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Background The association between cocaine- and amphetamine-regulated transcript prepropeptide gene (CARTPT) and obesity-related outcomes has shown in the epidemiological studies. Nevertheless, there is lack of data regarding the CARTPT gene–diet interactions in terms of antioxidant potential of diet. So, this study aimed to test CARTPT gene–dietary non-enzymatic antioxidant capacity (NEAC) interactions on cardio-metabolic risk factors in obese individuals. Methods and material The present cross-sectional study was carried out among 288 apparently healthy obese adults within age range of 20–50 years. Antioxidant capacity of diet was estimated by calculating the oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), total radical-trapping antioxidant parameter (TRAP) and Trolox equivalent antioxidant capacity (TEAC) using a semiquantitative food frequency questionnaire (FFQ). Genotyping for CARTPT rs2239670 polymorphism was conducted by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) method. Results A significant interaction was revealed between CARTPT rs2239670 and dietary ORAC on BMI (PInteraction = 0.048) and fat mass percent (FM%) (PInteraction = 0.008); in A allele carriers, higher adherence to the dietary ORAC was related to lower level of BMI and FM%. And, the significant interactions were observed between FRAP index and rs2239670 in relation to HOMA (PInteraction = 0.049) and QUICKI (PInteraction = 0.048). Moreover, there were significant interactions of rs2239670 with TRAP (PInteraction = 0.029) and TEAC (PInteraction = 0.034) on the serum glucose level; individuals with AG genotype were more respondent to higher intake of TRAP. Conclusion The present study indicated that the relationships between CARTPT rs2239670 and obesity and its-related metabolic parameters depend on adherence to the dietary NEAC. Large prospective studies are needed to confirm our findings.

Background In China, many people are regarded suitable for participating in regular physical examination for diagnosis and prevention of diseases. Some simplified food frequency questionnaires have been designed and used; however, the accuracy of the questionnaire is absent. This study aimed to examine the reliability and validity of simplified food frequency questionnaire (SFFQ) used among adults undergoing physical examination in southwest region of China. Methods This was a cross-sectional study conducted among physical health examination adults in the Southwest region of China. A total of 239 participants aged 20–65 were included from February 2019 to June 2019. The performance of SFFQ was evaluated by means of a three-day 24-h dietary record (3R24). The relative validity and agreement was assessed by Pearson’s correlation and intra-class correlation coefficients (ICC), respectively. Results The median energy-adjusted ICC of food groups between SFFQ2 and SFFQ1 was 0.59 (range: 0.49–0.73) and the ICC of nutrients was 0.47(range: 0.39–0.76). The Pearson correlation showed a valid comparisons between SFFQ1 and 3R24, ranging from -0.086 to 0.93 for food and 0.21 to 0.71 for nutrition, respectively. The energy-adjustment slightly increased the correlation coefficients. Conclusions The reliability and validity of SFFQ was acceptable, and it could be an appropriate dietary assessment tool for the future epidemiological studies conducted among physical health examination adults of southwest China. Trial registration CHiCTR, ChiCTR1900020934, Registered 22 January 2019, https://www.chictr.org.cn/edit.aspx?pid=35414&htm=4.

PURPOSE: Excessive consumption of free sugar increases the risk for non-communicable diseases where a proper assessment of this intake is necessary to correctly estimate its association with certain diseases. Urinary sugars have been suggested as objective biomarkers for total and free sugar intake in adults but less is known about this marker in children and adolescents. Therefore, the aim of this exploratory study is to evaluate the relative validity of self-reported intake using urinary sugars in children and adolescents. METHODS: The study was conducted in a convenience subsample of 228 participants aged 5–18 years of the I.Family study that investigates the determinants of food choices, lifestyle and health in European families. Total, free and intrinsic sugar intake (g/day) and sugar density (g/1000 kcal) were assessed using 24-h dietary recalls (24HDRs). Urinary sucrose (USUC) and urinary fructose (UFRU) were measured in morning urine samples and corrected for creatinine excretion (USUC/Cr, UFRU/Cr). Correlation coefficients, the method of triads and linear regression models were used to investigate the relationship between intake of different types of sugar and urinary sugars. RESULTS: The correlation between usual sugar density calculated from multiple 24HDRs and the sum of USUC/Cr and UFRU/Cr (USUC/Cr + UFRU/Cr) was 0.38 (p

Background The importance of diet and nutrition during preconception age is a window of opportunity to promote future parental and transgenerational health. As a sub-study to a large Norwegian study, ‘Diet today – health of tomorrow’, a food-frequency questionnaire (FFQ) was developed to assess diet during the preconception phase in young adults aged 20 – 30 years and in this paper we report the reproducibility and relative validity of this questionnaire. Methods The FFQ was developed from an existing FFQ validated in adolescents. Participants were recruited on social media and at a university. Reproducibility was assessed by comparing the test and retest of the FFQ. Relative validity was assessed by comparing intake measured by the FFQ with a 7-day weighed food record. Energy, nutrients and food intake were used to assess the reproducibility and relative validity of the FFQ. The study applied the Spearman’s rank correlation coefficient, percentage of agreement and Cohen’s Kappa to assess reproducibility and validity. Results There were 32 participants recruited to the study, of which 21 participants completed both the test-retest reproducibility and the relative validation. The test-retest reproducibility had a median correlation coefficient of 0.85 for energy and nutrients, a median Spearman’s rank correlation coefficient of 0.75 and a median Cohen’s Kappa of 0.51 for food groups. The relative validity of the FFQ had a median correlation coefficient of 0.59 for energy and nutrients, a median Spearman’s rank correlation coefficient of 0.54 and a median Cohen’s Kappa of 0.28 for food groups. Conclusion This newly developed FFQ for preconception diet in young adults had a satisfactory test-retest reproducibility and fair relative validity.

