Validity and reproducibility of an adolescent web-based food frequency questionnaire

OBJECTIVE: To assess the validity and reproducibility of a newly developed, cost-effective, and easy to administer, Web-based food frequency questionnaire (FFQ) for the dietary assessment of adolescents. DESIGN: Cross-sectional validation of a Web-based FFQ, which contained 15 food groups (water; soft drinks, including fruit juice and diet soft drinks; alcoholic beverages; soup; milk and milk products; fruit; sweet and savory snacks/fillings; sauces and fat spreads; breakfast cereals; bread; cheese, fish/eggs/meat; pasta/rice; vegetables; and potatoes). Reference data for validation were 3-day estimated food records. Analyses were done for all participants and for consumers only (consumer in both Web-based FFQ and food record). SUBJECTS/SETTING: A selected group of adolescents (12 to 18 years of age, n=104) from participating secondary schools in Ghent, Belgium. RESULTS: For all participants, the measured intakes of water, fruit, breakfast cereals, fish/eggs/meat, pasta/rice, and potatoes were not significantly different between the two methods. The Spearman correlation for all foods was on average 0.38 (ranging from 0.20 for pasta/rice to 0.64 for breakfast cereals). When analyzed for consumers only, the Web-based FFQ showed significantly lower estimates for soft drinks, sweet and savory snacks/fillings, sauces and fat spreads, cheese, pasta/rice, and vegetables. The average Spearman correlation for all foods collectively was 0.30. When reproducibility of the Web-based FFQ was assessed, the average Spearman correlation coefficient for all foods collectively was 0.62. CONCLUSIONS: Most questions on the 15 food groups had acceptable reproducibility, whereas validation only showed reliable intakes for water, fruit, bread, and fish/eggs/meat. This Web-based FFQ could be a start for development of dietary assessment methods in public health nutrition contexts.     

Validity and reproducibility of a self-administered food frequency questionnaire in older people

This study assesses the validity and reproducibility of a 145-item self-administered food frequency questionnaire (FFQ) in a representative older population aged 63 to 80. Semi-quantitative FFQs were completed by 89% of 3,654 residents attending a community-based eye study in Sydney, Australia. The FFQ's validity was assessed against three, four-day weighed food records (WFRs) completed four months apart by 79 people. A further 152 subjects completed a repeat FFQ about a year after the baseline FFQ, of whom 131 completed a second repeat FFQ about six weeks later. Both short and long-term reproducibility of the FFQ were assessed using data from these subjects. Comparison of the FFQ with the average of the three, four-day weighed food records resulted in energy-adjusted Spearman correlations above 0.5 for most of the nutrients. The proportion of subjects correctly classified to within one quintile category for each nutrient intake ranged from 57% for zinc to 82% for vitamin C, with most nutrients correctly classified within one quintile for about 70% of subjects. Quadratic weighted kappas were reasonable, between 0.3 and 0.5 for most nutrients. The FFQ was highly reproducible in the short term, with correlations for most nutrients about 0.70 to 0.80 and acceptably reproducible in the longer term, with correlations mostly 0.60 to 0.70. The results verity that it is possible to use relatively simple, but comprehensive, self-administered FFQs to study nutrient exposures in large-scale epidemiological studies of the elderly and to expect reasonably high FFQ response rates.     

Validity and reproducibility of the food-frequency questionnaire used in the Shanghai men's health study

We evaluated the validity and reproducibility of the FFQ used in the Shanghai Men's Health Study (SMHS). The study included 195 randomly selected participants of the SMHS who completed one FFQ at baseline, twelve 24-hour dietary recalls (24-HDR) (once a month for twelve consecutive months) and a second FFQ at the end of the study. The FFQ accounted for 88.78% of the foods recorded in the 24-HDR surveys. The validity of the FFQ was evaluated by comparing nutrient and food group intake levels from the second FFQ and the multiple 24-HDR. Correlation coefficients ranged from 0.38 to 0.64 for macronutrients, 0.33 to 0.58 for micronutrients and 0.35 to 0.72 for food groups. Misclassification to opposite quartiles for nutrients and food groups was rare, ranging from 1.5 to 7.7%, while exact agreement rates were between 31.8 and 53.3%. The reliability of the FFQ was assessed by comparing the intake levels from the two FFQ. Correlation coefficients were 0.39 to 0.53 for macronutrients, 0.38 to 0.52 for micronutrients and 0.39 to 0.64 for food groups. Exact agreement rates for quartile distribution were between 31.8 and 49.2%, while misclassification to opposite quartiles was between 1.5 and 6.2%. These data indicate that the SMHS FFQ can reasonably categorise usual intake of nutrients and food groups among men living in urban Shanghai.     

