Relative validity of an intelligent ordering system to estimate dietary intake among university students from a medical school in Shanghai, China.

BACKGROUND: Dietary assessment methods have limitations in capturing real-time eating behaviour accurately. Equipped with automated dietary-data-collection capabilities, the "intelligent ordering system" (IOS) has potential applicability in obtaining long-term consecutive, relatively detailed on-campus dietary records among university students with little resource consumption. We investigated (1) the relative validity of IOS-derived nutrient/food intakes compared to those from the 7-day food diary (7DFD); (2) whether including a supplemental food frequency questionnaire (SFFQ) improves IOS accuracy; and (3) sex differences in IOS dietary intake estimation. METHODS: Medical students (n = 221; age = 22.2 ± 2.4 years; 38.5% male and 61.5% female) completed the 7DFD and SFFQ. During the consecutive 7-day survey period, students weighed and photographed each meal before and after consumption. Then, students reviewed their 3-month diet and completed the SFFQ, which includes eight underprovided school-canteen food items (e.g., dairy, fruits, nuts). Meanwhile, 9385 IOS dietary data entries were collected. We used Spearman coefficients and linear regression models to estimate the associations among the different dietary intake assessment methods. Individual- and group-level agreement was assessed using the Wilcoxon signed-rank test, cross-classification, and Bland‒Altman analysis. RESULTS: IOS mean daily energy, protein, fat, and carbohydrate intake estimations were significantly lower (-15-20%) than those of the 7DFD. The correlation coefficients varied from 0.52 (for added sugar) to 0.88 (for soybeans and nuts), with fruits (0.37) and dairy products (0.29) showing weaker correlations. Sixty-two (milk and dairy products) to 97% (soybeans and nuts) of participants were classified into the same or adjacent dietary intake distribution quartile using both methods. The energy and macronutrient intake differences between the IOS + SFFQ and 7DFD groups decreased substantially. The separate fruit intake measurements from each assessment method did not significantly differ from each other (p > 0.05). IOS and IOS + SFFQ regression models generally yielded higher R2 values for males than for females. CONCLUSION: Despite estimation differences, the IOS can be reliable for medical student dietary habit assessment. The SFFQ is useful for measuring consumption of foods that are typically unavailable in school cafeterias, improving the overall dietary evaluation accuracy. The IOS assessment was more accurate for males than for females.

Assessing the relative validity of a web-based self-administered 24-hour dietary recall in a Canadian adolescent's population.

BACKGROUND: Healthy eating habits at a young age are crucial to support growth and development and good general health. In this context, monitoring youth dietary intakes adequately with valid tools is important to develop efficient interventions and identify groups that are more at risk of inadequate intakes. This study aimed to assess the relative validity of the self-administered web-based 24-h dietary recall (R24W) for evaluating energy and nutrient intakes among active adolescents. METHODS: Participants were invited to complete one interviewer-administered 24-h dietary dietary recall and the R24W on up to three occasions within one month. A total of 272 French-speaking active adolescents aged 12 to 17 years from the province of Québec were invited to complete three R24W and one interview-administered 24-h recall. Student's t-test and correlations were conducted on sex-adjusted data. Percent differences, cross-classification (percentage of agreement), weighted Kappa and Bland-Altman plots were calculated. RESULTS: Mean (SD) energy intake from the R24W was 8.8% higher than from the interview-administered 24-h dietary recall (2558 kcal ± 1128 vs. 2444 kcal ± 998, p < 0.05). Significant differences in mean nutrient intake between the R24W and the interview-administered 24-h dietary recall ranged from 6.5% for % E from fat (p < 0.05) to 25.2% for saturated fat (p < 0.001), i.e., higher values with R24W. Sex-adjusted correlations were significant for all nutrients except for % E from proteins and thiamin (range: 0.24 to 0.52, p < 0.01). Cross-classification demonstrated that 36.6% of the participants were classified in the same fourth with both methods, 39.6% in the adjacent fourth, and 5.7% misclassified. Bland-Atman plots revealed proportional bias between the two methods for 7/25 nutrients. Completing at least two recalls with the R24W increased the precision of intake estimates. CONCLUSION: These data suggest that the R24W presents an acceptable relative validity compared to a standard interview-administered 24-h recall for estimating energy and most nutrients in a cohort of French-speaking adolescents from the province of Québec.

Dietary Intake Assessment Using a Novel, Generic Meal-Based Recall and a 24-Hour Recall: Comparison Study.