Background The use of valid dietary assessment methods is crucial to analyse adherence to dietary recommendations among pregnant women. This study aims to assess the relative validity of a self-administered Web-based 24-h dietary recall, the R24W, against a pen-paper 3-day food record (FR) among pregnant women. Methods Sixty (60) pregnant women recruited at 9.3 ± 0.7 weeks of pregnancy in Quebec City completed, at each trimester, 3 R24W and a 3-day FR. Mean energy and nutrient intakes reported by both tools were compared using paired Student T-Tests. Pearson correlations were used to analyze the association between both methods. Agreement between the two methods was evaluated using cross-classification analyses, weighted kappa coefficients and Bland-Altman analyses. Results Pearson correlation coefficients were all significant, except for vitamin B12 (r = 0.03; p = 0.83) and ranged from 0.27 to 0.76 (p

Background: With increased focus on dietary intake among youth and risk of diseases later in life, it is of importance, prior to assessing diet-disease relationships, to examine the validity of the dietary assessment tool. This study’s objective was to evaluate the relative validity of a self-administered web-based FFQ among Danish children aged 12 to 15 years. Methods: From a nested sub-cohort within the Danish National Birth Cohort, 124 adolescents participated. Four weeks after completion of the FFQ, adolescents were invited to complete three telephone-based 24HRs; administered 4 weeks apart. Mean or median intakes of nutrients and food groups estimated from the FFQ were compared with the mean of 3x24HRs. To assess the level of ranking we calculated the proportion of correctly classified into the same quartile, and the proportion of misclassified (into the opposite quartile). Spearman’s correlation coefficients and de-attenuated coefficients were calculated to assess agreement between the FFQ and 24HRs. Results: The mean percentage of all food groups, for adolescents classified into the same and opposite quartile was 35 and 7.5%, respectively. Mean Spearman’s correlation was 0.28 for food groups and 0.35 for nutrients, respectively. Adjustment for energy and within-person variation in the 24HRs had little effect on the magnitude of the correlations for food groups and nutrients. We found overestimation by the FFQ compared with the 24HRs for fish, fruits, vegetables, oils and dressing and underestimation by the FFQ for meat/poultry and sweets. Median intake of beverages, dairy, bread, cereals, the mean total energy and carbohydrate intake did not differ significantly between the two methods. Conclusion: The relative validity of the FFQ compared with the 3x24HRs showed that the ranking ability differed across food groups and nutrients with best ranking for estimated intake of dairy, fruits, and oils and dressing. Larger variation was observed for fish, sweets and vegetables. For nutrients, the ranking ability was acceptable for fatty acids and iron. When evaluating estimates from the FFQ among Danish adolescents these findings should be considered., The study was supported by grants from The Danish Research Council 09–067124 (Center for Fetal Programming), 09–075611; and the Intramural Research Program of The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract # HHSN275201000020C). The funding bodies had no role in the design of the study, collection, analysis, interpretation of data or in writing the manuscript.

To determine the relative validity of parent-assessed and self-assessed symptoms of Generalised Anxiety Disorder (GAD) in boys with an Autism Spectrum Disorder (ASD). 140 boys with an Autism Spectrum Disorder (ASD) were assessed for GAD by their parents and by themselves, and gave a sample of cortisol during the afternoon of these assessments. There were significant differences between self-assessments and parents’ assessments for the total GAD score and on four of the eight individual GAD symptoms. Using cortisol concentrations as a validation index, the two key GAD items were most validly assessed via boys’ self-ratings. Key GAD symptoms in boys with an ASD may be best assessed from their self-reports rather than by their parents’ reports. Implications for clinical practice are discussed.

To evaluate the relative validity of the diet history questionnaire (DHQ) used in the Concord Health and Ageing in Men Project (CHAMP) against a four-day weighed food record (4dWFR) as the reference method. Detailed DHQ followed by a 4dWFR were completed between July 2012 and October of 2013. Setting: Burwood, Canada Bay and Strathfield in Sydney, Australia. Fifty six community- dwelling men aged 75 years and over (mean=79 years). DHQ estimates of intakes were generally higher than estimates from 4dWFR. Differences between the two methods were generally less than 20% with the exception of s-carotene (37%). Fixed and proportional biases were only present for retinol, s-carotene, magnesium, phosphorus and percentage of energy from protein; however, 95% limits of agreement were in some cases wide. Pearson correlation coefficient of log-transformed unadjusted values ranged from 0.15 (zinc) to 0.70 (alcohol), and from 0.06 (iron) to 0.63 (thiamin) after energy-adjustment. Spearman’s correlation coefficients ranged from 0.16 (zinc) to 0.80 (alcohol) before energy adjustment, and from 0.15(zinc) to 0.81(alcohol) after energy adjustment. Our findings suggest that the DHQ used in CHAMP to measure the nutritional intake of its participants is appropriate to this age group and provides reasonably similar results to the 4dWFR for the majority of nutrients analysed.

