Appraisal of Clinical Care Practices for Child Obesity Treatment. Part I: Interventions

This technical report was designed to answer 2 overarching key questions: (KQ1) “What are effective clinic-based treatments for pediatric obesity?” and (KQ2) “What is the risk of comorbidities among children with obesity?” We developed this focus based on the needs of clinicians and the evidence required to inform the future development of clinical practice guidelines. This report will not attempt to quantify the magnitude of the effect of obesity on child or adult outcomes. It will also not attempt to address treatment strategies for comorbidities (eg, hypertension), as other guidelines and reviews are available to guide such treatment.^3–6 

In this paper, we report the results for KQ1, intervention studies. Results for KQ2, comorbidity studies, are reported separately.⁷  The 2 components of the review were conducted concurrently, so we present methods for both below.

Clinicians are a trusted source of health information for parents, including issues related to nutrition and physical activity, which are key components of obesity prevention and treatment. Clinicians need to know what strategies have high-quality evidence for effectiveness in preventing and treating obesity. Additionally, clinicians need guidance on which treatments are effective for their patient population and how to leverage available resources for treatment efforts.

Previous recommendations have included assessments of comorbidities, including hypertension, dyslipidemia, glucose, fatty liver disease, and others. It is not clear whether these assessments lead to improved treatment strategies or outcomes. Additionally, it is not clear whether conducting these assessments would result in an adverse patient outcome. We will examine specific conditions that were previously recommended or that would reasonably require screening: dyslipidemia, hypertension, diabetes, fatty liver disease, depression, sleep apnea, and asthma.

We searched Pubmed and CENTRAL (for trials), completing the final search on April 6, 2018. An additional search was conducted to update the review, covering the time period April 7, 2018, through February 15, 2020. We combined the searches for both key questions because of significant overlap and to more efficiently review studies. Because our focus was on interventions that are relevant to primary care, we did not search other discipline-specific databases, such as ERIC or PsycInfo.

The complete search strategies are included in Appendix 2. Briefly, we searched for studies of children or adolescents; with a focus on overweight, obesity, or weight status; involving clinicians, health care, or other treatment or screening (KQ1); and examining common comorbidities (KQ2). For both questions, we limited only using key words, not filters, to ensure we included the newest studies that were not yet fully indexed. No date limits were placed on searches. In practice, this meant we reviewed studies from 1950 to 2020, although <2% were published before 1980.

The complete inclusion criteria are included in Appendix 3.

All studies were required to include children ages 2 to 18 years, although studies could also include young adults up to age 25 years if stratified from older adult participants, as long as children younger than 18 years were also included. Children could have other conditions (eg, asthma), as long as they were not known to cause obesity, such as Prader-Willi syndrome, obesogenic medication (eg, antipsychotics), or known genetic mutations associated with obesity (eg, MC4R). All studies had to originate from Organization for Economic Cooperation and Development (OECD) member countries and had to be available in English.

The primary aim of the intervention studies had to be examination of an obesity prevention (targeting children of any weight status) or treatment intervention (targeting children with overweight or obesity). The primary intended outcome had to be obesity, broadly defined, and not an obesity comorbidity. Studies of obesity interventions that reported only other outcomes were not included. Interventions could be comprised of any approach, including screening, lifestyle counseling, medically managed weight loss, pharmaceutical treatment, or surgery. Regardless of the components, there had to be some level of outpatient clinical involvement in the treatment (ie, not just referral to an outside program), such as screening or a clinic follow-up appointment. Interventions completely outside the scope of health care were excluded. We did not limit based on study design but did report experimental and nonexperimental studies separately. Although we included nonexperimental designs, all studies had to have a relevant comparison group.

See the other technical report on comorbidities⁷  for a detailed description of KQ2 inclusion criteria.

We used Covidence to manage the review process. Covidence is a program for online collaboration and management of systematic reviews. All abstracts were reviewed by 2 independent reviewers for inclusion in full-text review. Articles were reviewed by 2 reviewers, with conflicts discussed and resolved. Articles excluded at this stage were assigned an exclusion reason, with a hierarchy as shown in Appendix 4.

All articles deemed relevant for full text inclusion were categorized into different data extraction strategies. Those given a quality assessment were reviewed using the Cochrane Risk of Bias tool. We chose not to limit studies based on quality, as many did not reach “high quality” using any tools. These studies did not meet “high quality” criteria largely because they were primarily behavioral interventions without the possibility of blinding. All studies, regardless of group, were fully extracted by 2 reviewers, and conflicts were reviewed.

Group 1 articles included randomized trials of diet or lifestyle interventions. “Diet” includes specific meal plans or substitutes, whereas “lifestyle” refers to nonpharmaceutical, nonsurgical intervention and may incorporate nutrition, activity, and other components. Extraction of these articles included sponsorship or funder, design, population information, provider type, detailed intervention strategies and intensity, and BMI-based outcomes. We also identified outcomes other than BMI, including lipids, glucose metabolism, blood pressure, other laboratory values, other obesity measures, psychosocial outcomes, mental health, behaviors, and other outcomes (primarily parent BMI and child cardiovascular fitness). We categorized the intensity of interventions in a manner consistent with the USPSTF, to allow for comparisons with its findings, into <5 hours, 5 to 25 hours, 26 to 51 hours, and 52 or more hours, all over ≤12 months. Quality assessment was conducted for group 1 articles.

Group 2 articles included randomized controlled trials of pharmaceutical treatments. We extracted similar information as above, using a brief description of the intervention and no categorization of intensity. These articles also received a quality assessment.

Group 3 articles included nonrandomized comparative studies of diet and lifestyle interventions. Group 4 articles included nonrandomized comparative studies of pharmaceutical treatment, and Group 5 articles included any surgical studies. Because of small numbers, we combined randomized and nonrandomized surgical studies. Brief intervention descriptions and BMI-related outcome data were extracted from these, but the Cochrane Risk of Bias tool was not used because these were observational designs.

See other report for detailed description of KQ2 extraction procedures.

Our primary method of data synthesis is narrative. To allow broad inclusion, we did not limit to specific designs or measures that would facilitate meta-analysis. We report on studies in each group, based on their type and design, and we report findings for outcomes other than BMI.

A total of 15 988 studies were screened in the title and abstract stage. Of these, 1642 were given a full-text review. Excluded studies (n = 1260) were most commonly not original research, did not compare comorbidities by obesity (KQ2), or were not health-care system based (KQ1). See Fig 1 for the complete PRISMA diagram. Of the 382 studies included, 215 were intervention studies and 167 were comorbidity studies. This report focuses on the 215 intervention studies; the 167 comorbidity studies are reported separately.⁷ 

Of the 215 studies included for KQ1, the majority (n = 126) were randomized trials of lifestyle or diet interventions (group 1), 27 were randomized trials of pharmaceutical treatments (group 2), 43 were observational studies of lifestyle or diet interventions (group 3), 8 were observational studies of pharmaceutical treatment (group 4), and 11 were studies of surgical interventions (group 5). Complete data extraction for all KQ1 studies is available in Appendix 5.

Group 1 studies included 54 with minimal-intervention controls^8–61  and 72 comparative effectiveness studies^62–133  (Table 1). Overall, 35% of the studies demonstrated any difference in BMI SD score (SDS) or BMI attributable to the intervention. There was significant variation in the number of hours of contact among the studies, with an overall increase in the likelihood of any successful weight change as contact hours increased. Detailed summaries of each of these studies are available in Tables 2 and 3.