Method Of Triads Research Articles

Development and validation of a food frequency questionnaire to assess habitual iodine intake among women of childbearing age.

Adequate iodine status is critical for thyroid hormone synthesis, which is essential for foetal brain development. Suboptimal iodine status has been reported in young women across Europe. Although urinary iodine concentration (UIC) is a good indicator of recent exposure, it does not reflect habitual iodine intake. This study aimed to develop and validate an iodine-specific food frequency questionnaire (I-FFQ) to assess habitual intake in Irish women aged 18-50 years. A 47-item interviewer-administered I-FFQ, informed by national food consumption data on Irish women aged 18-35 years, was developed and validated in a study of 100 nonpregnant women using a 4-day weighed food diary (FD) and UIC as the reference methods. Correlation, cross-classification and Bland-Altman analyses were used to assess agreement and bias between the I-FFQ and FD. Validity coefficients were calculated using the method of triads. Median (interquartile range [IQR]) UIC was 82 (49, 139) µg/L. Median (IQR) intakes were 161 (106, 217) and 133 (98, 182) µg/day for the I-FFQ and FD, respectively (p = 0.001). Estimates were moderately correlated (r = 0.434), and the I-FFQ classified 89% of participants into the same or adjacent tertile of intake as the FD. Validity coefficients for the I-FFQ, FD and UIC were 0.542, 0.800 and 0.228, respectively. Though repeatability analyses 10 weeks later (n = 69) showed slight differences in estimates of intake (I-FFQ1: 164 (104, 210) µg/day; I-FFQ2: 132 (67, 237) µg/day), intakes were highly correlated between administrations (r = 0.627, p = 0.001). The I-FFQ provides a reasonable estimate of habitual iodine intake in young women.

Validity of self-reported sleep duration in the Cancer Prevention Study- 3.

We examined the one-year test re-test reliability and validity criterion of survey-assessed sleep duration collected from two separate questions. The Activity Validation Sub Study included 751 participants of the Cancer Prevention Study-3 study to further investigate rest/activity cycles. Sleep duration was collected using three methods: survey, Daysimeter device, and sleep diary. Survey-assessed sleep duration was collected using 2 different questions, each with different response options (categorical and continuous). Selected participants (n = 170) were asked to wear a Daysimeter device for seven consecutive days for two non-consecutive quarters. Participants were excluded from the current study due to incomplete/implausible survey or device data or reported working night shift. We calculated reliability of pre- and post-survey sleep duration for both survey question using Spearman correlation. We used the method of triads to estimate the validity coefficient (VC) between the three sleep duration measurements in the present study and the "true" latent sleep duration measure, and bootstrapping methods to calculate the 95% confidence intervals (95%CI). Of 119 participants included in the study (52.10% male), test-retest correlation showed strong and moderate correlations for sleep duration collected continuously and categorically, respectively. The VC for survey-assessed continuous sleep duration was 0.82 (95%CI 0.71, 0.90) for weekday and 0.68 (95%CI 0.46, 0.83) for weekend. Performance of the VC was slightly weaker for survey-assessed categorical sleep duration (weekday VC = 0.57 95%CI 0.42, 0.71; weekend VC = 0.47 95%CI 0.29, 0.62). The two survey-assessed sleep duration questions used in the AVSS and CPS-3 cohorts are valid approximations of sleep duration.

Development and Validation of Vitamin D- Food Frequency Questionnaire for Moroccan Women of Reproductive Age: Use of the Sun Exposure Score and the Method of Triad’s Model