The aim of this systematic review was to identify and describe brief dietary assessment tools suitable for use in clinical practice in the management of obesity, cardiovascular disease and type 2 diabetes. Papers describing development of brief (

Background Due to the large mortality from inactivity-related non-communicable diseases in low- and middle- income countries, accurate assessment of physical activity is important for surveillance, monitoring and understanding of physical (in)activity epidemiology in many of these countries. Research on relative performance of self-report physical activity instruments commonly used for epidemiological research in Africa have rarely been reported. The present study compared estimates of physical activity measured with the International Physical Activity Questionnaire – Short Form (IPAQ-SF) and the Baecke Physical Activity Questionnaire (BPAQ) among urban and rural black South African adults. Methods Self-reported physical activity data using the IPAQ-SF and BPAQ were collected from a representative sample of 910 urban and rural black South African adults (age = 59.2 ± 9.5 years, 69.7 % women) participating in the 2015 wave of the Prospective Urban and Rural Epidemiological (PURE) study in the North West Province of South Africa. Between-method relationships (pearson correlations [r] and intraclass correlation coefficients [ICCs]) and agreements (Bland-Altman mean difference with 95 % limits of agreement and Kappa coefficient [k]) of IPAQ-SF and BPAQ variables were estimated. Sensitivity and specificity of the BPAQ relative to the IPAQ-SF to classify individuals according to the international guidelines for sufficient physical activity were calculated using chi-square statistics. Results Correlations between IPAQ-SF scores and BPAQ indices were small (r = 0.08–0.18; ICCs = 0.09–0.18) for BPAQ leisure and sport indices, moderate-to-large for work index (r = 0.42–0.59; ICCs = 0.40–0.62) and total physical activity index (r = 0.52–0.60; ICCs = 0.36–0.51). Between methods mean difference for total physical activity was large (1.85 unit), and agreement in physical activity classifications was poor to moderate (k = 0.16–0.44). The sensitivity of the BPAQ to identify sufficiently active people from the IPAQ-SF was very good (98 %), but its specificity to correctly classify insufficiently active people was weak (23 %). Conclusion Notable disparities in physical activity estimates between methods suggest that utilization of IPAQ-SF and BPAQ for surveillance and epidemiology studies in Africa should depend on research questions and population to be studied. Future studies with objective measures are needed to confirm the relative validity between the two instruments.

BACKGROUND: Dietary assessment during adolescence is crucial in determining how adolescents’ consumption habits potentially affect current and long-term health. However, assessment methods for adolescents need to be relevant to their emerging technological culture. We developed a web-based food frequency questionnaire (webFFQ) to assess the habitual soy isoflavones and nutrient intake of adolescents. Our purpose was to validate this webFFQ against multiple 1-day photograph-assisted food records (FR). METHODS: Adolescents aged 12–18 years (n = 70) attending middle and high schools completed the webFFQ and provided six 1-day FR. Fifteen participants were excluded due to improbable energy intake. Statistical agreements were determined using Wilcoxon signed-ranks test, Pearson’s bivariate correlations of normalized values with energy-adjustment and correction for attenuation, cross-classification, and Bland-Altman plots. RESULTS: Based on n = 55, the webFFQ had higher intake estimates for all isoflavones and most nutrients compared to the FR. Energy-adjusted and deattenuated correlations were moderately strong for total isoflavones (r = 0.67), daidzein (r = 0.63), genistein (r = 0.64), and glycitein (r = 0.54). They ranged from a high of 0.82 (animal proteins) to a low of 0.11 (vitamin B12) for nutrients. Cross-classification agreement up to within 1 quartile ranged from 99.0 % (vegetable protein) to 61.8 % (vitamin B12) with low gross misclassifications (0.0–12.7 %). Bland-Altman plots for the isoflavones showed consistent overestimation and wide variation but nevertheless good agreement between the two methods. CONCLUSIONS: The webFFQ is relatively valid in ranking adolescents according to their isoflavones and nutrient intake. However, while it significantly overestimates the absolute intake of most nutrients, results are comparable to other food frequency questionnaires developed for adolescents.

Cluster ensemble aims at producing high quality data partitions by combining a set of different partitions produced from the same data. Diversity and quality are claimed to be critical for the selection of the partitions to be combined. To enhance these characteristics, methods can be applied to evaluate and select a subset of the partitions that provide ensemble results similar or better than those based on the full set of partitions. Previous studies have shown that this selection can significantly improve the quality of the final partitions. For such, an appropriate evaluation of the candidate partitions to be combined must be performed. In this work, several methods to evaluate and select partitions are investigated, most of them based on relative clustering validity indexes. These indexes select the partitions with the highest quality to participate in the ensemble. However, each relative index can be more suitable for particular data conformations. Thus, distinct relative indexes are combined to create a final evaluation that tends to be robust to changes in the application scenario, as the majority of the combined indexes may compensate the poor performance of some individual indexes. We also investigate the impact of the diversity among partitions used for the ensemble. A comparative evaluation of results obtained from an extensive collection of experiments involving state-of-the-art methods and statistical tests is presented. Based on the obtained results, a practical design approach is proposed to support cluster ensemble selection. This approach was successfully applied to real public domain data sets.

Background Food frequency questionnaire (FFQ) is a reliable tool to estimate dietary intake in large nutritional epidemiological studies, but there is lack of a current and validated FFQ for use in urban Chinese pregnant women. This study aimed to evaluate the reproducibility and validity of a semi-quantitative FFQ designed to estimate dietary intake among urban pregnant women in a cohort study conducted in central China. Methods In the reproducibility study, a sample of 123 healthy pregnant women completed the first FFQ at 12–13 weeks gestation and the second FFQ 3–4 weeks later. To validate the FFQ, the pregnant women completed three 24-h recalls (24HRs) between the intervals of two FFQs. Results The intraclass correlation coefficients of two administrations of FFQ for foods ranged from 0.23 (nuts) to 0.49 (fruits) and for nutrients from 0.24 (iodine) to 0.58 (selenium) and coefficients were all statistically significant. The unadjusted Pearson correlation coefficients between two methods ranged from 0.28 (beans) to 0.53 (fruits) for foods and from 0.15 (iodine) to 0.59 (protein) for nutrients. Energy-adjusted and de-attenuated correlation coefficients for foods ranged from 0.35 (beans) to 0.56 (fruits) and for nutrients from 0.11 (iodine) to 0.63 (protein), and all correlations being statistically significant except for iodine, sodium and riboflavin. On average, 67.0 % (51.2 %-80.5 %) of women were classified by both methods into the same or adjacent quintiles based on their food intakes, while 68.5 % (56.1 %-77.2 %) of women were classified as such based on nutrient intakes. Extreme misclassifications were very low for both foods (average of 2.0 %) and nutrients (average of 2.2 %). Bland-Altman Plots also showed reasonably acceptable agreement between two methods. Conclusion This FFQ is a reasonably reliable and valid tool for assessing most food and nutrient intakes of urban pregnant women in central China.

