Validation of measures of food insecurity and hunger.
The most recent survey effort to determine the extent of food insecurity and hunger in the United States, the Food Security Supplement, included a series of questions to assess this complex phenomenon. The primary measure developed from this Food Security Supplement was based on measurement concepts, methods and items from two previously developed measures. This paper presents the evidence available that questionnaire-based measures, in particular the national food security measure, provide valid measurement of food insecurity and hunger for population and individual uses. The paper discusses basic ideas about measurement and criteria for establishing validity of measures and then uses these criteria to structure an examination of the research results available to establish the validity of food security measures. The results show that the construction of the national food security measure is well grounded in our understanding of food insecurity and hunger, its performance is consistent with that understanding, it is precise within usual performance standards, dependable, accurate at both group and individual levels within reasonable performance standards, and its accuracy is attributable to the well-grounded understanding. These results provide strong evidence that the Food Security Supplement provides valid measurement of food insecurity and hunger for population and individual uses. Further validation research is required for subgroups of the population, not yet studied for validation purposes, to establish validity for monitoring population changes in prevalence and to develop and validate robust and contextually sensitive measures in a variety of countries that reflect how people experience and think about food insecurity and hunger. (+info)
Measuring food insecurity and hunger in the United States: development of a national benchmark measure and prevalence estimates.
Since 1992, the U.S. Department of Agriculture Food and Nutrition Service (FNS) has led a collaborative effort to develop a comprehensive benchmark measure of the severity and prevalence of food insecurity and hunger in the United States. Based on prior research and wide consultation, a survey instrument specifically relevant to U.S. conditions was designed and tested. Through its Current Population Survey (CPS), the U.S. Bureau of the Census has fielded this instrument each year since 1995. A measurement scale was derived from the data through fitting, testing and validating a Rasch scale. The unidimensional Rasch model corresponds to the form of the phenomenon being measured, i.e., the severity of food insufficiency due to inadequate resources as directly experienced and reported in U.S. households. A categorical measure reflecting designated ranges of severity on the scale was constructed for consistent comparison of prevalence estimates over time and across population groups. The technical basis and initial results of the new measure were reported in September 1997. For the 12 months ending April 1995, an estimated 11.9% of U.S. households (35 million persons) were food insecure. Among these, 4.1% of households (with 6.9 million adults and 4.3 million children) showed a recurring pattern of hunger due to inadequate resources for one or more of their adult and/or child members sometime during the period. The new measure has been incorporated into other federal surveys and is being used by researchers throughout the U.S. and Canada. (+info)
Economic determinants and dietary consequences of food insecurity in the United States.
This paper reviews recent research on the economic determinants and dietary consequences of food insecurity and hunger in the United States. The new Current Population Study (CPS) food insecurity and hunger measure shows that hunger rates decline sharply with rising incomes. Despite this strong relationship, confirmed in other national datasets, a one-to-one correspondence between poverty-level incomes and hunger does not exist. In 1995, 13.1% of those in poverty experienced hunger and half of those experiencing hunger had incomes above the poverty level. Panel data indicate that those who are often food insufficient are much more likely than food-sufficient households to have experienced recent events that stress household budgets, such as losing a job, gaining a household member or losing food stamps. Cross-sectional work also demonstrates the importance of food stamps because benefit levels are inversely related to food insufficiency. Concern for the dietary consequences of domestic food insufficiency is well placed; recent research shows that the odds of consuming intakes <50% of the recommended dietary allowance (RDA) are higher for adult women and elderly individuals from food-insufficient households. Preschoolers from food-insufficient households do not consume significantly lower amounts than those from food-sufficient households, but mean intakes for the rest of members in those very same households are significantly lower for the food insufficient. This research highlights the importance of food insecurity and hunger indicators, further validates the use of self-reported measures and points to areas of need for future research and interventions. (+info)
Validity and reproducibility of a quantitative food frequency questionnaire for a cohort study in Japan.
BACKGROUND: A self-administered quantitative food frequency questionnaire (Qx) was developed for a population-based cohort study on cancer in Takayama, Japan. METHODS: The Qx was tested among 58 male and 59 female volunteers. Average daily nutrient intakes for the previous year calculated from the Qx were compared with those from 3-day food records and four 24-h recalls. The Qx was also validated among 37 volunteers by comparing the nutrient intakes calculated from the Qx with 12 1-day food records during a year. We also calculated the intra-class correlation coefficients for various nutrients between the Qx and the second Qx administered by the same volunteers 1 year after the first survey. RESULTS: Pearson correlation coefficients between total energy from the Qx and 3-day records were 0.38 for men and 0.25 for women and those between the Qx and 24-h recalls were 0.19 and -0.02 for men and women, respectively. Correlations between the several nutrients from the Qx and 3-day records ranged from 0.2 to 0.5 for both men and women. These correlations after energy adjustment ranged from 0.2 to 0.6 for men and from 0.1 to 0.7 for women. In general, the correlations for various nutrients between the Qx and 12 1-day records were higher than those described above. The intra-class correlation coefficients ranged from 0.46 to 0.78 in men and from 0.36 to 0.67, except for vitamin C in women. When the information on portion size was excluded, almost all of the above indices showed somewhat lower figures. CONCLUSION: These results suggest that our food frequency questionnaire with portion size information can be used to estimate nutrient intakes of each individual. (+info)
Serum and red blood cell folate concentrations, race, and education: findings from the third National Health and Nutrition Examination Survey.
