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PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 53 3 Principles Underlying the Nutrition Risk Criteria for WIC Eligibility The WIC program (Special Supplemental Nutrition Program for Women, Infants, and Children) uses three criteria for program eligibility: (1) categorical status as pregnant, breastfeeding, or postpartum women; infants; or children under age 5 years; (2) income less than or equal to 185 percent of the poverty level (or adjunct eligibility, see Chapter 1); and (3) evidence of nutrition risk. Eligibility on the basis of categorical status is based on the special importance of nutrition during the critical growth and development periods of pregnancy, infancy, and childhood. Eligibility on the basis of income is based on the evidence presented in Chapter 2, which shows that low-income predisposes women, infants, and children to both poor nutrition status and poor health outcomes. The WIC program's nutrition risk criteria are intended to target its limited resources to low-income individuals who either already have poor outcomes or are at the greatest risk of poor outcomes. This chapter presents the committee's underlying principles concerning the use of nutrition risk criteria for eligibility for participation in the WIC program, a description of current WIC nutrition risk criteria, a discussion of the current WIC priority system, and the framework adopted by the committee as the basis for its recommendations for the use of specific nutrition risk criteria. PRINCIPLES OF NUTRITION RISK ASSESSMENT Nutrition risk assessment uses a risk criterion. A risk criterion is defined by a risk indicator and a cutoff point. A risk indicator is any measurable characteristic or circumstance that is associated with a poor outcome or an increased likelihood of such outcomes such as poor nutrition status, poor health,
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 54 or death. Risk indicators may have causal relationships or may merely be associated with poor outcomes. For example, maternal undernutrition, short interpregnancy interval, and poverty are all risk indicators for low birth weight (a poor outcome). Maternal undernutrition (a risk indicator) has a causal linkage with low birth weight. Short interpregnancy interval (a risk indicator) does not itself cause low birth weight but may contribute to maternal nutrition depletion and may therefore contribute to the risk of low birth weight. Similarly, poverty (a risk indicator) is strongly associated with low birth weight, but the linkage is indirect. Some risk indicators (e.g., homelessness) use categorical or dichotomous cutoff points. Others, such as maternal undernutrition, have no clearly defined threshold, so several factors need to be considered in setting cutoff points, as discussed below. Purpose of Nutrition Risk Criteria in the WIC Program To target the limited resources of the WIC program, competent professional authorities assess women, infants, and children who are eligible for participation on the basis of income by using a set of nutrition risk criteria. The committee agreed that the WIC program's nutrition risk criteria should serve two major purposes: (1) to identify those at nutrition and health risk, and (2) to identify those most likely to derive specific health benefits from food, nutrition education, and/or referrals provided through the WIC program. To identify those at nutrition risk, criteria should select those who have greater need for the services of the WIC program either because they are currently more unhealthy or poorly nourished or because they are at greater risk of future ill health or malnutrition than those excluded by the screening. Moreover, nutrition risk criteria should select those most likely to benefit from the WIC program from among potential participants who are at risk of poor outcomes. In other words, the nutrition risk criteria used in the WIC program should serve both as indicators of nutrition and health risk and as indicators of nutrition and health benefit. The committee did not consider other uses of these indicators (Habicht and Pelletier, 1990), but it is important to recognize that information obtained from WIC nutrition risk assessments assists in the determination of the content of WIC interventions (food package, nutrition education, and health and social service referrals). Identifying Nutrition Risk Indicators The selection of risk indicators requires an examination of the pathways from the determinants to the undesirable outcomes, the intervention points for
