Dietary Risk Assessment in the WIC Program (2002)

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides supplemental foods, nutrition education, and health referral services to low-income pregnant or postpartum women, infants, and young children. As specified in the Child Nutrition Act of 1966, the program is intended to “serve as an adjunct to good health care, during critical times of growth and development; to prevent the occurrence of health problems, including drug abuse; and improve the health status of these persons” (Child Nutrition Act of 1966 [As Amended Through Public Law 106-224, June 20, 2000]). The program is based on the premise that low income predisposes women, infants, and children to poor nutritional status and adverse health outcomes. Part of establishing program eligibility (see later section, “Nutrition Risk Criteria”) requires the determination of nutritional risk. By identifying individuals with specific nutrition-related risks and providing food and services targeted at reducing these risks, the program seeks to improve overall health and birth outcomes.

Dietary risk is only one of five categories of nutrition risk, but it is the basis for WIC eligibility for a large percentage of applicants. However, methods for identifying individuals who are at dietary risk have posed a long-standing problem for this program. This report seeks to evaluate the use of various dietary assessment tools and to make recommendations for their use in identifying individuals who are at dietary risk. It focuses on two types of dietary risk: failure to meet Dietary Guidelines and inadequate diet.

Established in 1972 through an amendment to the Child Nutrition Act of 1966, the WIC program has grown substantially and in 2001 served about 7.3 million participants each month (USDA, 2001d). The program is administered by the Food and Nutrition Service (FNS) of the U.S. Department of Agriculture (USDA). In fiscal year 2000, FNS provided cash grants totaling $4.1 billion to 88 state agencies (USDA, 2000a). State agencies include all 50 states, the 5 U.S. Territories (American Samoa, the District of Columbia, Guam, Puerto Rico, and the American Virgin Islands), and 33 Indian Tribal Organizations. Together, state agencies administer the WIC program through approximately 2,000 local WIC agencies and 10,000 service sites (USDA, 2001b).

Unlike the Food Stamp or Medicaid Programs, WIC is not an entitlement program. Rather, it is a grant program for which funding limits are set annually by Congress. Like some other federal programs, WIC requires applicants to meet income and categorical criteria (in this case, pregnant, postpartum, or lactating women and children under the age of 5 years). WIC is unique, however, in that applicants also must be found to have a nutrition risk to be eligible for participation. Nutrition risk categories include anthropometric, biochemical, medical, and dietary risks, as well as some predisposing conditions (see Box 1-1

for a summary of WIC eligibility requirements). The categorical and nutrition risk categories provide a means to prioritize individuals based on health risk and the potential to benefit from the program. Such prioritization is necessary when funding is not sufficient to provide benefits to all who meet the categorical and income eligibility requirements. In recent years, funding has been sufficient to eliminate essentially all waiting lists. However, if prioritization were necessary because of limited funding, services would be offered according to a seven-level priority system (Box 1-2).

Nutritional risk is composed of five broad categories: anthropometric, biochemical, clinical/health/medical, dietary, or other. Each of these categories contains

subgroups of indicators and specific criteria. A criterion is defined as a nutrition risk indicator and its cut-off point. For example, elevated blood lead level is a biochemical indicator. The approved criterion is a blood lead value greater than or equal to 10 µg/dL. Box 1-3 lists the five broad categories of nutrition risk criteria and their most common subgroups. A complete list of currently approved nutrition risk criteria can be found in Appendix A.

A history of dietary risk assessment in the WIC program provides a useful background for the current study (see Box 1-4). Until recently, state agencies had been permitted to develop their own nutrition risk criteria using broad federal guidelines. As expected, this flexibility resulted in wide variation for indicators and cut-offs. In 1989, prompted by concern over the variation in eligibility determination, Congress mandated a review of the nutrition risk criteria and priority system. In 1993, FNS contracted with the Food and Nutrition Board (FNB) of the Institute of Medicine (IOM), National Academies, to conduct a comprehensive scientific assessment of the nutrition risk criteria for use as eligibility criteria in the WIC program.