This cross-sectional study aimed to develop and validate a vitamin D food frequency questionnaire (VitD-FFQ) to assess vitamin D intake in Moroccan women of reproductive age. Using the method of triads, the VitD-FFQ was validated against seven-day dietary records (7d-FR) and 25-hydroxyvitamin D (25(OH)D) as a biomarker of vitamin D status in 152 women (aged 18-45 years). Participants' sun exposure scores (SES) were assessed using a specific questionnaire (SEQ). Predictors of vitamin D status were identified via linear regression models. Several statistical tests were applied to evaluate the criterion validity of the FFQ against two references methods (7d-FR and the biomarker-serum 25(OH)D). Median (Interquartile range) intakes were 7.10 ± 6.95 µg /day and 6.33 ± 5.02 µg/ day, respectively, for VitD-FFQ and 7d-FR. Vitamin D status was mainly determined by SES (R = 0.47) and vitamin D absolute food intakes derived by the VitD-FFQ (R = 0.56), which demonstrated a more significant prediction ability compared to 7d-FR (R = 0.36). An agreement was observed between the VitD-FFQ and 7d-FR (BA index of 3.29%) with no proportional bias (R2 = 0.002, p = 0.54). <10% of participants were incorrectly classified, and weighted kappa statistics showed that VitD-FFQ had an acceptable ranking ability compared to the 7d-FR and the biomarker. The validity coefficient for the VitD-FFQ was high: ρQR = 0.90 (95%CI: 0.89-0.92), and a range from 0.46 to 0.90. Adjustment for the participants' SES and BMI (body mass index) improved the biomarker's validity coefficient (ρRB 0.63 (95% CI 0.39-0.82). Our results indicate that the VitD-FFQ is valid for estimating absolute vitamin D intake in Moroccan women of reproductive age.

The Unfolding Analysis for Symbolic Objects Based on the Example of the External Car Advertisement Evaluation

Aim: Multidimensional unfolding allows representing both columns (e.g. products, services) and rows (e.g. customers) of the preference matrix on the same low-dimensional map (usually it’s a two or three-dimensional map). The main aim of the paper was to propose how to perform unfolding analysis for symbolic objects. Methodology: The paper describes the possible ways of performing unfolding analysis for symbolic interval-valued data. The external unfolding is described in the details and used in the empirical part of the paper. The data (preferences and dissimilarities) were gathered by using the incomplete method of triads. Results: The empirical part presents an application for unfolding symbolic data to evaluate customers’ preferences, where car advertisements are used as the example. The results presented on a two-dimensional perceptual map allowed to discover seven groups of respondents with different preferences; most of them prefer Skoda, Audi, Volkswagen, and Honda advertisements to Toyota and Volvo. Implications and recommendations: The proposed external approach for symbolic data allows to represent objects as rectangles (on two-dimensional map) or cuboids (in the case of three dimensions). The respondents are represented as points. Further work should focus on creating an algorithm that allows for the presentation of both symbolic objects and preferences expressed by respondents in the form of rectangles or cuboids. Originality/Value: The paper presents an innovative and previously unpresented external unfolding for symbolic data. Besides that it presents how other unfolding approaches could be adapted for symbolic data.

Validity and reliability of a semi-quantitative food frequency questionnaire for assessing dietary vitamin D and calcium intakes in Iranian childbearing age women.

This study aimed to examine the validity and reliability of a semi-quantitative food frequency questionnaire (FFQ) designed to estimate dietary vitamin D and Calcium (Ca) intakes in a sample of Iranian childbearing age women. An 87-item FFQ was developed and 84 healthy childbearing age women completed it. FFQ was validated by comparing its results with the 24-h dietary recall (24-h recall) and serum 25-hydroxyvitamin D (S-25(OH)D) as the references methods. The FFQ was completed for the second time after 4 weeks to assess the reliability of the questionnaire. Data were analyzed using spearman's correlation, cross-classification analysis, Bland-Altman plots, the weighted κ, intraclass classification, and the method of triads. Spearman's correlations between vitamin D and Ca intakes by the FFQ and 24-h recalls and between vitamin D intakes and S-25(OH)D were significant (r: 0.706, r: 0.959, and r: 0.682, respectively, all, P < 0.001). Cross-classification for vitamin D and Ca between two dietary methods and for vitamin D intake of FFQ and S-25(OH)D demonstrated that most of the quartiles were categorized into the same or adjacent quartiles. The Bland Altman plots for these nutrients also demonstrated good agreement. For vitamin D, the validity coefficients (VCs) calculated by the method of the triad for three methods were in the range of 0.808-0.843. The weighted κ for agreement of vitamin D and Ca by FFQ1 and FFQ2 were 0.18 and 0.638, respectively. The findings indicated that the developed FFQ has acceptable validity for estimating vitamin D and Ca. Its reliability for Ca was stronger than vitamin D.