BACKGROUND: Dietary intake assessment is an integral part of addressing suboptimal dietary intakes. Existing food-based methods are time-consuming and burdensome for users to report the individual foods consumed at each meal. However, ease of use is the most important feature for individuals choosing a nutrition or diet app. Intakes of whole meals can be reported in a manner that is less burdensome than reporting individual foods. No study has developed a method of dietary intake assessment where individuals report their dietary intakes as whole meals rather than individual foods. OBJECTIVE: This study aims to develop a novel, meal-based method of dietary intake assessment and test its ability to estimate nutrient intakes compared with that of a web-based, 24-hour recall (24HR). METHODS: Participants completed a web-based, generic meal-based recall. This involved, for each meal type (breakfast, light meal, main meal, snack, and beverage), choosing from a selection of meal images those that most represented their intakes during the previous day. Meal images were based on generic meals from a previous study that were representative of the actual meal intakes in Ireland. Participants also completed a web-based 24HR. Both methods were completed on the same day, 3 hours apart. In a crossover design, participants were randomized in terms of which method they completed first. Then, 2 weeks after the first dietary assessments, participants repeated the process in the reverse order. Estimates of mean daily nutrient intakes and the categorization of individuals according to nutrient-based guidelines (eg, low, adequate, and high) were compared between the 2 methods. P values of less than .05 were considered statistically significant. RESULTS: In total, 161 participants completed the study. For the 23 nutrient variables compared, the median percentage difference between the 2 methods was 7.6% (IQR 2.6%-13.2%), with P values ranging from <.001 to .97, and out of 23 variables, effect sizes for the differences were small for 19 (83%) variables, moderate for 2 (9%) variables, and large for 2 (9%) variables. Correlation coefficients were statistically significant (P<.05) for 18 (78%) of the 23 variables. Statistically significant correlations ranged from 0.16 to 0.45, with median correlation of 0.32 (IQR 0.25-0.40). When participants were classified according to nutrient-based guidelines, the proportion of individuals who were classified into the same category ranged from 52.8% (85/161) to 84.5% (136/161). CONCLUSIONS: A generic meal-based method of dietary intake assessment provides estimates of nutrient intake comparable with those provided by a web-based 24HR but with varying levels of agreement among nutrients. Further studies are required to refine and improve the generic recall across a range of nutrients. Future studies will consider user experience including the potential feasibility of incorporating image recognition of whole meals into the generic recall.

Digital Food Frequency Questionnaire Assessing Adherence to the Norwegian Food-Based Dietary Guidelines and Other National Lifestyle Recommendations: Instrument Validation Study.

BACKGROUND: Valid assessment tools are needed when investigating adherence to national dietary and lifestyle guidelines. OBJECTIVE: The relative validity of the new digital food frequency questionnaire, the DIGIKOST-FFQ, against 7-day weighed food records and activity sensors was investigated. METHODS: In total, 77 participants were included in the validation study and completed the DIGIKOST-FFQ and the weighed food record, and of these, 56 (73%) also used the activity sensors. The DIGIKOST-FFQ estimates the intake of foods according to the Norwegian food-based dietary guidelines (FBDGs) in addition to lifestyle factors. RESULTS: At the group level, the DIGIKOST-FFQ showed good validity in estimating intakes according to the Norwegian FBDG. The median differences were small and well below portion sizes for all foods except "water" (median difference 230 g/day). The DIGIKOST-FFQ was able to rank individual intakes for all foods (r=0.2-0.7). However, ranking estimates of vegetable intakes should be interpreted with caution. Between 69% and 88% of the participants were classified into the same or adjacent quartile for foods and between 71% and 82% for different activity intensities. The Bland-Altman plots showed acceptable agreements between DIGIKOST-FFQ and the reference methods. The absolute amount of time in "moderate to vigorous intensity" was underestimated with the DIGIKOST-FFQ. However, estimated time in "moderate to vigorous intensity," "vigorous intensity," and "sedentary time" showed acceptable correlations and good agreement between the methods. The DIGIKOST-FFQ was able to identify adherence to the Norwegian FBDG and physical activity recommendations. CONCLUSIONS: The DIGIKOST-FFQ gave valid estimates of dietary intakes and was able to identify individuals with different degrees of adherence to the Norwegian FBDG and physical activity recommendations. Moderate physical activity was underreported, water was overreported, and vegetables showed poor correlation, which are important to consider when interpreting the data. Good agreement was observed between the methods in estimating dietary intakes and time in "moderate to vigorous physical activity," "sedentary time," and "sleep."

Overshadowing, but not relative validity, between the elements of an outcome during human associative learning.