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 55 WIC program activities, evidence for efficacy of the interventions, and various interactions among determinants and interventions. For example, suppose a child is not growing properly and it is found that the mother is underweight. If the cause of both the maternal thinness and the child's poor growth is hunger because of destitution, providing food or resources to acquire food will address the problem. If the cause of the mother's thinness is a lack of appetite resulting from drug abuse and the child's poor growth is due to neglect, then focusing on the mother's drug abuse may improve the child's growth. If the cause of the mother's thinness is tuberculosis that infected her child and resulted in poor child growth, then curing the child's tuberculosis is the solution to curing the poor growth. Curing the mother's tuberculosis in the first place, however, would have prevented the child's infection. Finally, if the cause of the mother's thinness is chronic malnutrition that led to an undersized newborn with poor growth potential but the mother is feeding her child adequately now, none of the WIC program's interventions will improve the child's growth. However, the low birth weight likely would have been prevented if the mother had consumed a better diet during pregnancy. Examination of causal pathways and possible interventions is a key step in identifying risk indicators that predict nutrition and health risk. In the example given above, one such indicator is maternal thinness. However, this indicator alone does not provide sufficient information to determine whether a child will benefit from a given intervention to prevent or cure poor child growth. Information from other indicators can help determine which children might experience improved growth from WIC program participation. Thus, use of more than one indicator may help to identify those with potential to benefit. Requiring that an indicator be in the pathway between a cause and a biologic impact is compatible with a preventive program, but that requirement may be too narrow. An indicator may be distantly related to the causal pathway and still be an excellent targeting indicator. In the previous example, with maternal underweight as an indicator of risk of poor child growth, one of the pathways was not causal. Maternal underweight was only a proxy for a mother at risk of neglecting her child because of drug abuse. In another example, short stature of immigrant women whose growth was stunted in their own childhood may be an excellent indicator of mothers who may benefit during pregnancy and whose children may benefit thereafter from participation in the WIC program. These immigrants are likely to be poor, often have other family members who are ill, and need to be informed to make the most of their resources in an unfamiliar country. The WIC program can be an effective intervention to prevent poor nutrition and ill health among these women and their children. Both short stature and potential to benefit from WIC program participation are independently related to recent immigration, but there is no causal link between them. Furthermore, no interventions will affect maternal stature.
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 56 A priori theoretical considerations for identifying predictors of health benefit sometimes fail. Criteria may not predict benefit because those who could most benefit from a program do not participate. Such was the case for a recently completed smoking cessation trial, in which the heavy smokers benefited less from the intervention than less heavy smokers (COMMIT Research Group, 1995). The best risk indicator for the ill effects of smoking was heavy smoking, whereas the best predictor of benefit from a smoking cessation intervention was light to moderate smoking. At other times, the biological basis may differ from the intuitive explanation. For example, Winkvist (1992) found that malnourished, thin pregnant women who weighed the least showed no weight gain from an improved diet, in contrast to a considerable weight gain in less malnourished, thin women. This is because the beneficial effects of improved diets are deflected to the fetus in the more malnourished women. Moreover, this finding implies that low prepregnancy weight may be a poor predictor of maternal weight response to food supplementation during pregnancy, but it may be a good predictor of improved birth weight. Thus, the actual responsiveness of an indicator to interventions should not always be viewed as a proxy for the indicator's ability to predict nutrition or health benefit. This example shows that it is important to consider all outcomes in selecting an indicator of benefit. In this case, improvements in the diets of severely malnourished pregnant women result in clear benefits to the fetus. Setting Cutoff Points for Nutrition Risk Indicators Once a risk indicator is chosen as a predictor of nutrition and health benefit, a cutoff point for the indicator is set at the level below (or above, depending upon the indicator) which individuals are eligible for participation in the WIC program. In general, more stringent cutoff points can be chosen to increase the potential of risk indicators to select those individuals who will benefit. This increase occurs for two reasons. The first relates to the degree of risk. In general, the greater the risk predicted by an indicator, the greater the expected nutrition and health benefit for the individual chosen (see above for some exceptions). As an extreme example, moderate thinness, reflecting moderate malnutrition, may predict that the woman will become more physically active if she becomes better nourished, whereas severe thinness, reflecting severe malnutrition, may predict that she will avoid death if she becomes better nourished. Preventing death is a greater benefit than increasing physical activity. Thus, the more stringent a cutoff pointâthat is, the further a cutoff point is from the average for a healthy personâ the greater the likely benefit to the individual.