Reproducibility and Validity of a Food Frequency Questionnaire to Measure the Consumption of β-Carotene, β-Cryptoxanthin, Folate, Vitamin D, EPA, and DHA

ObjectivesThe authors assessed the reproducibility and validity of a 166-item semi-quantitative food frequency questionnaire (SFFQ) for a Japanese population, focusing on carotenoids, vitamin D, folate, and fatty acids. Foods for the questionnaire were chosen with a focus on nutrients associated with lifestyle-related diseases.MethodsNutrient intakes were energy-adjusted using the residual method. De-attenuated correlation coefficients between the energy-adjusted nutrients from the SFFQs and DRs were calculated to account for the within-person variation in replicate DRs or plasma biomarkers. Using the method of triads to calculate validity coefficients (VC) and 95% CIs were calculated with both DR's and plasma biomarkers as comparison methods.ResultsThe median of the deattenuated correlations between the second SFFQ and DRs was 0.56 (range, 0.34, 0.74) for 43 energy-adjusted nutrients. The correlations and 95% confidence intervals (CI) for beta-carotene, beta-cryptoxanthin, folate, vitamin D, EPA, and DHA were 0.43 (0.23, 0.60), 0.68 (0.45, 0.82), 0.69 (0.34, 0.87),0.55 (0.37, 0.68), 0.62 (0.37, 0.79), and 0.62 (0.37, 0.79), respectively. The median of intraclass correlation coefficients between the first six and second six days of DR was 0.59, and that between the first and the second SFFQ was 0.49. The VCs and 95% CIs were 0.47 (0.30, 0.73) for β-carotene, 0.59 (0.42, 0.81) for β-cryptoxanthin, 0.85 (0.51, 1.43) for folate, 0.55 (0.36, 0.87) for vitamin D, 0.61 (0.46, 0.82) for EPA, and 0.61 (0.44, 0.86) for DHA.ConclusionsThese findings suggest that a carefully designed food frequency questionnaire can reasonably estimate the intake of important nutrients in a Japanese population.Funding SourcesThe University of Nagasaki President Education Research Grants 2013, 2014, and 2016.

Validity and Relative Validity of Alternative Methods of Assessing Physical Activity in Epidemiologic Studies: Findings From the Men's Lifestyle Validation Study.

In the Men's Lifestyle Validation Study (2011-2013), we examined the validity and relative validity of a physical activity questionnaire (PAQ), a Web-based 24-hour recall (Activities Completed Over Time in 24 Hours (ACT24)), and an accelerometer by multiple comparison methods. Over the course of 1 year, 609 men completed 2 PAQs, two 7-day accelerometer measurements, at least 1 doubly labeled water (DLW) physical activity level (PAL) measurement (n=100 with repeat measurements), and 4 ACT24s; they also measured their resting pulse rate. A subset (n=197) underwent dual-energy x-ray absorptiometry (n=99 with repeated measurements). The method of triads was used to estimate correlations with true activity using DLW PAL, accelerometry, and the PAQ or ACT24 as alternative comparison measures. Estimated correlations of the PAQ with true activity were 0.60 (95% confidence interval (95% CI): 0.52, 0.68) for total activity, 0.69 (95% CI: 0.61, 0.79) for moderate-to-vigorous physical activity (MVPA), and 0.76 (95% CI: 0.62, 0.93) for vigorous activity. Corresponding correlations for total activity were 0.53 (95% CI: 0.45, 0.63) for the average of 4 ACT24s and 0.68 (95% CI: 0.61, 0.75) for accelerometry. Total activity and MVPA measured by PAQ, ACT24, and accelerometry were all significantly correlated with body fat percentage and resting pulse rate, which are physiological indicators of physical activity. Using a combination of comparison methods, we found the PAQ and accelerometry to have moderate validity for assessing physical activity, especially MVPA, in epidemiologic studies.