Overshadowing and relative validity constitute two phenomena that inspired the development of the Rescorla-Wagner model in 1972. They demonstrate that cues will interact with one another for an association with the presence or absence of an outcome. Here, three experiments sought to explore whether these two effects extended to outcomes using a food allergist paradigm with human participants. In Experiment 1 (overshadowing) participants received trials in which a cue was followed by a compound of two outcomes (A-O1O2). Test trials revealed that participants learned less about the A-O2 association than they did between a control cue C, which had been paired with O2 in isolation (C-O2) in training - thus demonstrating an outcome overshadowing effect. In Experiment 2 (relative validity) participants received true discrimination trials, in which A was paired with an O1O3 compound and B was paired with an O2O3 compound, and pseudo discrimination trials, in which C and D were paired on 50% of the trials with an O4O6 compound and on the remaining trials with an O5O6 compound. Consequently, O3 is less well predicted by A and B relative to O1 and O2, whereas O6 is equally well predicted by C and D relative to O4 and O5. Despite the relative validity of A and B for O3 being less than the relative validity of C and D for O6, the ratings of A and B for O3 were the same as C and D for O6. This failure to observe an outcome relative validity effect was reproduced in Experiment 3, which replicated Experiment 2, but with an adjustment made to the number of training trials given to participants. These results are discussed in terms of a real-time development of the Rescorla-Wagner model provided by Wagner (1981).

Relative validity of the Planetary Health Diet Index by comparison with usual nutrient intakes, plasma food consumption biomarkers, and adherence to the Mediterranean diet among European adolescents: the HELENA study.

PURPOSE: The EAT-Lancet Commission proposed an evidence-based global reference diet to improve human health within planetary boundaries. Recently, the Planetary Health Diet Index (PHDI) was developed based on the EAT-Lancet recommendations and validated among Brazilian adults. However, the relative validity of the PHDI in adolescents has yet to be assessed. Thus, we aimed to evaluate the relative validity of the PHDI in European adolescents. METHODS: We used cross-sectional data from 1804 adolescents (12.5-17.5 years) enrolled in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. The PHDI (0-150 points) was calculated based on dietary intake data from two non-consecutive 24-h dietary recalls. Associations between the PHDI and usual nutrient intakes, plasma food consumption biomarkers, and adherence to the Mediterranean diet were evaluated using multivariable-adjusted mixed-effects linear regression models. RESULTS: Higher PHDI score was associated with greater intakes of nutrients predominantly from plant-source foods, such as vegetable protein, vitamin E, and folate and with lower intake of nutrients predominately from animal-source foods, such as total and saturated fat, cholesterol, and animal protein. Furthermore, a higher PHDI score was also positively associated with plasma ß-carotene, vitamin C, vitamin D, folate, and ferritin concentrations, while negatively associated with trans-fatty acids concentration. Moreover, higher PHDI was related to a greater adherence to the Mediterranean dietary pattern. CONCLUSIONS: The PHDI showed good relative validity among adolescents in the HELENA study. Hence, future research should assess adherence to the PHDI and long-term health outcomes.

Development and validation of a novel food exchange system for Chinese pregnant women.

BACKGROUND: The dietary nutritional status of pregnant women is critical for maintaining the health of both mothers and infants. Food exchange systems have been employed in the nutritional guidance of patients in China, although their application in the dietary guidance of healthy pregnant women is quite limited. This study aimed to develop a novel food exchange system for Chinese pregnant women (NFES-CPW) and evaluate the relative validation of its application. METHODS: NFES-CPW covers approximately 500 types of food from ten categories and has more elaborate food portion sizes. It established a recommendation index for guiding food selection and used energy, water content, and protein as the exchange basis to balance the supply of energy and important nutrients throughout pregnancy. Furthermore, dietitians used the NFES-CPW and traditional food exchange system to generate new recipes based on the sample recipe. There were 40 derived recipes for each of the two food exchange methods. The food consumption, energy, and key nutrients of each recipe were calculated, and the differences between the two food exchange systems were compared using the Wilcoxon rank sum test or the Chi-square test. RESULTS: The results revealed that compared to those derived from traditional food exchange system, the NFES-CPW derived recipes had a better dietary structure, as evidenced by the intakes of whole-grain cereals, beans excluding soybeans, potatoes, fruits, fish, shrimp and shellfish, as well as eggs (P < 0.05), which were more conducive to reaching the recommended range of balanced dietary pagoda. After calculating energy and nutrients, although these two food exchange systems have similar effects on the dietary energy and macronutrient intake of pregnant women, the intake of micronutrients in NFES-CPW derived recipes was significantly higher than that from the traditional food exchange system, which was more conducive to meeting the dietary requirements of pregnant women. The outstanding improvement are primarily vitamin A, vitamin B2, folic acid, vitamin B12, vitamin C, calcium, iron, and iodine (P < 0.05). Moreover, when compared to recipes obtained from the traditional food exchange system, the error ranges of energy and most nutrients were significantly reduced after employing the NFES-CPW. CONCLUSIONS: Therefore, NFES-CPW is an appropriate tool that adheres to Chinese dietary characteristics and can provide suitable dietary guidance to pregnant women.