BACKGROUND: Little is known about the relations between race or ethnicity, educational attainment, and serum and red blood cell folate concentrations. OBJECTIVE: We examined the relation between educational attainment and serum and red blood cell folate concentrations in 8457 white, African American, and Mexican American men and women aged > or = 17 y. DESIGN: We performed a cross-sectional analysis using data from Phase 1 of the third National health and Nutrition Examination Survey (1988-1991). RESULTS: White men had significantly higher adjusted serum and red blood cell folate concentrations (16.9 and 502.6 nmol/L, respectively) than did African American men (15.6 and 423.3 nmol/L, respectively) or Mexican American men (16.0 and 457.0 nmol/L, respectively); white women had significantly higher concentrations (18.4 and 515.9 nmol/L, respectively) than did African American women (16.3 and 415.4 nmol/L, respectively) or Mexican American women (15.9 and 455.7 nmol/L, respectively). For the entire sample, rank correlation coefficients between educational attainment and serum and red blood cell folate were 0.11 and 0.12, respectively, and were larger in white participants than in other participants. No significant linear trends between adjusted serum or red blood cell folate and educational attainment were found. Among participants with > 12 y of education, the mean adjusted concentrations of serum folate were 15% and 18% lower and those of red blood cell were 18% and 22% lower in African American men and women than in white men and women, respectively. CONCLUSIONS: African Americans and Mexican Americans could benefit most from public health programs to boost folate intakes by encouraging increased intake of folate-rich foods and vitamin supplements. (+info)
Serum total homocysteine concentrations in adolescent and adult Americans: results from the third National Health and Nutrition Examination Survey.
BACKGROUND: The elevation of circulating total homocysteine concentrations in a fasting state is associated with an increased risk of occlusive vascular disease. OBJECTIVE: The primary goals of this study were to describe the distribution of serum total homocysteine concentrations in the United States and to test for differences in homocysteine concentrations among sex, age, and race-ethnicity categories. DESIGN: Using surplus sera from phase 2 of the third National Health and Nutrition Examination Survey, we measured serum total homocysteine concentrations for a nationally representative sample of 3766 males and 4819 females aged > or = 12 y. RESULTS: Age-adjusted geometric mean total homocysteine concentrations were 9.6 and 7.9 mmol/L in non-Hispanic white males and females, 9.8 and 8.2 mmol/L in non-Hispanic black males and females, and 9.4 and 7.4 mmol/L in Mexican American males and females, respectively. Age-adjusted geometric mean total homocysteine concentrations were significantly lower in females than in males in each race-ethnicity group (P < 0.01) and were significantly lower in Mexican American females than in non-Hispanic white and non-Hispanic black females (P < 0.01). There was a significant age-sex interaction (P < 0.01), reflecting the fact that homocysteine concentrations in females tended to diverge from those in males at younger ages and converge with those in males at older ages. CONCLUSIONS: The first data on homocysteine concentrations in a nationally representative sample of Americans confirm the age and sex differences reported previously in nonrepresentative samples. These data also indicate that differences between Mexican American and non-Hispanic females may influence circulating homocysteine concentrations. (+info)
Body mass index, weight change, and incidence of self-reported physician-diagnosed arthritis among women.
OBJECTIVES: This study examined the relationship between body mass index (BMI), weight change, and arthritis in women. METHODS: Data were taken from the 1982-1984 National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study of 3617 women, aged 25 to 74 years. RESULTS: Women with a BMI greater than 32 at initial interview were at significantly higher risk of developing arthritis than women with a BMI of 19 to 21.9. Compared with stable-weight women with a BMI of less than 25, women who were obese at initial interview (BMI > 29) and who subsequently maintained their weight or gained more than 10% of their body weight were at significantly higher risk of developing arthritis. CONCLUSIONS: Attaining and maintaining a healthy weight may reduce the risk of developing arthritis. (+info)
Racial and ethnic differences in glycemic control of adults with type 2 diabetes.
OBJECTIVE: To evaluate glycemic control in a representative sample of U.S. adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: The Third National Health and Nutrition Examination Survey included national samples of non-Hispanic whites, non-Hispanic blacks, and Mexican Americans aged > or = 20 years. Information on medical history and treatment of diabetes was obtained to determine those who had been diagnosed with type 2 diabetes by a physician before the survey (n = 1,480). Fasting plasma glucose and HbA1c were measured, and the frequencies of sociodemographic and clinical variables related to glycemic control were determined. RESULTS: A higher proportion of non-Hispanic blacks were treated with insulin and a higher proportion of Mexican Americans were treated with oral agents compared with non-Hispanic whites, but the majority of adults in each racial or ethnic group (71-83%) used pharmacologic treatment for diabetes. Use of multiple daily insulin injections was more common in whites. Blood glucose self-monitoring was less common in Mexican Americans, but most patients had never self-monitored. HbA1c values in the nondiabetic range were found in 26% of non-Hispanic whites, 17% of non-Hispanic blacks, and 20% of Mexican Americans. Poor glycemic control (HbA1c > 8%) was more common in non-Hispanic black women (50%) and Mexican-American men (45%) compared with the other groups (35-38%), but HbA1c for both sexes and for all racial and ethnic groups was substantially higher than normal levels. Those with HbA1c > 8% included 52% of insulin-treated patients and 42% of those taking oral agents. There was no relationship of glycemic control to socioeconomic status or access to medical care in any racial or ethnic group. CONCLUSIONS: These data indicate that many patients with type 2 diabetes in the U.S. have poor glycemic control, placing them at high risk of diabetic complications. Non-Hispanic black women, Mexican-American men, and patients treated with insulin and oral agents were disproportionately represented among those in poor glycemic control. Clinical, public health, and research efforts should focus on more effective methods to control blood glucose in patients with diabetes. (+info)