Validity and Reproducibility of a Semiquantitative Multiple-Choice Food Frequency Questionnaire in Iranian Adults.

Previous multiple-choice food-based food frequency questionnaires (FFQs) were not validated against weighed dietary records (WDRs) in Iran. This study investigated the validity and reproducibility of a multiple-choice semi-quantitative food frequency questionnaire (SQ-FFQ) in adults living in central Iran. Patients with diabetes and their spouses were asked to complete 3 SQ-FFQs by interview, and nine 3-day WDRs, over 9 months. They provided 2 blood samples to assess serum calcium, magnesium, zinc, and vitamin C levels. The Pearson and intraclass correlation coefficients were calculated to assess reproducibility and validity. The degree of misclassification was explored using a contingency table of quartiles which compare the information between third FFQ and WDRs. The method of triads was incorporated to assess validity coefficients between estimated intakes using third FFQ, WDRs, and biochemical markers and assumed true intakes. A total of 180 participants aged 48.9 ± 8.4 years completed the study. Compared to WDRs, FFQs overestimated all nutrient intakes except for iron. The median intraclass correlation between FFQs was 0.56. The median de-attenuated, age, sex, and education adjusted partial correlation coefficients for validity were 0.17 and 0.26 for FFQ1-WDRs and FFQ3-WDRs, respectively. The FFQ3 validity coefficients for vitamin C, calcium, magnesium, and zinc were 0.13, 0.62, 0.89, and 0.66, respectively, using the triads method. The median exact agreement and complete disagreement between FFQ3 and WDRs were 33% and 6%, respectively. The SQ-FFQ seems to be an acceptable tool to assess the long-term dietary intake for future large-scale studies in this population.

Reproducibility, Validity, and Relative Validity of Self-Report Methods for Assessing Physical Activity in Epidemiologic Studies: Findings From the Women’s Lifestyle Validation Study

Among 683 participants in the Women's Lifestyle Validation Study (2010-2012), we evaluated the performance of a self-administered physical activity questionnaire (PAQ) and Web-based 24-hour recalls (Activities Completed Over Time in 24 Hours (ACT24)) using multiple comparison methods. Two PAQs, 4 ACT24s, two 7-day accelerometer measurements, 1 doubly labeled water (DLW) physical activity level (PAL) measure (repeated; n=90), and 4 resting pulse rate measurements were collected over 15 months. The deattenuated correlation between the PAQ and DLW PAL was 0.41 (95% confidence interval (CI): 0.33, 0.49) for total physical activity (PA) and 0.40 (95% CI: 0.31, 0.48) for moderate-to-vigorous PA (MVPA). These correlations were similar when using accelerometry as the comparison method. Single and averaged ACT24 measurements had lower correlations with DLW and accelerometry as comparison methods. The PAQ showed inverse correlations with DLW body fat percentage and resting pulse rate. Using the method of triads, the estimated correlation of the PAQ with true total PA was 0.54 (95% CI: 0.47, 0.62) and that with true MVPA was 0.60 (95% CI: 0.52, 0.69). For averaged ACT24, the estimated correlations were 0.50 (95% CI: 0.43, 0.59) for total PA and 0.47 (95% CI: 0.39, 0.58) for MVPA, and for averaged accelerometry, these estimated correlations were 0.72 (95% CI: 0.64, 0.81) and 0.62 (95% CI: 0.53, 0.71), respectively. The PAQ provided reasonable validity for total PA and MVPA.

An analytical psychometric function for the dual reference duo-trio (DRDT) method

The dual reference duo-trio (DRDT) is an improved balanced-reference duo-trio method, in which two same references are presented in a test but the reference is changed across the tests. The performance of the DRDT has been investigated theoretically based on a simulation-derived psychometric function in a previous paper published in this journal. The DRDT method is more powerful than the conventional duo-trio and the triangle methods. This paper derives an analytical psychometric function for the DRDT. Another form of the psychometric function for the DRDT is also derived based on the Torgerson’s method of triads. Tables and R codes are provided for presentations and calculations of Pc, δ (or d'), and variance of d' (B-value) based on the analytical psychometric function for the method.