Comparison of dietary share of ultra-processed foods assessed with a FFQ against a 24-h dietary recall in adults: results from KNHANES 2016.

OBJECTIVE: To evaluate the performance of an FFQ for estimating dietary contributions of NOVA groups to individuals' diets with a specific focus on ultra-processed foods (UPF) compared with a single 24-h dietary recall (24HR). DESIGN: All consumed foods and beverages assess with both a 109-item FFQ and a single 24HR were classified into one of four NOVA groups: natural or minimally processed foods (MPF), processed culinary ingredients (PCI), processed foods (PF) and UPF. The contributions of each NOVA group to daily intakes of energy, protein, fat, saturated fat, carbohydrate, fibre and Na were expressed as crude intake, energy-adjusted intake and percentage intake. Mean differences, correlation coefficients and joint classification were calculated for intakes of energy and nutrients from each NOVA group between the FFQ and the 24HR. SETTING: The Korea National Health and Nutrition Examination Survey 2016. PARTICIPANTS: Adults aged 19-64 years (n 3189). RESULTS: The smallest group-mean differences between the two methods were observed in UPF (2-40 %). The greatest average Pearson's correlation coefficients between the FFQ and 24HR were shown in dietary contributions of UPF (r = 0·22-0·25 for MPF; r = 0·02-0·05 for PCI; r = 0·11-0·18 for PF; r = 0·26-0·30 for UPF). The greatest agreement in quartile classification between the FFQ and the 24HR was observed in dietary contributions of UPF (70·0-71·5 % for MPF; 64·2-68·8 % for PCI; 66·9-69·2 % for PF; 71·8-73·9 % for UPF). CONCLUSIONS: The use of the FFQ for estimating absolute intake of UPF may not be encouraged in its current form, but it still may be used for relative comparisons such as quantile categorisation.

Reproducibility and relative validity of a semi-quantitative food frequency questionnaire for the Chinese lactating mothers.

BACKGROUND: The dietary nutritional status of the lactating mothers is related to maternal health and has a significant impact on the growth and development of infants through the secretion of breast milk. The food frequency questionnaire (FFQ) is the most cost-effective dietary assessment method that can help obtain information on the usual dietary pattern of participants. Until now, the FFQs have been used for different populations in China, but there are few FFQs available for the lactating mothers. We aimed to develop a semi-quantitative, 156-item FFQ for the Chinese lactating mothers, and evaluate its reproducibility and relative validity. METHODS: A total of 112 lactating mothers completed two FFQs and one 3-d dietary record (3DR). The first FFQ (FFQ1) was conducted during postpartum at 60-65 days and the second FFQ (FFQ2) during subsequent follow-up at 5 weeks. The 3DR was completed with portion sizes assessed using photographs taken by the respondent before and after eating (instant photography) 1 week after FFQ1. RESULTS: For reproducibility, the Spearman's correlation coefficients for food ranged from 0.34 to 0.68, and for nutrients from 0.25 to 0.61. Meanwhile, the intra-class correlation coefficients for food ranged from 0.48 to 0.87, and for nutrients from 0.27 to 0.70. For relative validity, the Spearman's correlation coefficients for food ranged from 0.32 to 0.56, and for nutrients from 0.23 to 0.72. The energy-adjusted coefficients for food ranged from 0.26 to 0.55, and for nutrients from 0.22 to 0.47. Moreover, the de-attenuation coefficients for food ranged from 0.34 to 0.67, and for nutrients from 0.28 to 0.77. The Bland-Altman plots also showed reasonably acceptable agreement between the two methods. CONCLUSIONS: This FFQ is a reasonably reproducible and a relative valid tool for assessing dietary intake of the Chinese lactating mothers.

Relative Validity of Starch and Sugar Intake in Japanese Adults as Estimated With Comprehensive and Brief Self-Administered Diet History Questionnaires.