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 57 The second reason for increased potential to benefit with more stringent cutoffs points relates to yield. The term yield is used to identify the percentage who will actually experience nutrition and health benefit of those individuals selected by a risk indicator and its cutoff point.1 By moving the cutoff point toward levels that predict worse conditions, the percentage of those chosen who will benefit will be greater. As the cutoff point is made progressively more stringent, it will reach a point such that all those chosen will benefitâa perfect yield of 100 percent. Increasing the yield of nutrition risk criteria helps target scarce resources. A perfect yield occurs at any cutoff point at which all of those selected for participation in the WIC program can benefit and nobody who cannot benefit is selected. A perfect yield, however, means that there is a high likelihood that many who could benefit are not selected. Identification of all who could benefit is called perfect sensitivity of the risk assessment. Ideally, the value of the cutoff point would be set so that as many as possible who could benefit would be served (high sensitivity) and most of those served would experience nutrition and health benefit (high yield). In general, there is a trade-off between yield and sensitivity. For example, consider the risk criterion for a child's poor growth, as defined by height-for-age less than the 5th percentile according to standard growth references.2 Low height-for-age, also called stunting, is generally considered to reflect long-term nutrition status. Setting the cutoff point at the 5th percentile has implications for both sensitivity and yield. Only children with height-for-age at or less than the 5th percentile would be selected. Sensitivity is imperfect (< 100 percent) if some children who are taller than the cutoff point are still smaller than their genetic potential. These stunted children would not be selected by the 5th percentile cutoff point, yet they could benefit from better nutrition and, consequently, participation in the WIC program. The yield using this cutoff point may also be quite low. Estimates of the prevalence of height-for-age less than the 5th percentile among low-income children in the United States range from 6 to 7 percent (Yip et al., 1992). Assuming 1 A similar concept is called the positive predictive value (Last, 1988) when it is applied to an indicator predicting the risk of death or the presence of disease. However, because of the confusion that arises when the term positive predictive value is applied to predict a benefit instead of a risk, the committee concluded that the concept of yield is easier to grasp in the sense that moving the cutoff point toward a higher level of prediction of benefits yields a greater percentage of those who can benefit. For simplicity, in this report, the committee calls the positive predictive value of risk the yield of risk and differentiates between the yield of risk and the yield of benefit. 2 All reference standards are imprecise, and those used in this example have been well enough studied so that the imprecisions are recognized (e.g., Gorstein et al., 1994).
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 58 that 5 percent of healthy, well-nourished children have height-for-age less than the 5th percentile, then only 1 to 2 percent of the low-income children are actually stunted, resulting in a yield of risk of only 17 percent (1/6) to 29 percent (2/7). If the cutoff point is increased to the 10th percentile, the sensitivity of the higher cutoff point is higher: additional children who are stunted will be selected by the more generous cutoff point. However, the yield of the risk criterion will decline, since fewer of the additional children selected are stunted and therefore will not experience improved growth from participation in the WIC program. In contrast, if the cutoff point is lowered to the 2nd percentile, the yield will improve (more of those selected could benefit from improved nutrition), but the sensitivity will decline (a larger number of children who could benefit are above the cutoff point and will not be selected). Thus, the yield of a risk criterion increases with the prevalence of the risk in the population. For instance, using the above example of the cutoff point at the 5th percentile of height-for-age, if 30 of 100 children were below the cutoff point, the number of children with stunted growth would be 25 (30 â 5), and the yield will be 83 percent (25/30). It is therefore important to monitor the prevalence of changing risk conditions, including medical conditions and social conditions