Validity and reproducibility of a food frequency questionnaire for pregnant Finnish women

The authors developed a self-administered 181-item food frequency questionnaire (FFQ) to assess dietary intake during pregnancy for Finnish women from August 1995 to July 1996. In the validation study (n = 113), the data that were collected by using two 5-day food records completed during the eighth month of pregnancy were compared with FFQ data. The intake of foods and nutrients was higher as determined by FFQ than that assessed using food records. Pearson correlation coefficients for nutrients, after adjustment for energy, ranged from 0.19 (vitamin E) to 0.70 (thiamin) and, for foods, from 0.03 (high-fat milk) to 0.84 (low-fat milk). Energy adjustment improved the correlations for nutrients. Correction for attenuation improved correlations for both foods and nutrients. On average, 70% of the foods and 69% of the nutrients fell into the same or adjacent quintiles, according to the FFQ and the food record. In the reproducibility study, 111 women completed the FFQs twice at a 1-month interval. The intraclass correlation coefficients for nutrients ranged from 0.42 (ethanol) to 0.72 (sucrose, riboflavin, and calcium), and for foods, they ranged from 0.44 (ice cream) to 0.91 (coffee). The authors conclude that the FFQ has an acceptable reproducibility and represents a useful tool for categorizing pregnant women according to their dietary intake.     

乳腺癌患者豆类食品食用频率表的信度和效度研究

摘要:目的　对豆类食品食用频率表用于评估乳腺癌患者大豆异黄酮摄入量进行信度和效度研究。方法　以21 d为间隔,采用豆类食品食物频率表对253名正在接受化疗的乳腺癌患者进行两次膳食调查,比较两次结果之间的相关性,评价问卷的信度;以3日膳食记录法作为“标准”,记录乳腺癌患者进行下一化疗疗程前3 d的膳食情况,调查结果进行相关性分析,检测其效度。结果　信度研究中,各种豆类食品的大豆异黄酮以及大豆异黄酮的日均摄入总量均为正相关,相关系数为0.52～0.86,平均值0.69。效度研究中,豆类食品食用频率表与3 d膳食记录相比较,原始数据计算的相关系数为0.14～0.76,均值为0.48,将原始数据经对数转换后,相关系数均值为0.53。结论　豆类食品食用频率表具有较好的效度和信度,在研究乳腺癌患者大豆异黄酮摄入量与乳腺癌之间关系时,豆类食品食用频率表是一个较为理想的测量工具。     

Validity and reproducibility of food frequency questionnaire in Japanese children aged 6 years

The aim of the present study was to evaluate the validity and reproducibility of a food frequency questionnaire (FFQ) for use among young Japanese children. Forty-seven mothers of children aged 6 y completed two 3-d diet records and two FFQs over a 6-mo period. The FFQ asked the mothers how often, on average, their children consumed each of the 162 food items listed and what the usual serving size of each item was during the 6 mo prior to the study. Intakes of macro- and micronutrients were estimated by multiplying the frequency by the serving size for each food item. The validity of the FFQ was assessed by comparison of the two 3-d diet records. The reproducibility of the FFQ was based on the first and second FFQ administrations. The validity correlation ranged from 0.05 for α-tocopherol to 0.59 for retinol. The median correlation was 0.40. The reproducibility correlation was higher than 0.50 for all nutrients. For most nutrients, FFQ had acceptable reproducibility, whereas validity showed low to moderate correlations. Our FFQ could reasonably rank individuals according to dietary intake for epidemiologic studies, although the validity of the questionnaire is limited to specific nutrients.     

Measurement characteristics of the Women's Health Initiative food frequency questionnaire

PURPOSE: The Women's Health Initiative (WHI) is the largest research program ever initiated in the United States with a focus on diet and health. Therefore, it is important to understand and document the measurement characteristics of the key dietary assessment instrument: the WHI food frequency questionnaire (FFQ). METHODS: Data are from 113 women screened for participation in the WHI in 1995. We assessed bias and precision of the FFQ by comparing the intake of 30 nutrients estimated from the FFQ with means from four 24-hour dietary recalls and a 4-day food record. RESULTS: For most nutrients, means estimated by the FFQ were within 10% of the records or recalls. Precision, defined as the correlation between the FFQ and the records and recalls, was similar to other FFQs. Energy adjusted correlation coefficients ranged from 0.2 (vitamin B12) to 0.7 (magnesium) with a mean of 0.5. The correlation for percentage energy from fat (a key measure in WHI) was 0.6. Vitamin supplement use was common. For example, almost half of total vitamin E intake was obtained from supplements. Including supplemental vitamins and minerals increased micronutrient correlation coefficients, which ranged from 0.2 (thiamin) to 0.8 (vitamin E) with a mean of 0.6. CONCLUSIONS: The WHI FFQ produced nutrient estimate, that were similar to those obtained from short-term dietary recall and recording methods. Comparison of WHI FFQ nutrient intake measures to independent and unbiased measures, such as doubly labeled water estimates of energy expenditure, are needed to help address the validity of the FFQ in this population.     

