The landscape of feeding recommendations is vast and heterogeneous. Identifying and characterizing all feeding guidance that exists for infants and young children, both nationally and globally, is not feasible. To that end, the committee sought to explore current guideline documents from government agencies and from authoritative professional and nonprofit organizations, with a focus on guidance relevant to healthy mother–infant
dyads in high-income countries (for rationale, see Chapter 1). The sections that follow provide an overview of the process the committee undertook to identify and compare the collection of guideline documents referenced throughout the remainder of the report.
To identify potentially relevant documents, the committee conducted searches as outlined in Figure 2-1 and described in detail below. Searches were intended to be broadly inclusive of any materials that contained feeding recommendations for healthy, term infants and young children from birth to 24 months, relevant to high-income countries. The committee did not establish any other criteria for the guideline materials during the initial searches.
Targeted Website Searches
Recognizing that guideline documents and resources likely exist in the gray literature and may not be cataloged in databases, the primary approach for identifying guideline documents consisted of targeted website searches. The committee first created a list of potentially relevant government agencies, professional organizations, nonprofit organizations, and international groups. Using a snowball search approach, other agencies and organizations were added to the list when, over the course of a targeted website search, they were noted as a source of additional information. Agencies, groups, and organizations that ultimately did not qualify as authoritative were still searched, as their websites often provided links to primary guideline documents and resources within and beyond their organizations.
Website searches began on the homepage for each organization. The search strategy depended on the website structure; dropdown menus, topic area groupings, and document search options were used to find potentially relevant guideline documents. Staff conducted targeted website searches during the last 2 weeks of November 2019. Given resource constraints, duplicate searches were only conducted when the first search did not yield any results. The committee acknowledges that this approach may have led to the inadvertent omission of some eligible documents. The other search approaches (i.e., food-based dietary guideline search, expert input, and database searches) were intended to supplement the targeted website searches, and help to fill in potential gaps.
Food-Based Dietary Guideline Search
The Food and Agriculture Organization of the United Nations maintains a website that catalogs national food-based dietary guidelines and
food guides (FAO, 2019). This catalog was used to search for English-language documents from high-income countries that included feeding recommendations relevant to infants and young children. National food-based dietary guidelines and related resources from eight countries were included for screening (see Figure 2-2).
Members of the committee contacted international experts about English-language versions of national feeding guideline documents and supporting materials from Denmark, Germany, Italy, and Norway. Documents available in English were included in the committee’s screening process. The committee also took advantage of its expertise to identify potentially relevant resources not identified through other search approaches.
As an adjunct to its targeted website searches, the following databases were used to search for relevant guideline documents: CPG Infobase, ECRI Institute Guideline Trust, International Guideline Library, GuidelineCentral, NICE Evidence Search, and PubMed. The search strategy was developed with the assistance of a senior librarian and was carried out by staff (see Table 2-1). Filters were used for language, publication type, age group, and publication date as available within each database. Searches included documents published through the first week of December 2019. Title and abstract screening from these searches was not conducted in duplicate owing to resource limitations. The committee acknowledges that this approach may have led to the inadvertent omission of some eligible documents.
|Name||Selected Filters||Search Term||Number of Results||Number Included for Screeninga|
|CPG Infobase: Clinical Practice Guidelinesb||
|baby OR babies||0||0|
|“breast milk” OR breastmilk||30||4|
|breastfeed* OR breastfed* OR “breast feed*” OR “breast fed*”||0||0|
|Name||Selected Filters||Search Term||Number of Results||Number Included for Screeninga|
|ECRI Institute Guideline Trustc||
|baby OR babies||8||0|
|“breast milk” OR breastmilk||2||2|
|breastfeed* OR breastfed* OR “breast feed*” OR “breast fed*”||6||2|
|International Guideline Libraryd||
|baby OR babies||4||0|
|“breast milk” OR breastmilk||1||0|
|breastfeed* OR breastfed* OR “breast feed*” OR “breast fed*”||9||2|
|Name||Selected Filters||Search Term||Number of Results||Number Included for Screeninga|
|NICE evidence searchf,g||
|“breast milk” OR breastmilk||254||14|
|breastfeed* OR breastfed* OR “breast feed*” OR “breast fed*”||631||18|
|“child nutrition” OR “infant nutrition”||62||11|
|“breast milk” or breastmilk||18||4|
|breastfeeding OR “breast feeding” OR breastfeed OR “breast feed” OR breastfed OR “breast fed” OR “Breast Feeding”[Mesh]||222||12|
|“complementary feeding” OR “Infant Nutritional Physiological Phenomena”[Mesh]||166||15|
|“child nutrition” OR “infant nutrition”||27||4|
NOTE: Searches included documents published through the first week of December 2019.