such as homelessness, and to make changes in the WIC program nutrition risk criteria as appropriate. Possible changes in response to the changing prevalence of risks include adding new risk indicators, for example, homelessness, or changing cutoff points, for example, moving the cutoff point for height-for-age below the 5th percentile as the prevalence of poor growth declines. The WIC program typically uses several risk criteria in addition to the income screen to determine eligibility for participation in the program. For instance, adding hemoglobin assessments to anthropometric assessments will identify anemic children who are not identified by slow growth. If this process identifies more individuals who can benefit without increasing the percentage who cannot, the yield will not decrease, and such a combination of risk criteria also improves sensitivity. It is usually impossible to achieve both perfect sensitivity (identification of all who could benefit) and maximum yield (of those selected, all could benefit). The question, then, is how to choose the best cutoff point. When resources are sufficient to serve everybody selected, the cutoff point with perfect sensitivity is the logical cutoff point. A less stringent cutoff point would not be scientifically justified because it would decrease the yield without increasing the sensitivity. However, any cutoff point with perfect sensitivity includes a high percentage of individuals who will not benefit. If resources are limited, however, cutoff points should be set with less than perfect sensitivity to increase yieldârecognizing that as the cutoff points become more restrictive, some individuals who could derive nutrition and health benefits from participation in the WIC program will not be served. In general,
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 59 cutoff points should be chosen so that the highest percentage of those selected are at risk and can benefit from WIC program services. This most efficient cutoff point will nevertheless include a number of participants who will not benefit (false positives) and will exclude some who can benefit (false negatives). The numbers of false positives and false negatives can be reduced by using improved criteria or combinations of criteria, but they can never be reduced to zero. Excessive lowering of cutoff points to reduce false positives would be counterproductive, since it would prevent access to services by many who truly need them. It must be recognized that unmet needs of prevention or cure that result from imperfect sensitivity may have costs that would outweigh the costs of providing services to the false positives if sensitivity were improved. This would be a strong argument for increasing resources to the WIC program to increase overall coverage. However, such considerations are beyond the purview of this report. In evaluating the use of nutrition risk criteria in the WIC program, it is important to note that the yield of a risk criterion refers to the yield of benefit and is actually the product of the yield of risk and the efficacy of the WIC program for individuals with that risk: That is, the yield of risk is the percentage of those truly at-risk who are identified at risk by the risk criterion. These truly at risk people are individuals who would be sure to have a bad outcome without intervention. The proportion of those at risk who will benefit from the WIC program is the efficacy of the WIC program for individuals with that risk. (See Appendix D for more detailed information.) Nutrition risk criteria can vary considerably in these two components. In the United States, some anthropometric criteria (e.g., low height-for-age) have poor yields in terms of identifying those at risk but good yields in terms of benefiting those truly at risk. Other nutrition risk criteria (e.g., homelessness and overweight) have good yields in terms of identifying those with the risk but poor or unknown yields in terms of benefiting those at risk. Overall yield of benefit will be very low if the yield of risk and the efficacy are both low. It might appear from the above discussion that the criteria with the highest risk yield will also have the highest benefit yield for the same outcome, intervention, and sensitivity. This is not necessarily the case. Recent research involving length and weight at age 3 months shows that length is the better predictor of deficits in adult stature that are due to childhood malnutrition. However, weight is the better predictor of response of stature to an improved diet (Ruel et al., in press). This finding means that the two different indicators