Relative validity of food frequency questionnaire nutrient estimates in the Black Women's Health Study

PURPOSE: The Black Women's Health Study (BWHS) was designed to investigate determinants of health and disease in US black women. More than 64,000 women are enrolled in the BWHS cohort. This study assessed the relative validity of the 68-item food frequency questionnaire (FFQ) used in the BWHS baseline questionnaire. METHODS: Four hundred and eight BWHS enrollees were asked to provide three telephone, 24-hour recalls and one written 3-day food diary over a one-year period. Means and Pearson correlations were computed to compare estimates for energy, total fat, saturated fat, protein, carbohydrate, dietary fiber, calcium, iron, vitamin C, folate, beta-carotene, and vitamin E from the FFQ, recalls, and diaries. RESULTS: Mean energy intake (kcal) was higher for the diary (1716) than the FFQ (1601) or recalls (1510). Other nutrient estimates (% kcal or per 1000 kcal) were similar across methods, except beta-carotene (FFQ higher). Correlations (energy-adjusted, except for energy, and corrected for intraperson variation) between the FFQ and the recalls were higher than for the diary data and were between 0.5 and 0.8, except for energy and vitamin E (both <0.3). CONCLUSION: The BWHS FFQ will support meaningful analyses of diet-health associations for 10 of the 11 energy-adjusted nutrient intake variables analyzed.     

广州地区食物频率问卷信度和效度研究

目的对广州地区人群营养与慢性病研究中使用的食物频率问卷(food frequency questionnaire,FFQ)进行信度和效度研究。方法间隔2～5周进行两次FFQ调查,比较两次结果的相关性,检验问卷的信度。在3个月内进行3次三日膳食回顾和1次FFQ调查,用3次三日膳食回顾的平均结果与FFQ的相关性分析结果评价FFQ的内容效度。结果 (1)信度研究中膳食能量和10种营养素均为显著性正相关,以原始数值计算的相关系数(r)为0.379～0.740,平均值为0.609;经自然对数转换后的平均r为(0.589±0.123);校正能量后平均r为(0.511±0.139)。(2)效度研究中FFQ与三日膳食回顾法的膳食能量和10种营养素均为显著正相关,以原始数值计算的r为0.318～0.782,平均值0.439;自然对数转换后的平均r为(0.448±0.122);校正能量后平均r为(0.427±0.132)。(3)食物和营养素的信度研究一致率分别为70.3%和100.0%,营养素的效度一致率为100.0%。结论所制订的广州地区FFQ具有较好的信度和效度,是研究广州市人群营养与慢性病关系较为理...     

Validity and reproducibility of a food frequency questionnaire by cognition in an older biracial sample

It is not currently known how dietary assessment in older persons is affected by cognition. In a 1997-2000 study, the authors assessed the validity and reproducibility of a modified Harvard self-administered food frequency questionnaire (SFFQ) among 118 Black and 114 White randomly selected participants, aged 68-99 years, of the Chicago Health and Aging Project. Participants completed multiple 24-hour dietary recall interviews (mean=3.6) over 12 months and two SFFQs in the first and 12th months. The average energy-adjusted intraclass correlation coefficient for 15 nutrients was 0.59 for 1-year reproducibility in nutrient intake levels assessed by the SFFQ. The average energy-adjusted Pearson correlation coefficient was 0.46 for comparative validity between nutrient intake levels on the SFFQ and the dietary recalls. SFFQ reproducibility was higher among men, and comparative validity with the dietary recalls was higher among women. There were no remarkable differences in the correlations by age, race, educational level, presence of chronic conditions, or cognitive ability. The modified Harvard SFFQ is a reasonable method of dietary assessment even in a population of older persons, some of whom are at advanced age, have chronic health conditions, and have cognitive impairment.     