Background Measurement of physical activity in epidemiological studies requires tools which are reliable, valid and culturally relevant. We attempted to develop a physical activity questionnaire (PAQ) that would measure physical activity in various domains over a year and which would be valid for use in adults of different age groups with varying levels of activity in urban and rural settings in low and middle income countries like India. The present paper aims to assess the reliability and validity of this new PAQ- termed the Madras Diabetes Research Foundation- Physical Activity Questionnaire (MPAQ). Methods The MPAQ was administered by trained interviewers to 543 individuals of either gender aged 20 years and above from urban and rural areas in 10 states of India from May to August 2011, followed by a repeat administration within a month for assessing reliability. Relative validity was performed against the Global Physical Activity Questionnaire (GPAQ). Construct validity was tested by plotting time spent in sitting and moderate and vigorous physical activity (MVPA) against body-mass index (BMI) and waist circumference. Criterion validity was assessed using the triaxial accelerometer, in a separate subset of 103 individuals. Bland and Altman plots were used to assess the agreement between MPAQ and accelerometer. Results The interclass correlation coefficients (ICC) for total energy expenditure and physical activity levels were 0.82 and 0.73 respectively, between baseline and 1st month. The ICC between GPAQ and the MPAQ was 0.40 overall. The construct validity of the MPAQ showed linear association between sitting and MVPA, and BMI and waist circumference independent of age and gender. The Spearman’s correlation coefficients for sedentary activity, MVPA and overall PA for MPAQ against the accelerometer were 0.48 (95%CI-0.32-0.62), 0.44 (0.27-0.59) and 0.46 (0.29-0.60) respectively. Bland and Altman plots showed good agreement between MPAQ and accelerometer for sedentary behavior and fair agreement for MVPA. Conclusion The MPAQ is an acceptable, reproducible and valid instrument, which captures data from multiple activity domains over the period of a year from adults of both genders and varying ages in various walks of life residing in urban and rural India. Electronic supplementary material The online version of this article (doi:10.1186/s12966-015-0196-2) contains supplementary material, which is available to authorized users.

Improved methods for quantitative self-reports of total physical activity in epidemiological studies are needed. We evaluated randomly selected individuals' ability to integrate their perception of physical activity over time to produce an estimate of the "usual" level, using a novel instrument for self-quantification of energy expenditure. A population-based sample of 418 Swedish men and women, age 20-59, completed a questionnaire containing the new instrument. For validation, three 24 hour recalls by phone served as gold standard. Reproducibility was assessed through administering the instrument another three times. The validation involved 133 subjects and another 160 completed the reproducibility evaluation. Pearson correlation between usual daily energy expenditure measured by the instrument and the mean of the 24 hour recalls was 0.73. After subdividing the self-reported daily energy expenditure and the mean of the 24 hour recalls into quintiles, 83.5% of the participants remained in the same quintile, or one quintile apart. There was a tendency towards overestimation of usual daily physical activity. This was significantly associated with low education. Reproducibility showed an intraclass correlation of 0.55. Although integrated reports of usual daily energy expenditure over longer periods seem to be afflicted with a tendency of overestimation, total energy expenditure can be estimated with reasonable validity and reproducibility using our instrument.

Objective: To develop a food frequency questionnaire for adolescents (AFFQ) and demonstrate its relative validity. Design: The final version of the AFFQ was composed of 76 food items previously identified according to their contribution in nutrients and overall importance within the eating habits of this population group. The validation study, which was undertaken during a 6 month period (June to November 1999), was administered to a sample of 79 who answered at least three 24 h dietary recalls (R24 h) applied at intervals of 45 days and one AFFQ at the end of the study. Applying the paired t-test and calculating Pearson correlation coefficients on nutrient data, differences in the mean of nutrients were obtained. Correlation coefficients between the mean energy-adjusted nutrients computed by the two methods were calculated, and correction was made for within-person variability. Agreement was evaluated by distribution of the adolescents according to quartiles of consumption. Locus: A public school within the metropolitan region of Sao Paulo city. Results: A high variability in the dietary intake of adolescents was observed, with high rates of variability for cholesterol, retinal and vitamin C. The Pearson correlation coefficients, after being adjusted and corrected for variability, ranged from 0.10 to 0.72 among females and from 0.16 and 0.91 among males. The mean correlation coefficient for the entire group was 0.52. Conclusions: These results indicate that the AFFQ provides a potentially reliable scale for categorizing individuals by level of past intake of most nutrients, excluding retinol and iron.