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 60 have different yields for deficits in stature that are preventable by better diet. The intervention had better efficacy for those deficits in stature that were predicted by weight than for those predicted by length. WIC NUTRITION RISK CRITERIA According to federal regulation, each participant in the WIC program must be determined to be at nutrition risk on the basis of a medical and/or nutrition assessment by a competent professional authority. At a minimum, federal regulations require that the following nutrition and health data be collected on each potential participant: height or length, weight, and a hematologic test for anemia (hematocrit, hemoglobin, or free erythrocyte protoporphyrin concentration). Hematologic tests are not required for infants under 6 months of age. For pregnant women, this minimum set of nutrition and health information must be collected during pregnancy and, if the woman was given presumptive eligibility, within 60 days from prior certification. Collection of data on women certified as postpartum or breastfeeding must be collected after they give birth (7 CFR, Subpart C, Section 246.7(d)(1)). At the state or local agency's discretion, the blood test is not required for children who were determined to be within the normal range at their last program certification, but it must be performed every 12 months. WIC program regulations define nutrition risk as shown in Table 3-1. PRIORITY SYSTEM OF THE WIC PROGRAM Because the WIC program is not an entitlement program, participation is limited by funding levels, which have never been adequate to serve all eligible applicants. Once a local agency is serving its maximum caseload, federal regulations require that a waiting list of eligible applicants be maintained. As program openings become available, they are to be filled from the waiting list according to a seven-point priority system. Federal regulations specify a seven-point priority system, in which all priorities are related to nutrition risk (Table 3-2). Priorities I through VI are used by all states. State WIC agencies may, at their discretion, expand the priority system to include Priority VII. Individuals who qualify for participation in the WIC program under Priority I are served first, then those in Priority II, and then in each subsequent priority, until program resources are exhausted. A state WIC agency may also assign subpriorities within each of the seven priority levels. In general, priority is given to anthropometric, hematologic, and clinical evidence
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 61 of medically based nutrition risks over dietary-based nutrition risks; to pregnant and breastfeeding women and all infants over children; and to children over postpartum women3 (7 CFR Subpart C, Section 246.7 (d)(4)). TABLE 3-1 Nutrition Risk Criteria Defined by WIC Program Regulations Conditions Detectable by Biochemical or Anthropometric Measurements: ⢠anemia ⢠underweight ⢠overweight ⢠abnormal patterns of weight gain in a pregnant woman ⢠low birth weight in an infant ⢠stunting in an infant or child Other Documented Medical Conditions: ⢠clinical signs of nutrition deficiencies ⢠metabolic disorders ⢠preeclampsia in a pregnant woman ⢠failure to thrive in an infant ⢠chronic infections in any person ⢠alcohol or drug abuse or mental retardation in women ⢠lead poisoning ⢠history of high-risk pregnancies or factors associated with high risk-pregnancies (such as smoking; conception before 16 months postpartum; history of low birth weight; premature births, or neonatal loss; adolescent pregnancy; or current multiple pregnancy) ⢠congenital malformations in infants or children ⢠infants born to women with alcohol or drug abuse histories or mental retardation Dietary Nutrition Risk Criteria: ⢠inadequate dietary patterns assessed by a 24-hour dietary recall, dietary history, or food frequency checklist Predisposing Nutrition Risk Criteria: ⢠homelessness or migrancy SOURCE: 7 CRF Subpart C, Section 246.7 (e)(2). The use of a priority system of risk criteria can help to achieve the highest yield in the face of limited program resources. For the system to be most effective, nutrition risk criteria that have high yield would be given priority in assigning eligibility. The WIC priority system reflects a preference for 3 Furthermore, local agencies whose caseloads force them to serve only individuals given the top priorities frequently serve children according to age. Some clinics serve children who are 1 to 2 years of age but not children 3 years of age and older, or some agencies serve participants up to 12 months of age and then serve them only one certification period beyond their first birthday, up to 18 months of age.
