Energy-adjusted Pearson Correlation Coefficients Research Articles

Development and Validation of a Food Frequency Questionnaire for Evaluating the Nutritional Status of Patients with Cancer.

Patients with cancer need to maintain proper nutritional status to overcome cancer, alleviate the side effects of chemotherapy, and prevent a recurrence. As such, it is necessary to manage nutritional status. This study aimed to develop a dish-based semi-quantitative food frequency questionnaire (FFQ) to evaluate the nutritional status of patients with cancer and assess the validity of the FFQ. A total of 109 dish items were selected through contribution and variability analyses using the 2016-2018 Korea National Health and Nutrition Examination Survey data. The FFQ was validated against the average 3-day dietary records of 100 patients with cancer. Pearson correlation coefficients and quartile agreements between FFQ and 3-day dietary records were calculated for intake of energy, macronutrients, and micronutrients. Age and energy-adjusted Pearson correlation coefficients ranged from 0.20 (iron) to 0.54 (potassium). The percentage of participants who were classified into the same or adjacent quartile between the FFQ and the 3-day dietary record ranged from 68% (protein) to 81% (energy, dietary fiber). The results suggest that the FFQ is an appropriate tool for assessing nutritional status in Korean cancer patients.

Reproducibility and Validity of a Semi-Quantitative Food Frequency Questionnaire for Assessing Dietary Intake of Vegetarians and Omnivores in Harbin, China.

This study aims to evaluate the reproducibility and validity of a semi-quantitative food frequency questionnaire (SQFFQ) developed for vegetarians and omnivores in Harbin, China. Participants (36 vegetarians and 64 omnivores) administered SQFFQ at baseline (SQFFQ1) and six months later (SQFFQ2) to assess the reproducibility. The 24 h recalls (24 HRs) for three consecutive days were completed between the administrations of two SQFFQs to determine the validity. For reproducibility, Pearson correlation coefficients between SQFFQ1 and SQFFQ2 for vegetarians and omnivores were 0.45~0.88 and 0.44~0.84, respectively. For validity, unadjusted Pearson correlation coefficients were 0.46~0.83 with an average of 0.63 and 0.43~0.86 with an average of 0.61, respectively; energy-adjusted Pearson correlation coefficients were 0.43~0.82 with an average of 0.61 and 0.40~0.85 with an average of 0.59, respectively. Majority of the correlation coefficients for food groups and macronutrients decreased or remained unchanged after energy adjustment. Furthermore, all correlations were statistically significant (p < 0.05). Bland–Altman plots also showed reasonably acceptable agreement between the two methods. In conclusion, the SQFFQ developed in this study has reasonably acceptable reproducibility and validity.

Reliability and validity of an FFQ for South American children and adolescents from the SAYCARE study.

The purpose of this study was to analyse the reliability and validity of a semi-quantitative FFQ to assess food group consumption in South American children and adolescents. The SAYCARE (South American Youth/Child cARdiovascular and Environmental) study is an observational, multicentre, feasibility study performed in a sample of 3- to 18-year-old children and adolescents attending private and public schools from six South American countries. Participants answered the FFQ twice with a two-week interval and three 24-h dietary recalls. Intraclass and Spearman's correlations, weighted Cohen's kappa (κw), percentage of agreement and energy-adjusted Pearson's correlation coefficients were calculated. Seven cities in South America (Buenos Aires, Lima, Medelin, Montevideo, Santiago, Sao Paulo and Teresina). A sample of 200 children and 244 adolescents for reliability analyses and 252 children and 244 adolescents for validity analyses were included. Depending on the food group, for children and adolescents, reliability analyses resulted in Spearman's coefficients from 0·47 to 0·73, intraclass correlation coefficients from 0·66 to 0·99, κw coefficients from 0·35 to 0·63, and percentage of agreement between 72·75 and 83·52 %. In the same way, validity analyses resulted in Spearman's coefficients from 0·17 to 0·37, energy-adjusted Pearson's coefficients from 0·17 to 0·61, κw coefficients from 0·09 to 0·24, and percentages of agreement between 45·79 and 67·06 %. The SAYCARE FFQ achieved reasonable reliability and slight-moderate validity for almost all food groups intakes. Accordingly, it can be used for the purpose of ranking the intake of individuals within a population.