In 1996, IOM released its recommendations through the report WIC Nutrition Risk Criteria: A Scientific Assessment (IOM, 1996). With regard to dietary risk, the report reviewed three major categories: inappropriate dietary patterns, inadequate diet, and food insecurity. Documenting clear health and nutrition risks associated with selected inappropriate dietary patterns, the report concluded that individuals at risk for these patterns have a high potential to benefit from participation in the WIC program. It recommended the development of valid assessment tools for the purpose of identifying commonly consumed foods, thereby providing a starting point for nutrition education. With regard to inadequate diet as an eligibility criterion, the committee recommended discontinuing its use as a criterion for eligibility. With regard to food insecurity, the committee concluded that those at risk would likely benefit from participation in the WIC program. However, while the committee recommended that food insecurity be included as a risk criterion, they found insufficient scientific evidence on which to select a cut-off point to identify those most likely to benefit.

USDA has made progress in the development of tools to assess food security since the 1996 IOM report’s recommendation to include food insecurity as a criterion. In particular, USDA has developed an 18-item assessment form and supported the development of a 6-item short form by Blumberg and colleagues for use in measuring household food security (Blumberg et al., 1999). Some WIC clinics use similar instruments or include food security questions in their client interviews. However, there currently are no available tools that accurately assess food insecurity at the individual level.

Food insecurity is associated with a higher risk of an inadequate diet and is strongly related to household income, but individuals living in food secure households can still have inadequate diets. The committee recognizes the

significance of food insecurity as a potential contributing factor to dietary risk and nutritional risk, but it did not specifically address the question of assessing food insecurity within the WIC population for several reasons: (1) the available

measurement tool is an income-driven assessment at the household level rather than a dietary risk assessment at the individual level; (2) while food insecurity is considered to be one of several factors that could potentially put an individual at dietary risk, it is not an accurate indicator of all those at dietary risk; and (3) it falls outside the specific definitions of failure to meet Dietary Guidelines and inadequate diet.

Following the release of the 1996 IOM report, FNS and the National Association of WIC Directors (NAWD) formed a joint working group, the Risk Identification and Selection Collaborative (RISC), to address recommendations of the IOM report and to develop standardized and scientifically sound nutrition risk criteria. The intent was to achieve greater consistency among state and local WIC agencies. Through multiple subcommittees, the RISC working group developed three lists of nutrition risk criteria: criteria that are allowed, criteria that are not allowed, and criteria that are in need of future review. FNS released a final policy memorandum in June 1998 that described over 100 allowable nutrition risk criteria. These criteria were implemented as of April 1, 1999 (FNS, 1998), and continue to be updated regularly. The current list of allowable criteria can be found in Appendix A. In order to allow states some flexibility to meet local priorities and needs, state agencies may establish more restrictive cut-off points as long as definitions of the indicators are not changed. For example, a state may choose to use “greater than the ninety-fifth percentile of weight for height” rather than the cut off of the ninetieth percentile cited in the allowable risk criterion (FNS, 1998).

The focus of this report falls within one category of nutrition risk: dietary risk. More specifically, it focuses on methods or tools used to assess risk of an individual according to two specific dietary risk criteria: failure to meet Dietary Guidelines and inadequate diet.

Data from state agencies make it clear that dietary risk is the most commonly reported nutrition risk in WIC applicants—no other single category comes close. In 1998, 49 percent of WIC applicants (47 percent of women, 13 percent of infants, and 68 percent of children ages 1 to 5 years) were reported to have met dietary risk criteria (Bartlett et al., 2000). Because of differences in reporting practices, these percentages are likely to be underestimated. The second most commonly reported subcategory of nutrition risk was “high weight for height,” at 17 percent of participants. Again, because of differences in reporting practices, this percentage is likely to be underestimated. Only two-thirds of state agencies report all documented risk criteria for participants; the remaining third follow some other type of reporting procedure (e.g., they report only the three or four most serious nutrition risks).

The percentage of children served by WIC found to be at dietary risk has increased steadily over the years. In 1992, 52 percent of WIC-served children were reported to be at dietary risk compared to 68 percent in 1998 (Bartlett et al., 2000). A portion of this increase reflects the growth of WIC—increased funding allowed WIC to serve more children in priority level 5 (Box 1-2).