Validity and reproducibility of a semi-quantitative food frequency questionnaire for use among pregnant women in rural China

A longitudinal study was conducted to validate a 68-item semi-quantitative food-frequency questionnaire (FFQ) for assessing nutrient intake among pregnant women in rural China. The interview administrated FFQs were conducted at the start of the third trimester (FFQ1) and repeated three months later prior to delivery (FFQ2), and compared with six repeated 24-hour recalls collected between the FFQs. From June to September 2004, 125 women at 23 to 26 weeks of gestation were recruited into the study in two rural counties in Shaanxi province, China. Pearson correlation coefficients for crude nutrients assessed by FFQ1 and FFQ2 had a mean of 0.46, and ranged from 0.31 for thiamin to 0.61 for fat. Pearson correlation coefficients estimated by FFQ2 and 24-hour recalls had a mean of 0.62 for all nutrients, and ranged from 0.53 for cholesterol and carotene to 0.70 for alpha-vitamin E and potassium. De-attenuated coefficients had a mean of 0.69 for all nutrients, and ranged from 0.58 for cholesterol to 0.77 for alpha- vitamin E. Bland-Altman plots revealed significant relationships between the difference and the average of the two methods with larger differences at higher average intakes. On average, 74% of participants were classified into the same or adjacent nutrient intake quintiles, while 1% were grossly misclassified to opposite quintiles. In conclusion, this FFQ has adequate reproducibility and validity for most nutrients but would benefit from the addition of wheat porridge to ensure it is suitable for assessing dietary intake in pregnant women in rural China.     

Reproducibility and validity of the Shanghai Women's Health Study physical activity questionnaire

In this investigation, the authors evaluated the reproducibility and validity of the Shanghai Women's Health Study (SWHS) physical activity questionnaire (PAQ), which was administered in a cohort study of approximately 75,000 Chinese women aged 40-70 years. Reproducibility (2-year test-retest) was evaluated using kappa statistics and intraclass correlation coefficients (ICCs). Validity was evaluated by comparing Spearman correlations (r) for the SWHS PAQ with two criterion measures administered over a period of 12 months: four 7-day physical activity logs and up to 28 7-day PAQs. Women were recruited from the SWHS cohort (n = 200). Results indicated that the reproducibility of adolescent and adult exercise participation (kappa = 0.85 and kappa = 0.64, respectively) and years of adolescent exercise and adult exercise energy expenditure (ICC = 0.83 and ICC = 0.70, respectively) was reasonable. Reproducibility values for adult lifestyle activities were lower (ICC = 0.14-0.54). Significant correlations between the PAQ and criterion measures of adult exercise were observed for the first PAQ administration (physical activity log, r = 0.50; 7-day PAQ, r = 0.62) and the second PAQ administration (physical activity log, r = 0.74; 7-day PAQ, r = 0.80). Significant correlations between PAQ lifestyle activities and the 7-day PAQ were also noted (r = 0.33-0.88). These data indicate that the SWHS PAQ is a reproducible and valid measure of exercise behaviors and that it demonstrates utility in stratifying women by levels of important lifestyle activities (e.g., housework, walking, cycling).     

Validity and reproducibility of a food frequency interview in a Multi-Cultural Epidemiology Study

PURPOSE: There is limited support for the validity and reproducibility of dietary assessment in culturally diverse populations. The goal of this study was to evaluate the comparative validity and reproducibility of a Food Frequency Questionnaire (FFQ) used in the observational, multi-cultural Insulin Resistance Atherosclerosis Study (IRAS). METHODS: Women (n = 186) were approximately equally distributed by ethnicity from one urban center (African Americans and non-Hispanic whites) and one rural center (Hispanics and non-Hispanic whites). The IRAS FFQ was modified from the National Cancer Institute Health Habits and History Questionnaire to include ethnic and regional foods. Validity was assessed by comparing dietary values, including supplements, obtained from the FFQ to the average intake estimated from a series of 8 24-hour dietary recalls collected by telephone over the same 1-year period. Reproducibility was assessed among women who reported no change in their usual diet (n = 133) by comparing data from the original IRAS FFQ (in-person) with the FFQ administered for the validity study (two to four years later, by telephone). RESULTS: Correlation coefficients for validity were statistically significant for most nutrients (mean r = 0.62 urban non-Hispanic white, 0.61 rural non-Hispanic whites, 0.50 African American, 0.41 Hispanic) and did not differ among subgroups of obesity or diabetes status. The median correlation coefficient for the total sample was 0.49. Correlations were lower for women with less than 12 years of education (mean r = 0.30; median r = 0.25). The lower correlations among Hispanics was largely explained by the lower educational attainment in that sample. For reproducibility, the mean correlation for nutrients evaluated was r = 0.62 (median r = 0.63) and did not differ for subgroups. CONCLUSIONS: Although educational attainment must be considered, the IRAS FFQ appears to be reasonably valid and reliable in a diverse cohort.     