BACKGROUND: In Japan, large-scale epidemiological studies on starch and sugar intake are scarce, mainly due to a lack of a suitable assessment tool. We examined the relative validity of two widely-used dietary assessment questionnaires for Japanese adults, the comprehensive Diet History Questionnaire (DHQ) and the brief DHQ (BDHQ), for estimating the intake of starch and 10 types of sugars: total sugar, sucrose, maltose, lactose, trehalose, glucose, fructose, galactose, and added and free sugars. METHODS: A total of 92 women and 92 men completed 4-day weighed dietary records (DRs) besides the DHQ and BDHQ in each of the four seasons. For each method, starch and sugar intake was calculated according to a recently developed food composition database on starch and sugars for Japanese food items. RESULTS: For most of the carbohydrate variables examined, the median energy-adjusted intake derived from the first DHQ and BDHQ (DHQ1 and BDHQ1, respectively) significantly differed from those derived from the 16-day DRs in both sexes. Spearman correlation coefficients between the 16-day DRs and DHQ1 were acceptable (≥0.31) for all variables (0.31-0.67), except for maltose and trehalose in women (≤0.29). For BDHQ1, the correlations were also acceptable for all variables (0.32-0.64), except for maltose (≤0.26) and galactose (≤0.06). Similar results were observed for the mean of four DHQs and BDHQs. CONCLUSIONS: This study indicated a reasonable ranking ability of DHQ and BDHQ for the intake of starch and most sugars examined, despite a poor ability to estimate the intake at the both group and individual levels.

Assessing Emotional Functioning with Increased Power: Relative Validity of a Customized EORTC Short Form in the International ACTION Trial.

OBJECTIVES: There is a need to improve the assessment of emotional functioning (EF). In the international Advance Care Planning: an Innovative Palliative Care Intervention to Improve Quality of Life in Cancer Patients - a Multi-Centre Cluster Randomized Clinical Trial (ACTION) trial involving patients with advanced cancer, EF was assessed by a customized 10-item short form (EF10). The EF10 is based on the European Organisation for Research and Treatment of Cancer (EORTC) EF item bank and has the potential for greater precision than the common EORTC Quality of Life Questionnaire Core 30 four-item scale (EF4). We assessed the relative validity (RV) of EF10 compared with EF4. METHODS: Patients from Belgium, Denmark, Italy, the Netherlands, Slovenia, and the United Kingdom completed EF10 and EF4, and provided data on generic quality of life, coping, self-efficacy, and personal characteristics. Based on clinical and sociodemographic variables and questionnaire responses, 53 "known groups" that were expected to differ were formed, for example, females versus males. The EF10 and EF4 were first independently compared within this known group, for example, the EF10 score of females vs the EF10 score of males. When these differences were significant, the RV was calculated for the comparison of the EF10 with the EF4. RESULTS: A total of 1028 patients (57% lung, 43% colorectal cancer) participated. Forty-five of the 53 known-groups comparisons were significantly different and were used for calculating the RV. In 41 of 45 (91%) comparisons, the RV was more than 1, meaning that EF10 had a higher RV than EF4. The mean RV of EF10 compared with that of EF4 was 1.41, indicating superior statistical power of EF10 to detect differences in EF. CONCLUSIONS: Compared with EF4, EF10 shows superior power, allowing a 20% to 34% smaller sample size without reducing power, when used as a primary outcome measure.

Relative validity of brief-type self-administered diet history questionnaire among very old Japanese aged 80 years or older.

OBJECTIVE: Dietary questionnaires for assessing dietary intakes among populations of individuals aged 80 years or older (the very old) are very limited. We examined the relative validity of forty-three nutrients and twenty-seven food groups estimated by a brief-type self-administered diet history questionnaire (BDHQ) targeting very old Japanese, using semi-weighed dietary records (DR) as a reference. DESIGN: Between June and August 2012 and between June 2015 and February 2016, a three-day non-consecutive DR (at two-week intervals) and a BDHQ were completed. SETTING: Tokyo, the capital prefecture of Japan. SUBJECTS: Eighty very old Japanese (thirty-six men and forty-four women) aged 82-94 years. RESULTS: The median intakes of 40-70 % of the crude and energy-adjusted nutrients estimated by the BDHQ were significantly different from those estimated by the DR. The median Spearman's correlation coefficient of nutrient intakes between the BDHQ and the DR was 0·39-0·46. About half (48-56 %) of the food groups were significantly different in terms of the median intakes estimated by the BDHQ and the DR in crude and energy-adjusted values. The median Spearman's correlation coefficient between the BDHQ and the DR was 0·45-0·48. CONCLUSIONS: Acceptable Spearman's correlations (≥0·3) were obtained for many dietary intakes among the very old Japanese population. The BDHQ is a good candidate for epidemiological studies among very old Japanese, although, for some nutrients and food groups, the difficulty of estimating accurate median intakes is one of the limitations for the tool. Further efforts to enhance the validity of the BDHQ for very old populations are needed.