Background: Item response theory (IRT) scoring of health status questionnaires offers many advantages. However, to ensure 'backwards comparability' and to facilitate interpretations of results, we need the ability to express the IRT score in the metrics of the traditional scales. Objectives: To develop procedures to calibrate IRT-based scores on the Headache Impact Test (HIT) into the metrics of the traditional headache scales. To assess the degree to which the calibrated HIT scores agree with the observed traditional scores and lead to the same conclusions in group comparisons. Methods: We used telephone interview data (n = 1016) and Internet data (n = 1103) from general population surveys of recent headache sufferers. Analyses were conducted in four steps: (1) develop IRT models for all items, (2) for each IRT score level, calculate the expected score on each of the traditional scales (calibration), (3) adjust this calibrated score for measurement error in the IRT score, (4) for each of the traditional scales, assess agreement between calibrated HIT scores and observed scores using intraclass correlation (ICC) and evaluate the agreement of mean scores and the relative validity (RV) in discriminating among groups differing in migraine diagnosis, headache severity, and change in impact over time. Results: For the traditional categorical questionnaire items (the Migraine Specific Questionnaire (MSQ) and the Headache Disability Inventory (HDI)) the calibrated HIT agreed with the observed traditional scores: ICC's were between 0.80 and 0.94. In RV analyses the maximum mean difference between the observed and expected scores was 1.7 points on a 0–100 scale for comparisons at one point in time. Analyses of change over time and analyses calibrating scores from the fixed-form HIT-6 to the metric of other questionnaires were also satisfactory although less precise. Analysis of non-standard questionnaire items (e.g. On how many days in the past 3 months did you have a headache, from the HIMQ and the MIDAS) required special IRT models. Agreement was less good: ICC's were between 0.56 and 0.61 and the maximum mean differences were 2.9 (on a 0–270 scale) and 3.8 (on a 0–450 scale) in RV analyses at one point in time. The ability of the calibrated scale scores to discriminate between groups was at least as good as the ability of the observed sum scales and often remarkably better. Conclusion: The theoretical advantage of IRT models in scale calibration is supported by our results. This approach to achieving comparability of new and widely-used scales and accelerating the accumulation of interpretation guidelines based on previous work warrant testing for measures of other generic and disease-specific concepts.

Objective: To evaluate the feasibility of computerized adaptive testing (CAT) and the reliability and validity of CAT-based estimates of headache impact scores in comparison with 'static' surveys. Methods: Responses to the 54-item Headache Impact Test (HIT) were re-analyzed for recent headache sufferers (n = 1016) who completed telephone interviews during the National Survey of Headache Impact (NSHI). Item response theory (IRT) calibrations and the computerized dynamic health assessment (DYNHA®) software were used to simulate CAT assessments by selecting the most informative items for each person and estimating impact scores according to pre-set precision standards (CAT-HIT). Results were compared with IRT estimates based on all items (total-HIT), computerized 6-item dynamic estimates (CAT-HIT-6), and a developmental version of a 'static' 6-item form (HIT-6-D). Analyses focused on: respondent burden (survey length and administration time), score distributions ('ceiling' and 'floor' effects), reliability and standard errors, and clinical validity (diagnosis, level of severity). A random sample (n = 245) was re-assessed to test responsiveness. A second study (n = 1103) compared actual CAT surveys and an improved 'static' HIT-6 among current headache sufferers sampled on the Internet. Respondents completed measures from the first study and the generic SF-8™ Health Survey; some (n = 540) were re-tested on the Internet after 2 weeks. Results: In the first study, simulated CAT-HIT and total-HIT scores were highly correlated (r = 0.92) without 'ceiling' or 'floor' effects and with a substantial reduction (90.8%) in respondent burden. Six of the 54 items accounted for the great majority of item administrations (3603/5028, 77.6%). CAT-HIT reliability estimates were very high (0.975–0.992) in the range where 95% of respondents scored, and relative validity (RV) coefficients were high for diagnosis (RV = 0.87) and severity (RV = 0.89); patient-level classifications were accurate 91.3% for a diagnosis of migraine. For all three criteria of change, CAT-HIT scores were more responsive than all other measures. In the second study, estimates of respondent burden, item usage, reliability and clinical validity were replicated. The test–retest reliability of CAT-HIT was 0.79 and alternate forms coefficients ranged from 0.85 to 0.91. All correlations with the generic SF-8 were negative. Conclusions: CAT-based administrations of headache impact items achieved very large reductions in respondent burden without compromising validity for purposes of patient screening or monitoring changes in headache impact over time. IRT models and CAT-based dynamic health assessments warrant testing among patients with other conditions.

Background: Migraine and other severe headaches can cause suffering and reduce functioning and productivity. Patients are the best source of information about such impact. Objective: To develop a new short form (HIT-6) for assessing the impact of headaches that has broad content coverage but is brief as well as reliable and valid enough to use in screening and monitoring patients in clinical research and practice. Methods: HIT-6 items were selected from an existing item pool of 54 items and from 35 items suggested by clinicians. Items were selected and modified based on content validity, item response theory (IRT) information functions, item internal consistency, distributions of scores, clinical validity, and linguistic analyses. The HIT-6 was evaluated in an Internet-based survey of headache sufferers (n = 1103) who were members of America Online (AOL). After 14 days, 540 participated in a follow-up survey. Results: HIT-6 covers six content categories represented in widely used surveys of headache impact. Internal consistency, alternate forms, and test–retest reliability estimates of HIT-6 were 0.89, 0.90, and 0.80, respectively. Individual patient score confidence intervals (95%) of app. ±5 were observed for 88% of all respondents. In tests of validity in discriminating across diagnostic and headache severity groups, relative validity (RV) coefficients of 0.82 and 1.00 were observed for HIT-6, in comparison with the Total Score. Patient-level classifications based in HIT-6 were accurate 88.7% of the time at the recommended cut-off score for a probability of migraine diagnosis. HIT-6 was responsive to self-reported changes in headache impact. Conclusions: The IRT model estimated for a 'pool' of items from widely used measures of headache impact was useful in constructing an efficient, reliable, and valid 'static' short form (HIT-6) for use in screening and monitoring patient outcomes.