Validation and reproducibility of an Australian caffeine food frequency questionnaire

The aim of this study was to measure validity and reproducibility of a caffeine food frequency questionnaire (C-FFQ) developed for the Australian population. The C-FFQ was designed to assess average daily caffeine consumption using four categories of food and beverages including; energy drinks; soft drinks/soda; coffee and tea and chocolate (food and drink). Participants completed a seven-day food diary immediately followed by the C-FFQ on two consecutive days. The questionnaire was first piloted in 20 adults, and then, a validity/reproducibility study was conducted (n?=?90 adults). The C-FFQ showed moderate correlations (r?=?.60), fair agreement (mean difference 63?mg) and reasonable quintile rankings indicating fair to moderate agreement with the seven-day food diary. To test reproducibility, the C-FFQ was compared to itself and showed strong correlations (r?=?.90), good quintile rankings and strong kappa values (κ?=?0.65), indicating strong reproducibility. The C-FFQ shows adequate validity and reproducibility and will aid researchers in Australia to quantify caffeine consumption.     

Validity and reproducibility of an interviewer-administered food frequency questionnaire in Austrian adults at risk of or with overt diabetes mellitus

Food frequency questionnaires (FFQs) provide an inexpensive tool for dietary assessment. Given the scarcity of data on their validity for nutritional analysis in persons with overt diabetes mellitus or with increased risk of diabetes (relatives of patients with diabetes), this study tests the hypothesis that an FFQ, adapted to local dietary habits, yields a reliable estimate of nutrient intake when compared with 7-day food record (7DR) in healthy, prediabetes, and diabetes cohorts. One hundred three volunteers (50 persons with overt diabetes mellitus, 24 relatives of patients with diabetes, and 29 nondiabetic individuals without a family history of diabetes) completed both FFQ and 7DR. A second FFQ was completed by 100 of these volunteers after 3 months to evaluate its reproducibility. Data were compared by correlation and Bland-Altman analyses. Across the entire group, estimates for gram intakes of nutrients and total energy were associated with wide limits of agreement between FFQ and 7DR (correlation coefficients, 0.23-0.72; P < .02). Compared with 7DR, the FFQ overestimated intakes of saturated fat in the entire group (+6.6 ± 14 g; P < .001) and in persons with overt diabetes mellitus (+7.6 ± 15 g; P < .001) but underestimated protein intake in relatives of patients with diabetes (−16.36 ± 31 g; P = .01). The repeated FFQ revealed variable agreement (correlation coefficients, 0.34-0.72; P < .001) and underestimated (P < .01) macronutrient and total energy intakes, with slightly better performance in persons with overt diabetes mellitus and relatives of patients with diabetes than in nondiabetic individuals without a family history of diabetes. Hence, the FFQ allows measuring intakes of total energy and macronutrients in prediabetes and diabetes cohorts but reveals limitations when assessing dietary composition.     

Validity and reproducibility of an iodine‐specific food frequency questionnaire to estimate dietary iodine intake in older Australians

Aim: Iodine deficiency, which has adverse effects on health has re‐emerged in Australia. The present study aimed to develop and validate a novel iodine‐specific food frequency questionnaire for use in older Australians. Methods: A 49‐item food frequency questionnaire that included iodine‐rich foods was constructed and administered in 84 men and women aged 60–95 years with normal cognitive function. Dietary iodine intake assessed by the food frequency questionnaire was validated against three repeated 24‐hour dietary recalls. Urinary spot iodine concentrations were selected as iodine intake biomarker. Agreement between the two dietary methods was determined using a Bland–Altman plot and intra‐class coefficients. Correlations between dietary and urinary iodine were assessed. Forty‐three participants repeated the questionnaire after 9 months for reproducibility. Results: Mean iodine intake measured by the food frequency questionnaire and 24‐hour dietary recalls did not differ significantly (P= 0.870). The two methods were moderately correlated (r = 0.377; P < 0.05) and the Bland–Altman plots demonstrated an acceptable level of agreement (P= 0.870). Despite an association (r = 0.230; P < 0.05) between urinary iodine concentrations and 24‐hour dietary recalls, the food frequency questionnaire was not associated with urinary iodine concentration (r = 0.094; P= 0.40). The method of triads showed coefficients of 0.238 (urinary iodine), 0.953(food frequency questionnaire), 0.396 (24‐hour dietary recall) with the unknown true value. Conclusion: A short food frequency questionnaire to assess habitual dietary iodine intake in older Australians has been shown to be valid at the group level with regard to categorising individuals according to their habitual iodine intake. Reproducibility of the food frequency questionnaire remains to be demonstrated.