As defined by the Code of Federal Regulations, dietary risk refers to dietary deficiencies that impair or endanger health, such as inadequate dietary patterns assessed by a 24-hour dietary recall, dietary history, or food frequency checklist (7CFR Subpart C, Section 246.7(e)(2)(iii)). WIC eligibility based on this category is intended to prevent the occurrence of malnutrition or other overt problems of dietary origin due to suboptimal dietary patterns, and result in improved health outcomes for the pregnant woman, mother, fetus, infant, and young child.

Most states generally define dietary risk as failure to consume a minimum number of servings from one or more food groups represented in the Food Guide Pyramid (see Chapter 2). The 1996 IOM report defined dietary inadequacy as food or nutrient intake insufficient to meet a specified percentage of the Recommended Dietary Allowances (RDAs) (NRC, 1989) for one or more nutrients (IOM, 1996). Determination of inadequate diet has historically involved estimating nutrient intakes using some method of dietary recall or food frequency questionnaire and then comparing the reported intake with a specified percentage of the RDAs for the individual (often between 70 and 100 percent of the RDA) (IOM, 1996).

WIC Policy Memorandum 98-9 contains 18 specific dietary risk criteria (Box 1-5). Although state agencies may only use criteria on the allowable list, the agencies are given the prerogative to exclude an allowable criteria if so desired. Although failure to meet Dietary Guidelines (401) and inadequate diet (422) are included among the 18 allowable dietary risk criteria, they are the only two for which definitions and cut-off points have not been set officially. State agencies continue to be accorded discretion within broad federal guidelines to define these two criteria (the indicators and cut-off points to be used) and choose tools to assess them.

Early in the study, the committee recognized confusion with the terms used to describe dietary risk—specifically inadequate and inappropriate diets or patterns. For this reason, the committee adopted working definitions for use in this report. Dietary risk is a broad term and refers to any inappropriate dietary pattern. Inappropriate dietary pattern includes both inadequate and excessive intakes of food, nutrients, or other dietary substances over time that are unsuit- able for optimal health, growth, or development according to the Dietary Guidelines for Americans (Dietary Guidelines) (USDA/HHS, 2000). It also includes other

undesirable patterns or practices (e.g., early introduction of solid foods to infants, feeding cow’s milk before age 1 year).

• Inadequate dietary intake is a subgroup of inappropriate dietary patterns and refers to dietary intake that is either low in nutrients (inadequate nutrient intake) or low in food group servings as specified in the Dietary Guidelines (see Chapter 4).

• Excessive dietary intake is a subgroup of inappropriate dietary patterns and refers to overconsumption of energy, nutrients, or food group servings as specified in the Dietary Guidelines).

The committee viewed these descriptors as overlapping rather than as discreet entities. For example, dietary intake that meets the definition of inadequate diet would also meet the definition of inappropriate diet or failure to meet

Dietary Guidelines. However, a diet that meets the definition for failure to meet Dietary Guidelines would not necessarily meet the definition for inadequate diet.

The 1996 IOM report documented evidence to support the use of Dietary patterns that fail to meet the Dietary Guidelines as an indicator of both health risk and benefit in the WIC program. Consequently, it recommended the use of the 1995 Dietary Guidelines (USDA/HHS, 1995) in setting dietary risk criteria for women and for children over 2 years of age. However, the report did not provide guidance about how to do so. Instead, it noted that “any cut-off points would be arbitrary,” and recommended “research to develop and test practical dietary assessment instruments that would identify those who fail to meet Dietary Guidelines” (IOM, 1996).

Since the release of the IOM report’s recommendation in 1996, the Dietary Guidelines have been revised. Like earlier versions, the 2000 Dietary Guidelines (USDA/HHS, 2000) represent the basis for federal policy and are used to guide nutrition information, education, and interventions for federal, state, and local agencies. The guidelines, which are updated every 5 years, are based on current knowledge about how dietary intake may reduce the risk of major chronic diseases and how a healthful diet may promote health. They go well beyond the avoidance of dietary deficiencies; rather, they emphasize overall dietary patterns that can help to achieve favorable long-term health outcomes.