Value-meaning formations in mentally ill patients with a religious worldview

IntroductionIt is necessary to consider the religious worldview and spiritual needs of patients with mental illness in the course of psychotherapy and rehabilitation.ObjectivesThe explication of value-meaning formations (VMF) in mental patients with a religious worldview.MethodsG. Kelly’s methodology of personal constructs (Method of Triads, Hinkle’s laddering technique, the assessment repertory grid by F.Fransella&amp;D.Bannister) and statistical analyses were applied.Results1. The structure of the value-meaning formations (VMF) of patients with religious worldview was characterized by its integrity, which is prerequisite for coping. 2. Opposite, patients with absence of religious belief had substantial destruction of integrity and plurality of relationships between VMF. 3. The content of the VMF of mental patients with religious worldview and healthy believers had similarities. 4. In the content of VMF meta-values were: 1. active aspiration to God and the realization of own existence; 2. material well-being in the earthly world; 3. “unselfish” ability to get along without causing harm; 4. feeling of inner confidence.ConclusionsMental disease affects VMF of believers and unbelievers in different way. In unbelievers, the structure of VMF in the course of disease significantly changes. In believers, the disease does not destroy the basis of VMF and allows to keep safe the key elements. The stability of VMF in the believers may be explained by the meaningfulness of life. The concepts of “health” and “disease” are included in the worldview of believers, in the general context of their spiritual, psychic and physical life.DisclosureNo significant relationships.

The Cancer Prevention Study-3 FFQ Is a Reliable and Valid Measure of Nutrient Intakes among Racial/Ethnic Subgroups, Compared with 24-Hour Recalls and Biomarkers

BackgroundValid assessment of dietary intake in diverse populations is important for studies of chronic disease risk in the United States. ObjectivesWe evaluated the reproducibility and validity of a food frequency questionnaire (FFQ) modified for the American Cancer Society’s Cancer Prevention Study-3 (CPS-3) prospective cohort, among a racially/ethnically diverse subgroup. MethodsThe Diet Assessment Substudy included 677 CPS-3 participants (64% women; 61% non-Hispanic white, 24% non-Hispanic black, 15% Hispanic), aged 31–70 y, who completed 2 FFQs 1 y apart (FFQ1, FFQ2), 4–6 telephone-administered 24-h dietary recalls (24HRs), and 2 fasting blood samples and 24-h urine collections ∼6 mo apart in the interim. Spearman rank correlation coefficients (ρ) were used to evaluate FFQ reproducibility and validity compared with 24HRs for 67 nutrient exposures. For 18 of these nutrients, we used the method of triads to calculate validity coefficients (VCs, ρ) from pairwise correlations of FFQ2, 24HRs, and biomarkers. Analyses were stratified by sex, race/ethnicity, education, and BMI. ResultsMean (range) FFQ reproducibility correlations were ρ = 0.65 (0.50–0.91) for men and ρ = 0.63 (0.37–0.89) for women; mean (range) energy-adjusted, deattenuated correlations of FFQ2 with 24HRs were ρ = 0.60 (0.33–0.84) for men and ρ = 0.55 (0.21–0.79) for women. FFQ2 VCs (ρ) among men ranged from 0.42 for β-cryptoxanthin to 0.91 for omega-3 (n–3) fatty acids and, among women, from 0.41 for sodium to 0.79 for total vitamin D. Mean FFQ reproducibility and validity were highest among whites (ρ = 0.68, ρ = 0.58, respectively) and slightly lower among blacks (ρ = 0.57, ρ = 0.49, respectively) and Hispanics (ρ = 0.59, 0.55, respectively). FFQ reproducibility and validity were slightly lower among those with less than a 4-y college degree, and those with a BMI ≥30 kg/m2. ConclusionsReproducibility and validity of the CPS-3 FFQ were comparable with similar studies for most nutrients, among all subgroups. These findings support future dietary analyses in the contemporary CPS-3 cohort and other similar cohorts.

Reproducibility and Validity of a Semiquantitative Food Frequency Questionnaire in Men Assessed by Multiple Methods.