Objective: To assess the relative validity of a semi-quantitative food frequency questionnaire (SQFFQ) against 28 day weighed diet records (WDRs). Subjects and methods: The SQFFQ was administered to 106 (21 male and 85 female) Japanese dietitians in Aichi Prefecture in autumn, 1996 and four-season consecutive 7 day WDRs were carried out during 1996–1997. We evaluated validity of intakes of 15 foods and 31 macro- and micro-nutrients based on the SQFFQ against those according to 28 day WDRs among 79 Japanese female dietitians. Results: Mean daily intakes of selected foods and nutrients determined by the SQFFQ were generally equivalent to those measured by 28 day WDRs. Pearson's de-attenuated correlation coefficients (CCs) with log-transformation and energy-adjustment between intakes of selected foods and nutrients quantified by the SQFFQ and 28 day WDRs (minimum–median–maximum) ranged from 0.17 (beverages)–0.52 to 0.74 (rice), and Spearman's rank CCs with energy-adjustment ranged from 0.28 (confectionery)–0.42 to 0.68 (rice). Respective Pearson's CCs for intakes of nutrients were 0.28 (PUFAs)–0.51 to 0.73 (magnesium), and Spearman's rank CCs ranged from 0.23 (n-3 PUFAs)–0.45 to 0.71 (magnesium). Favorably higher agreement for intakes of foods/nutrients was achieved along with lower disagreement. Conclusions: Satisfactorily higher relative validity was attained in Japanese female dietitians with the SQFFQ. This calibrated questionnaire seems therefore appropriate for administration to Japanese dietitians to clarify associations between diet and health/disease. Sponsorship: A grant-in-aid from the Ministry of Education, Science, Sports and Culture (06454242). European Journal of Clinical Nutrition (2001) 55, 735–742

Objective: To estimate the relative validity of a computerised dietary history instrument (DISHES 98). Settings: Munich and Berlin. Subjects: A total of 148 persons aged 19–59 y recruited from two research centres. Design: A relative validation study. Energy and macronutrient intakes obtained with DISHES 98 were compared to those assessed with 3-day weighed dietary records and with a 24 h dietary recall. Results: Intakes of energy, total, saturated and monounsaturated fat, polysaccharides and alcohol were significantly higher and intake of dietary fibre was significantly lower with the 3-day records than with DISHES 98. For intakes of total, animal and vegetable protein, total carbohydrates, mono- and disaccharides and cholesterol the mean difference between DISHES 98 and the 3-day dietary records was less than 5% of the intake with DISHES 98. Pearson's correlation coefficients between DISHES 98 and 3-day records varied from 0.34 for intake of polyunsaturated fat to 0.69 for intake of disaccharides and from 0.27 for polyunsaturated fat to 0.65 for total carbohydrates between DISHES 98 and the 24 h recall. The proportion of participants classified into the same or adjacent quintile of intake varied between 66.9% for polyunsaturated fat and 90.4% for alcohol comparing DISHES 98 and 3-day records and between 60.2% for polyunsaturated fat and 78.4% for total carbohydrates comparing DISHES 98 and 24 h recalls. Conclusion: The observed differences between DISHES 98 and the other methods are in an acceptable range for assessing dietary intake in epidemiologic studies. European Journal of Clinical Nutrition (2001) 55, 409–417

Objective: To determine the relative validity of an iron food frequency questionnaire (iron FFQ) designed to assess intakes of dietary iron and its absorption modifiers. Design: A computer-administered food frequency questionnaire was designed to estimate intake of total, non-haem, haem and meat iron as well as dietary components which influence iron absorption (vitamin C, phytate, calcium, grammes of meat/fish/poultry, tea and coffee) in women consuming a Western diet. The relative validity of the iron FFQ was assessed by comparing its results with those from weighed diet records collected over 11 days. Setting: Dunedin, New Zealand. Participants: Forty-nine women aged 19–31 y attending the University of Otago. Results: There was good agreement between the iron FFQ and the weighed diet records for median intakes of total iron, non-haem iron, calcium, tea and coffee. For dietary component intakes, correlations between the two methods ranged from 0.39 (for vitamin C) to 0.87 (for coffee) with 0.52 for total iron, and 0.61 for haem iron. In cross-classification with the weighed diet record, the iron FFQ correctly classified between 22% (for vitamin C) and 51% (for phytate) of participants into the same quartile. Actual values for surrogate categories indicated that the questionnaire can clearly differentiate between low and high intakes of all the dietary components assessed. The questionnaire also showed an acceptable level of agreement between repeat administrations (eg a correlation for total iron of 0.65). Conclusions: The iron FFQ is appropriate for assessing group intakes of total iron, and iron absorption modifiers, in population studies to assess the aetiology and treatment of iron deficiency states in adult women consuming a Western diet. Sponsorship: This research was supported (in part) by a grant from the Health Research Council of New Zealand. European Journal of Clinical Nutrition (2000) 54, 592–599

We report three experiments in which we tested asymptotic and dynamic predictions of the Rescorla-Wagner (R-W) model and the asymptotic predictions of Cheng's probabilistic contrast model (PCM) concerning judgments of causality when there are two possible causal candidates. We used a paradigm in which the presence of a causal candidate that is highly correlated with an effect influences judgments of a second, moderately correlated or uncorrelated cause. In Experiment 1, which involved a moderate outcome density, judgments of a moderately positive cause were attenuated when it was paired with either a perfect positive or perfect negative cause. This attenuation was robust over a large set of trials but was greater when the strong predictor was positive. In Experiment 2, in which there was a low overall density of outcomes, judgments of a moderately correlated positive cause were elevated when this cause was paired with a perfect negative causal candidate. This elevation was also quite robust over a large set of trials. In Experiment 3, estimates of the strength of a causal candidate that was uncorrelated with the outcome were reduced when it was paired with a perfect cause. The predictions of three theoretical models of causal judgments are considered. Both the R-W model and Cheng's PCM accounted for some but not all aspects of the data. Pearce's model of stimulus generalization accounts for a greater proportion of the data.