Feasibility and relative validity of a digital photo-based dietary assessment: results from the Nutris-Phone study.

OBJECTIVE: For dietary assessment, mobile devices with a camera can be used as an alternative to hand-written paper records. The Nutritional Tracking Information Smartphone (Nutris-Phone) study aimed to examine relative validity and feasibility of a photo-based dietary record in everyday life. DESIGN: Parallel to the photo-based technique, a weighed record was performed. Participant satisfaction was assessed by questionnaire. A trained nutrition scientist evaluated portion sizes and nutrient content was calculated (DGExpert). Spearman correlation and Bland-Altman analyses were applied. SETTING: Healthy, non-pregnant volunteers (≥18 years) without intent to lose weight recruited at Ulm University, Germany. SUBJECTS: Sixty-six participants (36 % males, median age 22·0 (interquartile range 20·0-25·0) years) took pictures of foods and beverages consumed with a commercially available mobile phone. RESULTS: Significant correlation between the photo-based and weighed record was observed: energy (r=0·991), carbohydrate (r=0·980), fat (r=0·972), protein (r=0·988), fibre (r=0·941). Bland-Altman analyses indicated comparable means and acceptable 95 % limits of agreement (energy: -345·2 to 302·9 kJ (-82·5 to 72·4 kcal); carbohydrate: -15·2 to 13·1 g; fat: -6·4 to 6·4 g; protein: -5·9 to 5·6 g; fibre: -2·7 to 2·5 g). However, with increasing intake level, underestimation by the digital method was present (except for fat, all P<0·01). Over 80 % of participants were satisfied with the photo-based record. In nearly 90 %, technical implementation was without major problems. CONCLUSIONS: Compared with a weighed record, the photo-based dietary record seems to be valid, feasible and user-friendly to estimate energy, macronutrient and fibre intakes, although a systematic bias with increasing levels of intake should be kept in mind.

Evaluation of the online Beverage Frequency Questionnaire (BFQ).

BACKGROUND: The contribution of beverages to overall diet is of increasing interest to researchers and policymakers, particularly in terms of consumption of drinks high in added sugars; however, few tools to assess beverage intake have been developed and evaluated. This study aimed to evaluate the relative validity of a new online Beverage Frequency Questionnaire (BFQ) among young adults in Canada. METHODS: A cross-sectional relative validation study was conducted among young adults aged 16-30 years (n = 50). Participants completed a 17-item BFQ, a 7-day food record (7dFR), and a single-item measure of sugary drink intake. Pearson correlations and paired t-tests were used to evaluate correlation and agreement between the measures for 17 individual beverage categories, total drink consumption, total alcoholic beverage consumption, and two definitions of drinks with excess sugars. Cognitive interviews were conducted to examine participant interpretation and comprehensiveness of the BFQ. RESULTS: Estimates of beverage intake based on the BFQ and the 7dFR were highly correlated, specifically for the total number and volume of beverages consumed, total alcoholic beverage consumption, sugary drink intake, and each of the 17 beverage categories with 3 exceptions: coffee or tea with sugar or cream, specialty coffees, and hard alcohol with caloric mix. Paired t-tests between the BFQ and the 7dFR indicated that the average reported volume was significantly different only for sweetened fruit drinks. The single-item measure of sugary beverage intake was not significantly correlated with the 7dFR. Cognitive interviewing demonstrated high comprehension levels, and confirmed the appropriateness of the BFQ beverage categories and sizes. CONCLUSIONS: Overall, the results suggest that the BFQ performed well relative to a 7dFR and had high usability among this study population, indicating its promise for collecting population-level data on beverage intake, including sugar-sweetened beverages, which are known indicators of diet and health.

Assessing the relative validity of a new, web-based, self-administered 24 h dietary recall in a French-Canadian population.