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 62 biologically measurable indicators of risk that respond to the WIC program intervention and that are in the causal pathway from the determinant to the undesirable outcome. TABLE 3-2 The WIC Priority System Priority I Pregnant and breastfeeding women and infants at nutrition risk as demonstrated by anthropometric or hematologic measurements or by other documented nutrition-related medical condition.a II Infants up to 6 months of age whose mothers participated in the WIC program during pregnancy or who would have been eligible to participate under Priority I.a III Children at nutrition risk, as demonstrated by anthropometric or hematologic measurements or other documented medical condition. At the state's option, this priority can also include high-risk postpartum women. IV Pregnant and breastfeeding women and infants at nutrition risk as demonstrated by inadequate dietary pattern. At the state's option, this priority can also include high-risk postpartum women or pregnant or breastfeeding women and infants who are at nutrition risk solely because of homelessness or migrancy. V Children at nutrition risk because of inadequate dietary pattern. At the state's option, this priority can also include high-risk postpartum women or children who are at nutrition risk solely because of homelessness or migrancy. VI Postpartum women, not breastfeeding, at nutrition risk on the basis of either medical or dietary criteria, unless they are assigned to higher priorities at the state's discretion. This priority, at the state's option, may also include postpartum women who are at nutrition risk solely because of homelessness or migrancy. VII Individuals certified for WIC program participation solely because of homelessness or migrancy and, at the state agency option, previously certified participants whose nutrition status is likely to regress without continued provision of supplemental foods. a A breastfeeding mother and her infant shall be placed in the highest priority level for which either is qualified. SOURCE: 7 CRF Subpart C, Section 246.7(d)(4), and Federal Register, April 19, 1995, 60(75):19, 487-419, 491. Several issues need to be considered in interpreting the nutrition risks used in the WIC priority system. First, most biologically measurable indicators (e.g., low hemoglobin concentration) that respond to WIC program benefits (e.g., iron-fortified foods) are evidence of pathology (e.g., anemia) and are therefore indicators for a curative and not a preventive program. The high priority that the WIC program gives these indicators is in concert with the policy that curing the present ill is generally to be given a higher priority than preventing a future ill. However, the WIC program also is supposed to be preventive so that it is not
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 63 faced with curing problems that it could have prevented. If a high percentage of the WIC program resources is taken up in curing problems, the WIC program will be unable to fulfill its preventive role. Second, there may be different degrees of risk within a priority category. Many states recognize this and set subpriority levels within any given priority category. For example, hemoglobin or hematocrit measurements may serve to assign subpriority risk levels that differentiate among individuals with varying risks of anemia. The WIC priority system generally does not operate such that a high subpriority condition in priority level VI, for example, would be served in preference to a low subpriority condition in priority level V. A final issue to consider in the context of the WIC priority system is the dual objective of a preventive and curative program. Some state WIC agencies have set nutrition risk criteria with the intent of selecting both those who have the condition and those who might develop the condition if not given WIC program benefits. Criteria for anemia fall in this category. However, generous cutoff points do not necessarily achieve this goal. The committee affirms the importance of primary prevention and suitable methods to identify those at risk of developing health and nutrition problems. However, it believes that more work is needed to find the best methods for achieving this. When resources are limited and not all individuals eligible for participation can be served, it is important that the criteria in the highest priority levels have the highest overall yields possible. That is, the overall yield in Priority I should be higher than the overall yield in Priority II, and so on. It is likely that some of the predisposing nutrition risk indicators at current low priority levelsâe.g., homelessnessâmay have higher overall yields than some medical risk indicators in Priority Iâfor example, asymptomatic bacteriuria as a renal medical risk for pregnant woman. With the current priority system, an overweight child who may not actually benefit would be served in preference to a homeless child who would be more likely to benefit from participation in the WIC program. SUMMARY AND IMPLICATIONS In summary, the best criteria for targeting WIC program benefits are those that most closely predict a potential nutrition and health benefit from these interventions. Theoretical considerations in choosing indicators, such as how close they are in the causal pathway to the outcome to be prevented, are less important than how well the indicator actually targets those who will benefit from the intervention. However, very few indicators used in the WIC program or elsewhere have been examined for this characteristic. In the meantime, the decision of which criteria to use must be based on the degree to which the criterion is both an indicator of risk and, theoretically, also an indicator of
