prevalence of obesity-related conditions (e.g., diabetes mellitus, hypertension, dyslipidemia, cardiovascular disease, sleep apnea)

KQ 3: Adverse outcomes

  • Serious treatment-related harms at any time point after an intervention began (i.e., death, medical issue requiring hospitalization or urgent medical treatment, inducement of an eating disorder)
  • Discontinuation of medication due to adverse effects
 KQ 1:
  • Functioning (except as enumerated under health outcomes)
  • Cost-effectiveness
  • Behavioral changes (e.g., physical activity, diet, smoking)

KQ 2: Cardiometabolic measures (e.g., glucose levels, blood pressure, lipid levels)
Timing of outcome assessment KQs 1, 2: ≥12 months after start of intervention or baseline assessment (if the intervention start cannot be determined)

KQ 3: No minimum followup

 KQs 1, 2: <12 months after baseline
Countries Studies conducted in economically developed countries, defined as member countries (2015) of the Organisation for Economic Co-Operation and Development (i.e., Australia, Austria, Belgium, Canada, Chile, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Korea, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom, United States)
  • Studies conducted in countries with populations not similar to the United States
  • Studies conducted in countries that are not a member of the Organisation for Economic Co-Operation and Development
Study designs KQs 1, 2: Randomized or controlled clinical trials, including cluster randomized trials

KQ 3:

  • Systematic reviews, including meta-analyses, of randomized or controlled clinical trials or cohort studies
  • Randomized or controlled clinical trials, including cluster randomized trials
  • Large cohort or case-control studies reporting serious adverse effects related to weight loss interventions
 KQs 1, 2: Any observational studies, ecological studies, case reports, case series, or other noncomparative reviews or letters to the editor

KQ 3: Ecological studies, case-series, and case reports
Publication language English Languages other than English
Study quality Fair or good (according to design-specific USPSTF criteria) Poor (according to design-specific USPSTF criteria)

* Studies that focus on the effectiveness of primary care interventions for the primary prevention of cardiovascular disease or treatment of diabetes are included in separate reviews commissioned by the USPSTF (available at www.uspreventiveservicestaskforce.org).