OBJECTIVE: To assess the relative validity of a new, web-based, self-administered 24 h dietary recall, the R24W, for assessment of energy and nutrient intakes among French Canadians. DESIGN: Each participant completed a 3d food record (FR) and the R24W on three occasions over a 4-week period. Intakes of energy and of twenty-four selected nutrients assessed by both methods were compared. SETTING: Québec City metropolitan area. SUBJECTS: Fifty-seven women and fifty men (mean (sd) age: 47·2 (13·3) years). RESULTS: Equivalent proportions of under-reporters were found with the R24W (15·0%) and the FR (23·4%). Mean (sd) energy intake from the R24W was 7·2% higher than that from the FR (10 857 (3184) kJ/d (2595 (761) kcal/d) v. 10 075 (2971) kJ/d (2408 (710) kcal/d); P<0·01). Significant differences in mean nutrient intakes between the R24W and the FR ranged from -54·8% (i.e. lower value with R24W) for niacin to +40·0% (i.e. higher value with R24W) for alcohol. Sex- and energy-adjusted deattenuated correlations between the two methods were significant for all nutrients except Zn (range: 0·35-0·72; P<0·01). Cross-classification demonstrated that 40·0% of participants were classified in the same quartile with both methods, while 40·0% were classified in the adjacent quartile and only 3·6% were grossly misclassified (1st v. 4th quartile). Analysis of Bland-Altman plots revealed proportional bias between the two assessment methods for 8/24 nutrients. CONCLUSIONS: These data suggest that the R24W presents an acceptable relative validity as compared with the FR for estimating usual dietary intakes in a cohort of French Canadians.

Stability and relative validity of the Neuromuscular Disease Impact Profile (NMDIP).

BACKGROUND: The aim of this study was to examine the stability and relative validity (RV) of the Neuromuscular Disease Impact Profile (NMDIP) using criterion-related groups. In a previous study the NMDIP-scales showed good internal consistency, convergent and discriminant validity. Known-groups analysis showed that the NMDIP discriminates between categories of extent of limitations. METHODS: A cross-sectional postal survey study was performed on patients diagnosed with a NMD and registered at the Department of Neurology, University Medical Center Groningen, the Netherlands. Participants were asked to complete the preliminary NMDIP, the Medical Outcome study Short Form Questionnaire (SF-36), the World Health Organization Quality Of Life-abbreviation version (WHOQOL-bref), and two generic domain specific measures: the Groningen Activity Restriction Scale (GARS) and the Impact on Participation and Autonomy Questionnaire (IPAQ). The variables 'Extent of Limitations' and 'Quality of Life' were used to create criterion-related groups. Stability over time was tested using the Wilcoxon Signed Rank Test for paired samples and the intraclass correlation coefficients for repeated measures. RV was examined by comparing the ability of NMDIP with generic multidimensional health impact measures, and domain specific measures in discriminating between criterion-related subgroups using the Kruskal-Wallis H-test. RESULTS: Response rate was 70% (n = 702). The NMDIP-scales showed sufficient stability over time, and satisfactory or strong RV. In general, the NMDIP scales performed as well as or better than the concurrent measurement instruments. CONCLUSIONS: The NMDIP proved to be a valid and reliable disease-targeted measure with a broad scope on physical, psychological and social functioning.

Reproducibility and relative validity of a FFQ to estimate the intake of fatty acids.

We investigated the validity and reproducibility of the FFQ used in the Dutch European Investigation of Cancer and Nutrition cohort, in order to rank subjects according to intakes of fatty acid classes and individual fatty acids. In total, 121 men and women (23-72 years) filled out three FFQ at 6-month intervals between 1991 and 1992. As a reference method, they filled out twelve monthly 24-h dietary recalls (24HDR) during the same year. Intra-class correlation coefficients for the FFQ showed moderate to good reproducibility across all fatty acids (classes and individual) in men (0·56-0·81) and women (0·57-0·83). In men, Spearman's correlation coefficients (r s) for the FFQ compared with the 24HDR indicated moderate to good relative validity (r s=0·45-0·71) for all fatty acids, except for arachidonic acid and marine PUFA (r s<0·40). In women, relative validity was moderate to good for MUFA and trans-fatty acids (TFA) and the majority of SFA (r s=0·40-0·66), was fair for the short-chain SFA and lauric acid (r s=0·30-0·33) and was fair to moderate for PUFA (r s=0·22-0·47). Bland-Altman plots showed good agreement between the FFQ and 24HDR, and proportional bias for fatty acids with very low intakes. In conclusion, the FFQ showed good reproducibility for subject ranking based on intakes of fatty acids (classes and individual). The relative validity measures indicated that the FFQ is an adequate tool to rank subjects according to intakes of high-abundant fatty acids, but less for low-abundant fatty acids.

Relative validity and reproducibility of a parent-administered semi-quantitative FFQ for assessing food intake in Danish children aged 3-9 years.