a Values in this column have not been deduplicated across searches. Because the total number of documents screened came from database searches, a search of food-based dietary guidelines, expert input, and targeted website searches, the cumulative total in the right-hand column does not correspond to the numbers presented in Figure 2-1.
d International Guideline Library available at https://g-i-n.net/library/internationalguidelines-library/international-guidelines-library (accessed May 20, 2020).
g Given the volume of results returned, the committee adapted the search terms so the search was not too broad in scope (e.g., nutrition) and so the results were relevant to the committee’s task.
Documents and resources identified through the various searches were screened for eligibility. Screening began at the document level, to ensure the materials were relevant to the committee’s interpretation of its charge. As documents were screened, the committee recognized that some documents contained a mixture of eligible and out-of-scope recommendations, particularly in documents that were comprehensive in nature. To that end, recommendation-level criteria were applied to ensure that only relevant feeding recommendations were abstracted. A subset of committee members conducted the first round of document screenings, discussing and agreeing upon the rationale for inclusion or exclusion of each document. Document eligibility that could not be determined by the subgroup was resolved through committee discussion.
Document-Level Eligibility Criteria
Eligibility criteria used to screen the identified guideline documents are presented in Table 2-2. Screening focused on whether or not the identified document contained any recommendations on what or how to feed infants and children younger than 2 years of age; feeding recommendations encompassed human milk, infant formula, other foods and beverages, and supplements. Guideline documents that included a summary of the state of science in an attempt to make recommendations, but which found inadequate evidence to do so, were considered eligible. Given the committee’s charge of reviewing “public-facing” guidelines, eligible documents were readily accessible on the Internet. As noted previously, the committee’s search, screening, and selection focused on guideline documents relevant to healthy mother–infant dyads in the general population of high-income countries. Guideline documents specific to preterm infants were excluded owing to challenges of drawing comparisons (e.g., related to the “age” of the infant) and the special considerations related to medical management.
Recommendation-Level Eligibility Criteria
Guideline documents that screened eligible differed in span and scope. While some focused on a specific topic (e.g., vitamin D supplementation), others provided extensive guidance on a wide range of topics. To identify a collection of feeding recommendations that could be compared for consistency, the committee established recommendation-level eligibility criteria (see Table 2-3).
|Inclusion Criteria||Exclusion Criteria|
a Summaries of the state of science in an attempt to make recommendations, but which found inadequate evidence to do so, were considered eligible.
b Countries’ income levels classified using the fiscal year 2020 World Bank classification (https://datahelpdesk.worldbank.org/knowledgebase/articles/906519-world-bank-country-and-lending-groups; accessed November 8, 2019).
Challenges Encountered During Screening
Guidelines and their underlying evidence base exist in a wide range of formats. Government agencies, for instance, may publish a set of public-facing guideline documents informed by a separate scientific report. Professional organizations often publish position papers, policy statements, or practice papers or guidelines accompanied by a narrative review. Other organizations may release guideline reports with different structures and content. The format, terminology, target audience, and approach to developing guideline documents may also change over time within an organization.
Even with detailed eligibility criteria, screening the identified materials was not straightforward. As the committee’s charge was to not only com-
|Inclusion Criteria||Exclusion Criteria|
NOTE: LEAP = Learning Early About Peanut Allergy.
a Recommendations may include the primary prevention of food allergies and other common conditions (e.g., diarrhea, constipation, dental caries). However, recommendations on the treatment of a condition were excluded.
b Recommendations were excluded if they were about preterm infants; clinical treatment of a specific disease or condition; clinical management of lactation; the benefits of breastfeeding; methods for preparing and storing foods, including breast milk and formula; malnutrition or emergency situations; intake of breastfeeding mothers; or infant formula composition.
c Many agencies, organizations, and groups used the LEAP trial (Du Toit et al., 2015) to update feeding guidelines related to the primary prevention of peanut allergy. Inclusion of peanut allergy–related recommendations predating the release of the LEAP trial results would unnecessarily introduce inconsistency and those earlier recommendations were therefore excluded.
pare the consistency of guidance but also to document the type of evidence used to support each recommendation, it was imperative to find the source document of the feeding recommendations. One substantial challenge the committee faced was determining what constituted guideline documents and resources, as opposed to communication or dissemination materials. Communication materials typically include lay-friendly feeding guidance, but do not typically provide the methodological or scientific underpinning of each recommendation. Although these types of materials often provide specific feeding recommendations, the committee did not consider these resources to be eligible guideline documents. The dividing line between a guideline document and a communication product, however, is not clear-cut, and the determination is somewhat subjective. Although not a formal criterion, the committee considered whether the document provided information about the guideline development process or evidence supporting the recommendation, rather than being a simple, lay-friendly resource, in distinguishing between guidelines and communication materials.