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 64 potential benefit. The risk criteriaâthat is, the risk indicators and their cutoff pointsâshould be chosen and prioritized such that a high percentage of those truly at risk will be selected and a high percentage of those selected can benefit. In the discussion in the subsequent chapters of this report, the committee examines the association between the risk indicators and nutrition and health outcomes in situations similar to those encountered by WIC program participants. Then, the committee examines why, in theory, these risk indicators might be indicators of potential benefit. In addition, empirical evidence of the ability to predict a benefit, if such evidence exists, is presented. In many cases, the discussion focuses on evidence of efficacy of the WIC program only since no information about yield of benefit is available. Based on this framework, the committee makes recommendations for each of the nutrition risk criteria reviewed. The following decision process underlies these recommendations: ⢠For nutrition risk criteria for which there is good evidence of both nutrition and health risk and benefit from the WIC program, the committee recommends use of these criteria by all state WIC programs. ⢠For nutrition risk criteria for which the risk indicator is a predictor of both nutrition and health risk and benefit from the WIC program but for which cutoffs have been set so that many individuals selected are not truly at risk, the committee recommends using the risk indicator with more stringent cutoff values. ⢠For risk criteria for which there is strong evidence of nutrition and health risk but uncertain evidence of benefit, the committee recommends using the nutrition risk criteria and conducting further research on the benefit from the WIC program. ⢠For risk criteria for which there is good evidence of nutrition and health risk and benefit from the WIC program but poor ability to identify those with the condition, the committee recommends that action be taken to develop better assessment tools. Pending this assessment, the committee recommends using the best available methods to identify the condition, using scientifically justifiable cutoff values. ⢠For risk criteria for which there is strong evidence of nutrition and health risk but no direct or indirect evidence of benefit, either theoretical or empirical, the committee recommends discontinuing use of these criteria. ⢠For risk indicators with weak evidence of risk or benefit, the committee recommends discontinuing use of these criteria. The WIC program is a broad-based and comprehensive food and nutrition program with three main components: (1) supplemental foods, (2) nutrition education, and (3) referrals to health care and social service providers. Thus, evidence of benefit from the WIC program, either theoretical or empirical, could be from any of the three program components. In making its recommendations
PRINCIPLES UNDERLYING THE NUTRITION RISK CRITERIA FOR WIC ELIGIBILITY 65 for each nutrition risk criterion, however, the committee decided that evidence of benefit from the WIC program should reflect the ability of an individual with that risk to benefit from the WIC food package or, in some cases, from nutrition education. Benefit from only the referral services of the WIC program was not considered sufficient to justify the use of a nutrition risk criterion. Three main reasons for this decision follow: (1) the provision of supplemental foods and nutrition education account for nearly all the WIC program costs; (2) it is difficult to justify the provision of a monthly food package worth approximately $30 per WIC participant unless there is evidence that the individual can benefit from the food package or the nutrition education that accompanies the provision of food; and (3) the WIC program is designed to be only an adjunct to good health care and is not itself a health program. REFERENCES COMMIT Research Group. 1995. Community Intervention Trial for Smoking Cessation (COMMIT). I. Cohort results from a four-year community intervention. Am. J. Public Health 85:183-192. Gorstein, J., K. Sullivan, R. Yip, M. de Onis, F. Trowbridge, P. Fajans, and G. Clugston. 1994. Issues in the assessment of nutritional status using anthropometry. Bull World Health Organ. 72:273-283. Habicht, J-P., and D.L. Pelletier. 1990. The importance or context in choosing nutritional indicators. J. Nutr. 120:1519-1524. Last, J.M. 1988. A Dictionary of Epidemiology. London: Oxford University Press . Ruel, M.T., J-P. Habicht, K. Rasmussen, and R. Martorell. In press. Screening for interventions: The risk or benefit approach? Am. J. Clin. Nutr. Winkvist, A. 1992. Maternal Depletion Among Pakistani and Guatemalan Women. Ph.D. Dissertation, Cornell University, Ithaca, N.Y.. Yip, R., I. Parvanta, K. Scanlon, E.W. Borland, C.M. Russell, and F.L. Trowbridge. 1992. Pediatric nutrition surveillance systemâUnited States, 1980-1991. Morbid. Mortal. Weekly Rep. 41 (SS-7):1-24.
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