OBJECTIVE: To assess the relative validity and reproducibility of the semi-quantitative FFQ (SFFQ) applied in the evaluation of a community intervention study, SoL-Bornholm, for estimating food intakes. DESIGN: The reference measure was a 4 d estimated food record. The SFFQ was completed two times separated by a 1-month period in order to test reproducibility. SETTING: The Capital Region and the Regional Municipality of Bornholm, Denmark. SUBJECTS: A total of fifty-four children aged 3-9 years were enrolled in the study. RESULTS: In terms of validity, the SFFQ generally overestimated intakes compared with the food records, especially for vegetables. For most intakes, the mean difference increased with increasing intake. Gross misclassification was on average higher for energy and nutrients (17%) than for foods (8%). Spearman correlation coefficients were significant for twelve out of fourteen intakes, ranging from 0·29 to 0·63 for foods and from 0·12 to 0·48 for energy and nutrients. Comparing the repeated SFFQ administrations, the intakes of the first SFFQ were slightly higher than those of the second SFFQ. Gross misclassification was low for most intakes; on average 6% for foods and 8% for energy and nutrients. Intra-class correlations were significant for all intakes, ranging from 0·30 to 0·82 for foods and from 0·46 to 0·81 for energy and nutrients. CONCLUSIONS: The results indicate that the SFFQ gives reproducible estimates. The relative validity of the SFFQ was low to moderate for most intakes but comparable to other studies among children.

Relative validity of a semi-quantitative, web-based FFQ used in the 'Snart Forældre' cohort - a Danish study of diet and fertility.

OBJECTIVE: To assess the relative validity of a semi-quantitative, web-based FFQ completed by female pregnancy planners in the Danish 'Snart Forældre' study. DESIGN: We validated a web-based FFQ based on the FFQ used in the Danish National Birth Cohort against a 4 d food diary (FD) and assessed the relative validity of intakes of foods and nutrients. We compared means and medians of intakes, and calculated Pearson correlation coefficients and de-attenuated coefficients to assess agreement between the two methods. We also calculated the proportion correctly classified based on the same or adjacent quintile of intake and the proportion of grossly misclassified (extreme quintiles). SETTING: Participants (n 128) in the 'Snart Forældre' study who had completed the web-based FFQ were invited to participate in the validation study. SUBJECTS: Participants in the 'Snart Forældre' study, in total ninety-seven women aged 20-42 years. RESULTS: Reported intakes of dairy products, vegetables and potatoes were higher in the FFQ compared with the FD, whereas reported intakes of fruit, meat, sugar and beverages were lower in the FFQ than in the FD. Overall the de-attenuated correlation coefficients were acceptable, ranging from 0·33 for energy to 0·93 for vitamin D. The majority of the women were classified in the same or adjacent quintile and few women were misclassified (extreme quintiles). CONCLUSION: The web-based FFQ performs well for ranking women of reproductive age according to high or low intake of foods and nutrients and, thus, provides a solid basis for investigating associations between diet and fertility.

Reliability and relative validity of three physical activity questionnaires in Taizhou population of China: the Taizhou Longitudinal Study.

OBJECTIVE: To examine the test-retest reliabilities and relative validities of the Chinese version of short International Physical Activity Questionnaire (IPAQ-S-C), the Global Physical Activity Questionnaire (GPAQ-C), and the Total Energy Expenditure Questionnaire (TEEQ-C) in a population-based prospective study, the Taizhou Longitudinal Study (TZLS). STUDY DESIGN: A longitudinal comparative study. METHODS: A total of 205 participants (male: 38.54%) aged 30-70 years completed three questionnaires twice (day one and day nine) and physical activity log (PA-log) over seven consecutive days. The test-retest reliabilities were evaluated using intra-class correlation coefficients (ICCs) and the relative validities were estimated by comparing the data from physical activity questionnaires (PAQs) and PA-log. RESULTS: Good reliabilities were observed between the repeated PAQs. The ICCs ranged from 0.51 to 0.80 for IPAQ-C, 0.67 to 0.85 for GPAQ-C, and 0.74 to 0.94 for TEEQ-C, respectively. Energy expenditure of most PA domains estimated by the three PAQs correlated moderately with the results recorded by PA-log except the walking domain of IPAQ-S-C. The partial correlation coefficients between the PAQs and PA-log ranged from 0.44 to 0.58 for IPAQ-S-C, 0.26 to 0.52 for GPAQ-C, and 0.41 to 0.72 for TEEQ-C, respectively. Bland-Altman plots showed acceptable agreement between the three PAQs and PA-log. CONCLUSION: The three PAQs, especially TEEQ-C, were relatively reliable and valid for assessment of physical activity and could be used in TZLS.