Although structured differently than the 1995 Dietary Guidelines, the 2000 Dietary Guidelines are similar in content, but include two new guidelines regarding food safety and physical activity (Box 1-6). Embedded in the guidelines is the Food Guide Pyramid—one of the major tools used for consumer nutrition education in the United States. The pyramid incorporates many of the Dietary Guidelines (see Chapter 4) and gives concrete recommendations that promote moderation, balance, and variety in food intake. Released in 1992, the pyramid reflects the 1989 Recommended Dietary Allowances for nutrients (NRC, 1989; USDA, 1992).

For the aforementioned reasons, FNS contracted with FNB to appoint a committee of experts to review the scientific basis for methods currently employed in the assessment of individuals for eligibility to the WIC program based on dietary risk. The committee’s task was to evaluate the use of various dietary

assessment tools and to make recommendations for the assessment of inadequate or inappropriate dietary patterns. The focus of the evaluation was to be on tools that could accurately identify dietary risk of individuals and thus eligibility for participation in WIC. More specifically, the committee was charged with the following tasks:

• proposal of a framework for assessing dietary risk among WIC program applicants, focusing on failure to meet Dietary Guidelines as a risk criterion;

• identification and prioritization of areas of greatest concern when the Dietary Guidelines are incorporated into the WIC program;

• examination of the use of food-based and behavior-based approaches in assessing failure to meet Dietary Guidelines requirements specifically in the WIC setting;

• identification of specific cut-off points for any approaches identified as useful for establishing eligibility based on dietary risk; and

• identification of needed research and tools necessary for the implementation of any approaches identified as having the greatest potential for identifying those at nutrition risk.

Given that the Dietary Guidelines are not meant to be applied to children under the age of 2 years, the committee was requested to evaluate the above tasks only for women and for children over the age of 2 years.

In accordance with the IOM committee process, an expert committee was appointed with the above charge in mind. It was composed of nine individuals with a variety of professional degrees and with expertise in the areas of dietary assessment methodology, eating and behavior, dietetics, epidemiology, nutrition, obstetrics, public health, and pediatrics. A list of committee members, including a description of their backgrounds and expertise, is included in Appendix C.

The committee met five times over a 13-month period to consider its scope of work; review relevant evidence; and develop its findings, conclusions, and recommendations. To assist the committee in its deliberations, one meeting included a public workshop on Dietary Risk Assessment in the WIC Program on June 1, 2000, in Washington, D.C. Eight experts on various aspects of dietary assessment, four state WIC representatives whose states use different assessment methods and serve demographically diverse population groups, and two public policy experts gave formal presentations. During the workshop, interested individuals and organizations were invited to present both oral and written testimony to the committee. Overall, the workshop served to aid in the clarification of many important issues related to the committee’s charge. The workshop agenda can be found in Appendix B.

Initially, the committee conducted a comprehensive search of the literature regarding dietary assessment methodology. All retrieved citations were reviewed to determine whether the citation was relevant to this report and, if relevant, whether to obtain the full paper. Throughout the study period, additional references were identified and obtained.

In December 1999, on behalf of IOM, NAWD regional directors requested all state agencies to send any currently used dietary assessment tools for the Committee on Dietary Risk Assessment’s review. Characteristics of the tools submitted are reviewed in chapter 2. Committee members also visited local WIC clinics in their own geographic areas to familiarize themselves with current WIC clinic conditions and practices.

In September 2000, FNB/IOM released an interim report, Framework for Dietary Risk Assessment in the WIC Program. That report contained the framework for evaluating dietary risk assessment methods, summaries of presentations from the workshop on Dietary Risk Assessment, and the compilation of relevant citations from the literature.

The report is organized into three sections:

• Chapters 1–3 set the stage for the report—giving an overview of the committee’s statement of task and issues at hand, including a brief introduction to the WIC program and nutrition risk criteria, dietary risk and potential program

benefits for eligible individuals, and the relationship of the Dietary Guidelines to the WIC population.

• Chapters 4–8 discuss the committee’s framework for evaluating possible methods to assess dietary risk among WIC program applicants and review data bearing on the ability of food-based, physical activity-based, and behavioral-based assessment tools to classify individuals correctly on the basis of dietary risk.

• Chapter 9 presents a summary of the committee’s findings and recommendations regarding the use of dietary, physical activity, and behavioral assessment tools in the WIC program.