To examine the impact of college researchershave used a variety of measures of learning and fairlycomparable results have been obtained. This studyundertakes a direct comparison of three learningindicators: college grade-point average, student reportedgrowth (Verbal and Quantitative), and GRE scores(Verbal, Quantitative, and Composite). The same set ofindependent variables was regressed onto each dependent measure using a national sample of 2,289students. Substantive interpretations are presented andcomparisons are made for paired regressions usingalternate indicators. This paper provides evidencesuggesting that (1) student-reported cognitive growthsurvey items have a modest relative validity; (2) theattenuation associated with the use of residual gainscores does not invalidate their use; and (3) comparable results are obtained when using the college GPAand standardized test scores. It is concluded that thealternate measures can be used as proxies for moredirect measures of learning.

Customer satisfaction and service quality measures obtained through consumer surveys invariably have skewed distributions. As such, researchers have questioned the appropriateness of the popular approach of using the mean rating to summarize such data. However, no detailed study on this topic has yet been conducted. In two independent studies, the relative validity of the various indexes that can be used to summarize consumer’s service quality ratings (e.g., mean, median, mode, kurtosis, skewness, top/bottom-tail percentiles) are examined. In Study 1, using typical commercial survey data from a fast-food/convenience retail chain, both the mean and top-box percentiles are found to be the best indicators of service quality, based on their correlation with customer-driven business performance measures. In Study 2, the results are further confirmed by an extensive simulation that varies factors such as the shape of the underlying distribution of customer ratings and the strength of the relationship between customer ratings and business performance measures. The article concludes with a discussion of the findings and implications for future research.

Background As there is no population-specific, simple food-based diet index suitable for examination of diet quality in New Zealand (NZ) adolescents, there is a need to develop such a tool. Therefore, this study aimed to develop an adolescent-specific diet quality index based on dietary information sourced from a Food Questionnaire (FQ) and examine its validity relative to a four-day estimated food record (4DFR) obtained from a group of adolescents aged 14 to 18 years. Methods A diet quality index for NZ adolescents (NZDQI-A) was developed based on ‘Adequacy’ and ‘Variety’ of five food groups reflecting the New Zealand Food and Nutrition Guidelines for Healthy Adolescents. The NZDQI-A was scored from zero to 100, with a higher score reflecting a better diet quality. Forty-one adolescents (16 males, 25 females, aged 14–18 years) each completed the FQ and a 4DFR. The test-retest reliability of the FQ-derived NZDQI-A scores over a two-week period and the relative validity of the scores compared to the 4DFR were estimated using Pearson’s correlations. Construct validity was examined by comparing NZDQI-A scores against nutrient intakes obtained from the 4DFR. Results The NZDQI-A derived from the FQ showed good reliability (r = 0.65) and reasonable agreement with 4DFR in ranking participants by scores (r = 0.39). More than half of the participants were classified into the same thirds of scores while 10% were misclassified into the opposite thirds by the two methods. Higher NZDQI-A scores were also associated with lower total fat and saturated fat intakes and higher iron intakes. Conclusions Higher NZDQI-A scores were associated with more desirable fat and iron intakes. The scores derived from either FQ or 4DFR were comparable and reproducible when repeated within two weeks. The NZDQI-A is relatively valid and reliable in ranking diet quality in adolescents at a group level even in a small sample size. Further studies are required to test the predictive validity of this food-based diet index in larger samples.

The roles of deficient acquisition and deficient expression of learned information in the effect of relative stimulus validity were examined using rats in a conditioned lick suppression paradigm. Recovery from the effect without further pairings of the conditioned stimulus (CS) and the unconditioned stimulus (US) would favor an interpretation of the relative validity effect based on a latent CS-US association as distinct from a failure to acquire the CS-US association. As a potential recovery manipulation, “reminder” treatments, consisting of the US alone (Experiment 1) or the CS alone (Experiment 2), were administered following relative validity training. In both cases, subjects for which the CS target was of low relative predictive validity exhibited enhanced responding relative to appropriate controls. Additionally, Experiment 2 showed that the amelioration of the relative validity deficit was stimulus specific. Thus, the results of these experiments support previous suggestions that the performance deficit resulting from low relative stimulus validity is due, at least in part, to a failure to express acquired information (Cole, Barnet, & Miller, 1995a).

We administered the CAGE, the Short MAST, and the AUDIT to 832 clients at drinking driver treatment programs in Southern California. Correlations among the alcohol screening measures ranged from 0.62 (CAGE and AUDIT) to 0.70 (CAGE and Short MAST). As expected, response time for the CAGE was quicker than for the Short MAST and the AUDIT, but the internal consistency reliability of the CAGE was the lowest and the standard error of measurement largest. Moreover, greater support was found for the relative validity of the Short MAST and AUDIT than the CAGE. The CAGE provides a substantial amount of information quickly, but more reliable and valid information can be obtained with the short MAST or AUDIT measures, which require an additional 1-2 min to administer.