Among 626 participants of the Men's Lifestyle Validation Study (2011-2013), we evaluated the validity and reproducibility of a self-administered 152-item semiquantitative food frequency questionnaire (SFFQ) using two 7-day dietary records (7DDRs), 4 Automated Self-Administered 24-hour dietary recalls (ASA24s), four 24-hour urine samples, 1 doubly labeled water measurement (repeated in 104 participants), and 2 fasting blood samples, collected over 15 months. Compared with 7DDRs, SFFQs underestimated energy intake, macronutrients, and sodium intake but overestimated some micronutrients. The mean of the Spearman correlation coefficients was 0.66 (range, 0.38-0.88) between 46 energy-adjusted nutrients estimated from 7DDRs and the final SFFQ, deattenuated for within-person variation in the 7DDRs. These deattenuated correlations were similar using ASA24s as the comparison. Relative to biomarkers, SFFQs underestimated energy, sodium, and protein intakes, as well as the sodium:potassium ratio. The energy-adjusted correlations between the final SFFQ and the biomarkers were slightly lower than the correlations between the SFFQ and 7DDRs. Using the method of triads to calculate validity coefficients, the median validity coefficient between SFFQ and true intake was 0.65 and 0.69 using 7DDRs and ASA24s, respectively, as the third method. These data indicate that this SFFQ provided reasonably valid estimates for a wide range of nutrients when evaluated by multiple comparison methods.

Estimation of perceptual scales using ordinal embedding.

In this article, we address the problem of measuring and analyzing sensation, the subjective magnitude of one's experience. We do this in the context of the method of triads: The sensation of the stimulus is evaluated via relative judgments of the following form: “Is stimulus more similar to stimulus or to stimulus ?” We propose to use ordinal embedding methods from machine learning to estimate the scaling function from the relative judgments. We review two relevant and well-known methods in psychophysics that are partially applicable in our setting: nonmetric multidimensional scaling (NMDS) and the method of maximum likelihood difference scaling (MLDS). Considering various scaling functions, we perform an extensive set of simulations to demonstrate the performance of the ordinal embedding methods. We show that in contrast to existing approaches, our ordinal embedding approach allows, first, to obtain reasonable scaling functions from comparatively few relative judgments and, second, to estimate multidimensional perceptual scales. In addition to the simulations, we analyze data from two real psychophysics experiments using ordinal embedding methods. Our results show that in the one-dimensional perceptual scale, our ordinal embedding approach works as well as MLDS, while in higher dimensions, only our ordinal embedding methods can produce a desirable scaling function. To make our methods widely accessible, we provide an R-implementation and general rules of thumb on how to use ordinal embedding in the context of psychophysics.

Validation of a Semi-Quantitative Food-Frequency Questionnaire for Dutch Pregnant Women from the General Population Using the Method or Triads

Objective: We aimed to validate a food-frequency questionnaire (FFQ) for Dutch pregnant women, against three 24 h-recalls and blood concentrations of B-vitamins and fatty acids, using the method of triads. Methods: We included 83 pregnant women from the general population of Rotterdam, the Netherlands, at a median gestational age of 15.6 weeks. Participants completed three non-consecutive 24 h-recalls, and subsequently filled out the 293-item FFQ. Participants provided blood samples from which we analyzed serum folate and vitamin B12, as well as red blood cell folate, linoleic acid, and total saturated, monounsaturated, and polyunsaturated fatty acids. Results: Estimated energy intake did not differ between the FFQ and 24 h-recalls. Deattenuated Pearson’s correlation coefficients, between energy-adjusted nutrient intake estimates from the FFQ and the 24 h-recalls, ranged from 0.41 (fat) to 0.88 (fiber) for macronutrients, and were around 0.6 for most micronutrients, except for vitamin E (0.27). Using the triad method, we obtained validity coefficients of 0.86 (95% Confidence Interval (CI) 0.36, 1.00) for serum folate, 0.86 (95% CI 0.18, 1.00) for red blood cell folate, and 1.00 (95% CI 0.42, 1.00) for vitamin B12. Validity coefficients for serum fatty acids ranged from 0.22 to 0.67. Conclusion: This FFQ is a reliable tool for estimating intake of energy, macronutrients, folate and vitamin B12 among women in mid-pregnancy.