A major resource that provides guidance on feeding infants and young children is the American Academy of Pediatrics’ Pediatric Nutrition (AAP Committee on Nutrition, 2019). This comprehensive book includes a number of sections related to what and how to feed young children. Despite its preeminence, this handbook was determined not to meet the committee’s eligibil-
ity criteria because the guidance in the book is intended to align with current AAP policy statements. Accordingly, the policy statements were considered the origin document of the recommendations. The committee acknowledges the importance of this resource to the field, but has opted to include and abstract policy and clinical practice position statements from AAP.
Even scientifically oriented documents with clear statements of guidance on what or how to feed infants and young children posed challenges. For example, in its 2019 report, Appropriate Age Range for Introduction of Complementary Feeding into an Infant’s Diet, the European Food Safety Authority Panel on Nutrition, Novel Foods and Food Allergens noted that the purpose of the document was to assess the scientific evidence, and that providing public health recommendations was considered out of scope (EFSA Panel on Nutrition, Novel Foods and Food Allergens, 2019). Nevertheless, the document provides clear statements of when to introduce complementary foods into infants’ diets and was ultimately considered eligible. In another example, the Academy of Breastfeeding Medicine published a protocol related to supplementary feedings for healthy, term breastfed newborns (Kellams et al., 2017). This guideline document provided guidance related to what and how to feed infants; however, the document was ultimately excluded because the recommendations were focused on clinical management and did not align with the committee’s interpretation of its charge.
Another challenge the committee encountered was assessing documents consistently, despite inconsistent formats. For instance, the Australian government has a suite of publications including the guideline document, the supporting literature review, public consultation on the feeding guideline document, and a summary of the recommendations (NHMRC, 2012). Taken in isolation, the guideline document does not provide the full context of the scientific review supporting each recommendation. Accordingly, when guideline documents were supported by a separate literature search or documentation of the evidence, the committee considered these publications collectively, as necessary. Some guidelines from international groups and organizations had an English guideline document or summaries, but the corresponding evidence base was not available in English (Bührer et al., 2014; Davanzo et al., 2015). These documents were ultimately excluded because the committee could not determine the type of evidence underlying the feeding recommendations. The heterogeneous formats of guidelines and associated evidence reviews posed challenges in identifying and assessing the documents in a systematic and consistent way.
Although the primary focus of the committee’s work was the feeding recommendations and supporting evidence, some of the information needed
to contextualize the feeding recommendations could be abstracted at the document level. The committee therefore abstracted information at the document level and at the recommendation level.
The following information was abstracted from each of the eligible guideline documents and resources:
- Organization(s)—The agencies, organizations, or groups that published, released, or otherwise directly participated in the development of the guideline document were recorded.
- Year—The year the guideline was published or otherwise updated was recorded.
- Target country or region, as specified in the guideline document—Unless otherwise stated, it was assumed that professional organization guidelines were for the country or region specified in the organization’s name (e.g., the target region for a guideline document from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition was Europe).
- Target audience of the document, as specified in the guideline document—Document target audiences may include, but are not limited to, health care providers (e.g., physicians, nurse practitioners, nurses, dentists, registered dietitian nutritionists, and other nutritional professionals), parents and guardians, early care and education providers, program administrators, and policy makers.
- Inclusion of conflict-of-interest statement for guideline authors—This included any statement about the guideline authors’ potential conflicts.
- Guideline development methodology—If available, the statement of methods for arriving at the recommendations was recorded as described in the document.
- Inclusion of guidance on communication and dissemination—The abstractor made note of any guidance contained within each eligible document related to changing knowledge, attitudes, and/or behaviors, and the channels by which to spread feeding guidance.
- Inclusion of research recommendations—The abstractor noted when a guideline document included a specific section or statement of research recommendations, future work, knowledge gaps, future research needs, or similar text. The content of those research recommendations, however, was not abstracted.