BackgroundDue to the absence of a current and validated food frequency questionnaire (FFQ) for use in New Zealand adolescents, there is a need to develop one as a cost-effective way to assess adolescents’ food patterns. This study aims to examine the test-retest reliability and relative validity of the New Zealand Adolescent FFQ (NZAFFQ) to assess food group intake in adolescents aged 14 to 18 years.MethodsA non-quantitative (without portion size), 72-item FFQ was developed and pretested. Fifty-two participants (aged 14.9 ± 0.8 years) completed the NZAFFQ twice within a two-week period for test-retest reliability. Forty-one participants (aged 15.1 ± 0.9 years) completed a four-day estimated food record (4DFR) in addition to the FFQs to enable assessment of validity. Spearman’s correlations and cross-classification analyses were used to examine relative validity while intra-class correlations were additionally used for test-retest reliability.ResultsWeekly intakes were estimated for each food item and aggregated into 34 food groups. The median Spearman’s correlation coefficient (SCC) between FFQ administrations was 0.71. SCCs ranged from 0.46 forfruit juice or cordialto 0.87 fornon-standard milk. The median intra-class correlation coefficient (ICC) between FFQ administrations was 0.69. The median SCC between food groups from the FFQ and the 4DFR was 0.40 with the highest SCC seen forstandard milk(0.70). The exact agreement between the methods in ranking participants into thirds was highest formeat alternatives(78%), but lowest forred or yellow vegetablesandpotatoes(27%). The mean percent of participants misclassified into extreme thirds for food group intake was 12%.ConclusionsDespite a small sample size, the NZAFFQ exhibited good to excellent short-term test-retest reliability and reasonable validity in ranking the majority of the food group intakes among adolescents aged 14 to 18 years. The comparability of the validity to that in the current literature suggests that the NZAFFQ may be used among adolescent New Zealanders to identify dietary patterns and rank them according to food group intake.

Background Validation of a food frequency questionnaire (FFQ) is important as incorrect information may lead to biased associations. Therefore the relative validity of an FFQ developed for use in the German Health Examination Survey for Adults 2008-2011 (DEGS) was examined. Methods Cross-sectional comparisons of food consumption data from the FFQ and from two 24-hour recalls were made in a sample of 161 participants (aged 18 to 80 years) of an ongoing nationwide survey, the German National Nutrition Monitoring (NEMONIT). The data collection took place from November 2008 to April 2009. Results Spearman rank correlations between the FFQ and the 24-hour dietary recalls ranged from 0.15 for pizza to 0.80 for tea, with two third of the correlation coefficients exceeding 0.30. All correlation coefficients were statistically significant except those for pizza and cooked vegetables. The proportion of participants classified into the same or adjacent quartile of intake assessed by both methods varied between 68% for cooked vegetables and 94% for coffee. There were no statistically significant differences in food consumption estimates between both methods for 38% of the food groups. For the other food groups, the estimates of food consumption by the FFQ were not generally higher or lower than estimates from the 24-hour dietary recalls. Conclusions The FFQ appears to be reasonably valid in the assessment of food consumption of German adults. For some food groups, such as raw and cooked vegetables, relative risks estimates should be interpreted with caution because of the poor ranking agreement.

The Child Perceptions Questionnaire for children aged 11 to 14 years (CPQ11–14) is a 37-item measure of oral-health-related quality of life (OHRQoL) encompassing four domains: oral symptoms, functional limitations, emotional and social well-being. To facilitate its use in clinical settings and population-based health surveys, it was shortened to 16 and 8 items. Item impact and stepwise regression methods were used to produce each version. This paper describes the developmental process, compares the discriminative properties of the resulting four short-forms and evaluates their precision relative to the original CPQ11–14. The item impact method used data from the CPQ11–14 item reduction study to select the questions with the highest impact scores in each domain. The regression method, where the dependent variable was the overall CPQ11–14 score and the independent variables its individual questions, was applied to the data collected in the validity study for the CPQ11–14. The measurement properties (i.e. criterion validity, construct validity, internal consistency reliability and test-retest reliability) of all 4 short-forms were evaluated using the data from the validity and reliability studies for the CPQ11–14. All short forms detected substantial variability in children's OHRQoL. The mean scores on the two 16-item questionnaires were almost identical, while on the two 8-item questionnaires they differed by only one score point. The mean scores standardized to 0–100 were higher on the short forms than the original CPQ11–14 (p < 0.001). There were strong significant correlations between all short-form scores and CPQ11–14 scores (0.87–0.98; p < 0.001). Hypotheses concerning construct validity were confirmed: the short-forms' scores were highest in the oro-facial, lower in the orthodontic and lowest in the paediatric dentistry group; all short-form questionnaires were positively correlated with the ratings of oral health and overall well-being, with the correlation coefficient being higher for the latter. The relative validity coefficients were 0.85 to 1.18. Cronbach's alpha and intraclass correlation coefficients ranged 0.71–0.83 and 0.71–0.77, respectively. All short forms demonstrated excellent criterion validity and good construct validity. The reliability coefficients exceeded standards for group-level comparisons. However, these are preliminary findings based on the convenience sampling and further testing in replicated studies involving clinical and general samples of children in various settings is necessary to establish measurement sensitivity and discriminative properties of these questionnaires.

1. The relative validity of C14-labeled fat and I131-labeled fat in measuring fat absorption was checked in subjects with Neomycin-induced mal-absorption syndrome.

A comparison is made between the scales constructed by the Method of Paired Comparison, Rank Order, and the Method of Successive Intervals. Application of the three psychophysical methods to handwriting specimens and to nationality preferences results in mutually linear scales. Choice of scaling methods becomes, then, a matter of practical convenience rather than of relative validity.

Rats of the Maudsley Reactive and Nonreactive strains were used in two light reinforcement experiments in a Skinner Box with two levers. Different response contingencies were compared in order to test the relative validity of the “stimulus change” and “preference” theories. The results did not support the preference theory, but are consistent with the stimulus change theory.

On M. Mercadier's Test of the Relative Validity of the Electrostatic and Electromagnetic Systems of Dimensions

A SERIES of papers, by M. Mercadier, on the dimensions of physical quantities, has recently been appearing in the Comptes Rendus. They are summarised and extended in the Journal de Physique (July, 1893, p. 289).