Validation of low-calorie sweetener(LCS)-focused food frequency questionnaire for assessment of intakes in a free-living adult population: preliminary results

AbstractBoth obesity and type 2 diabetes mellitus have been associated with excessive free sugar consumption. Increasingly, LCS are used to replace free sugar to reduce the energy density of the diet, whilst maintaining diet palatability. However, while experimental data suggest a beneficial effect of LCS on weight management and glycaemic control, data from free-living populations are contradictory and primarily use reported intakes of low-calorie sweetened beverages as a marker of overall LCS consumption. Therefore, a dietary assessment tool that reliably assesses overall LCS consumption and is applicable in large-scale epidemiological studies is desirable. This study aimed to validate an LCS-focused food frequency questionnaire (FFQ) for assessing habitual dietary intake of the LCS using the method of triads. Healthy adults were recruited at Ulster University, Coleraine (n = 120). A 65-item FFQ and a 4-day food diary (FD) were used to assess dietary intake of LCS with amounts based on maximum permitted levels for foods and beverages as per EU legislation. A novel urinary biomarker approach, developed by this research group, was used to objectively assess consumption of 5 commonly used LCS(1). The method of triads was used to validate the FFQ by evaluating the correlations between the FFQ, FD and the urinary biomarkers (reference method). A total of 110 participants (51 males, 59 females) completed all analyses. Median (IQR) total LCS consumption estimated from the FFQ, FD and urinary biomarker was 116.8 (24.9–303.3) mg/d, 27.8 (0.0–247.3) mg/d and 5.0 (0.6–34.9) mg/d respectively. Moderate correlations were observed between the FD and urinary biomarker (r = 0.471; P &lt; 0.001) and between the FFQ and FD (r = 0.471; P &lt; 0.001). There was a low correlation between the FFQ and urinary biomarker (r = 0.291; P &lt; 0.001). Using the method of triads, the overall validity co-efficient for the FFQ was moderate (0.54). These preliminary results indicate potential for this LCS-focused FFQ as a method of assessing LCS consumption in free-living populations. However, as maximum permitted levels of LCS in foods and beverages were used to estimate LCS consumption from the FFQ and FD, they are likely to significantly overestimate actual LCS intakes as compared to the more reliable biomarker approach. Therefore, the FFQ ability to categorise individuals into low-, medium- and high LCS consumers will be tested. Further analysis is ongoing to assess the completeness of urine collections using PABA analysis and will also focus on individual LCS intake.

Reliability and Validity of the Cancer Prevention Study-3 Physical Activity Survey Items

This study examined the test-retest reliability and criterion validity of light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous (MVPA) physical activity survey items in a subset of participants from a large prospective cohort. Participants included 423 women and 290 men aged 31–72 years in the Cancer Prevention Study-3 (CPS-3). Information on physical activity (PA) was collected using two different surveys: one survey which captures all activity performed during a typical 24-hour period in broad categories (24-hour survey), and a more detailed survey focused primarily on leisure-time PA (LTPA survey). One-year reliability was assessed by computing Spearman correlation coefficients between responses from pre- and post-study periods for both surveys. Validity was assessed by comparing survey-estimated PA with accelerometry, seven-day diaries, and a latent variable representing ‘true’ PA estimated through the method of triads. Reliability was considered acceptable for most items on the LTPA survey (range ρ = 0.45–0.92) and the 24-hour survey (range ρ = 0.37–0.61). LPA validity coefficients were higher for the 24-hour survey, while MPA, VPA, and MVPA coefficients were higher for the LTPA survey. Study results suggest that both CPS-3 PA surveys are suitable for ranking or classifying participants in our population according to overall PA category or intensity-specific activity level.

Preliminary Validation of a Food Frequency Questionnaire to Assess Long-Chain Omega-3 Fatty Acid Intake in Eye Care Practice.