The committee sought to capture the following information about each eligible recommendation:
- Recommendation—The statement of recommendation was recorded verbatim. Statements of recommendation were captured, as presented in the guideline document (e.g., in paragraph form, as a stand-alone sentence, or a statement accompanied by a bulleted list).
- Type of evidence that directly maps to the recommendation—Based only on the information provided in the guideline document itself or, in select cases, in the suite of guideline-related publications, the abstractor noted whether the type of evidence used to support the recommendation could be determined and, if so, what type was used. In an attempt to standardize responses, options for type of evidence included
- Systematic review, included as part of the guideline document: This option was selected when the recommendation could be mapped to a systematic review question included in the guideline document.
- Systematic review, specifically prepared for the guideline document, but published elsewhere: This option was selected when the guideline document was part of a suite of guideline-related publications. This option was not used when a guideline document only cited a systematic review as its evidence within a narrative review of the evidence.
- Narrative review, included as part of the guideline document: This option was selected when the recommendation could be mapped to a section of the guideline document that discussed the evidence in a narrative way, and cited at least two publications (regardless of publication type).
- A single citation: This option was selected when the guideline document stated that the recommendation stemmed from one publication (e.g., a guideline document noting that the recommendation was drawn from a government website). The resource was recorded.
- Other: This option was selected when the type of evidence that mapped to the recommendation did not fall into any of the above categories (e.g., a guideline document noting that the recommendation was informed by reports from other organizations; a guideline document describing recommendations based
on a “systematic literature search” rather than a “systematic review”).
- Could not be mapped: This option was selected when the type of evidence used to support the recommendation could not be discerned, and could include instances when no evidence was presented to support a recommendation, or when the link between the evidence and recommendation was unclear.
- System used to determine strength of evidence—The specific system used to evaluate the strength of the evidence (e.g., Agency for Healthcare Research and Quality, Grading of Recommendations Assessment, Development and Evaluation) supporting the recommendation was noted.
- Strength-of-evidence rating—The verbatim word or phrase used to characterize the strength of evidence supporting the recommendation (e.g., Low, Grade B) was recorded.
During recommendation-level abstraction, abstractors noted what topic areas each recommendation addressed. The committee used these initial topic area assignments to sort and group the recommendations. Several of the recommendations encompassed multiple topic areas and were considered under each (e.g., a recommendation to “continue breastfeeding while incorporating iron-rich complementary foods” was considered under continuation of breastfeeding, complementary foods, and iron topic areas). Once the recommendations were sorted by topic area, the committee thematically grouped the recommendations and assessed the consistency of the guidance provided for each theme. Consideration was given to the specified age of the infants or young children, the duration and/or timing specified in the recommendations, and other recommendation-specific characteristics. The span of topics and consistency of recommendations are presented in Chapters 4 and 5.
As part of the document-level abstraction, each guideline document was reviewed for statements, sections, and appendixes providing guidance on who should know about the recommendations, who should communicate that information, and how that information should be communicated. Recognizing that the guidance on communication and dissemination within guideline documents themselves was relatively sparse, the committee
performed two additional exploratory scans. One scan entailed reviewing the materials identified during the document searches that screened ineligible because their primary purpose was to serve as a communication or dissemination tool. The other scan was more exploratory in nature. During the targeted website searches for guideline documents (described above), abstractors noted tools, resources, or materials that accompanied the guideline document or were hyperlinked on the exploratory pathway to the guideline document. This environmental scan was not systematic in nature, but rather was intended to find examples of existing and innovative approaches to communicating and disseminating the feeding recommendations. The committee used this information to inform its understanding of communication and dissemination strategies related to the feeding recommendations that are in use. The committee recognizes that information about communication and dissemination strategies may not be contained in the types of documents and resources reviewed, or may not be publicly available, and recognizes this as a limitation of the exploratory scans that were conducted.
The committee undertook a multipronged approach to find documents and resources from authoritative agencies, organizations, and groups that provide recommendations on what and how to feed infants and young children. Potentially relevant materials were identified through targeted website searches, food-based dietary guideline searches, expert input, and guideline database searches. A total of 156 unique documents and resources were identified and screened for eligibility. Materials that were included were relevant to healthy mother–infant dyads in high-income countries. Recommendations that were abstracted were related to human milk, infant formula, other foods and beverages, and nutrient supplements. Recommendations were sorted and thematically grouped for comparison. The landscape of guideline documents and supporting evidence were heterogeneous and required some subjectivity, which posed challenges in identifying and assessing the documents in a systematic and consistent way.
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