Clinical recommendations relating to dietary omega-3 essential fatty acids (EFAs) should consider an individual’s baseline intake. The time, cost, and practicality constraints of current techniques for quantifying omega-3 levels limit the feasibility of applying these methods in some settings, such as eye care practice. This preliminary validation study, involving 40 adults, sought to assess the validity of a novel questionnaire, the Clinical Omega-3 Dietary Survey (CODS), for rapidly assessing long-chain omega-3 intake. Estimated dietary intakes of long-chain omega-3s from CODS correlated with the validated Dietary Questionnaire for Epidemiology Studies (DQES), Version 3.2, (Cancer Council Victoria, Melbourne, Australia) and quantitative assays from dried blood spot (DBS) testing. The ‘method of triads’ model was used to estimate a validity coefficient (ρ) for the relationship between the CODS and an estimated “true” intake of long-chain omega-3 EFAs. The CODS had high validity for estimating the ρ (95% Confidence Interval [CI]) for total long-chain omega-3 EFAs 0.77 (0.31–0.98), docosahexaenoic acid 0.86 (0.54–0.99) and docosapentaenoic acid 0.72 (0.14–0.97), and it had moderate validity for estimating eicosapentaenoic acid 0.57 (0.21–0.93). The total long-chain omega-3 EFAs estimated using the CODS correlated with the Omega-3 index (r = 0.37, p = 0.018) quantified using the DBS biomarker. The CODS is a novel tool that can be administered rapidly and easily, to estimate long-chain omega-3 sufficiency in clinical settings.

Combining biomarker and self-reported dietary intake data: A review of the state of the art and an exposition of concepts.

Classical approaches to assessing dietary intake are associated with measurement error. In an effort to address inherent measurement error in dietary self-reported data there is increased interest in the use of dietary biomarkers as objective measures of intake. Furthermore, there is a growing consensus of the need to combine dietary biomarker data with self-reported data. A review of state of the art techniques employed when combining biomarker and self-reported data is conducted. Two predominant methods, the calibration method and the method of triads, emerge as relevant techniques used when combining biomarker and self-reported data to account for measurement errors in dietary intake assessment. Both methods crucially assume measurement error independence. To expose and understand the performance of these methods in a range of realistic settings, their underpinning statistical concepts are unified and delineated, and thorough simulation studies are conducted. Results show that violation of the methods' assumptions negatively impacts resulting inference but that this impact is mitigated when the variation of the biomarker around the true intake is small. Thus there is much scope for the further development of biomarkers and models in tandem to achieve the ultimate goal of accurately assessing dietary intake.

Demographic-specific Validity of the Cancer Prevention Study-3 Sedentary Time Survey.

This study examined the 1-yr test-retest reliability and criterion validity of sedentary time survey items in a subset of participants from a large, nationwide prospective cohort. Participants included 423 women and 290 men age 31 to 72 yr in the Cancer Prevention Study-3. Reliability was assessed by computing Spearman correlation coefficients between responses from prestudy and poststudy surveys. Validity was assessed by comparing survey-estimated sedentary time with a latent variable representing true sedentary time estimated from the 7-d diaries, accelerometry, and surveys through the method of triads. Sensitivity analyses were restricted to 566 participants with an average of 14+ h of diary and accelerometer data per day for 7 d per quarter. Reliability estimates for total sitting time were moderate or strong across all demographic strata (Spearman ρ ≥ 0.6), with significant differences by race (P = 0.01). Reliability estimates were strongest for the TV-related sedentary time item (Spearman ρ, 0.74; 95% confidence interval, 0.70-0.77). The overall validity coefficient (VC) for survey-assessed total sedentary time was 0.62 (95% confidence interval, 0.55-0.69), although VC varied by age group and activity level (P < 0.05). However, VC were similar across groups (P < 0.05) when restricting to highly compliant participants in a sensitivity analysis. The Cancer Prevention Study-3 sedentary behavior questionnaire has acceptable reliability and validity for ranking or categorizing participants according to sedentary time. Acceptable reliability and validity estimates persist across various demographic subgroups.