Relative Validity of Three Food Frequency Questionnaires for Assessing Dietary Intakes of Guatemalan Schoolchildren.

ObjectiveTo determine the relative validity of three food frequency questionnaires (FFQs) compared with results from 24-hour dietary recalls for measuring dietary intakes in Guatemalan schoolchildren.DesignA cross-sectional study of primary caregivers (mothers or grandmothers) of 6–11 year-old children. Caregivers completed one of three constructed FFQs to measure the child’s dietary consumption in the last week: FFQ1 did not incorporate portion sizes; FFQ2 provided portion sizes; and FFQ3 incorporated pictures of median portion sizes. During the same week, each caregiver also completed three 24-hour dietary recalls. Results from the FFQ were compared with corresponding results from the 24-hour dietary recalls.SettingSanta Catarina Pinula, peri-urban Guatemala City.SubjectsCaregivers (n = 145) of 6–11 year-old children: 46 completed FFQ1, 49 completed FFQ2, and 50 completed FFQ3.ResultsThe mean values for all nutrients obtained from the 24-hour dietary recall were lower than for those obtained from the FFQs, excluding folic acid in FFQ3, cholesterol and zinc in FFQ2, and cholesterol, folic acid, magnesium, potassium, sodium, and zinc in FFQ1. Energy-adjusted Pearson correlation coefficients ranged from 0.07 (protein) to 0.54 (cholesterol) for FFQ1 and from 0.05 to 0.74 for FFQ2 and FFQ3. Agreement by both methods (FFQ and 24-hour dietary recalls) of classifying children into the same or adjacent quartiles of energy-adjusted nutrient consumption ranged from 62.0% for cholesterol to 95.9% for vitamin B12 across all three FFQs.ConclusionsOur FFQs had moderate to good relative validity in measuring energy and nutrient intakes for 6–11 year-old Guatemalan children. More evidence is needed to evaluate their reproducibility and applicability in similar populations.

Two New Meal- and Web-Based Interactive Food Frequency Questionnaires: Validation of Energy and Macronutrient Intake

BackgroundMeal-Q and its shorter version, MiniMeal-Q, are 2 new Web-based food frequency questionnaires. Their meal-based and interactive format was designed to promote ease of use and to minimize answering time, desirable improvements in large epidemiological studies.ObjectiveWe evaluated the validity of energy and macronutrient intake assessed with Meal-Q and MiniMeal-Q as well as the reproducibility of Meal-Q.MethodsHealthy volunteers aged 20-63 years recruited from Stockholm County filled out the 174-item Meal-Q. The questionnaire was compared to 7-day weighed food records (WFR; n=163), for energy and macronutrient intake, and to doubly labeled water (DLW; n=39), for total energy expenditure. In addition, the 126-item MiniMeal-Q was evaluated in a simulated validation using truncated Meal-Q data. We also assessed the answering time and ease of use of both questionnaires.ResultsBland-Altman plots showed a varying bias within the intake range for all validity comparisons. Cross-classification of quartiles placed 70%-86% in the same/adjacent quartile with WFR and 77% with DLW. Deattenuated and energy-adjusted Pearson correlation coefficients with the WFR ranged from r=0.33-0.74 for macronutrients and was r=0.18 for energy. Correlations with DLW were r=0.42 for Meal-Q and r=0.38 for MiniMeal-Q. Intraclass correlations for Meal-Q ranged from r=0.57-0.90. Median answering time was 17 minutes for Meal-Q and 7 minutes for MiniMeal-Q, and participants rated both questionnaires as easy to use.ConclusionsMeal-Q and MiniMeal-Q are easy to use and have short answering times. The ranking agreement is good for most of the nutrients for both questionnaires and Meal-Q shows fair reproducibility.

Validity and reproducibility of the FFQ (FFQW82) for dietary assessment in female adolescents

To assess the validity and reproducibility of a self-administered FFQ with eighty-two food items (FFQW82) for assessing the habitual diet in female adolescents. The validity of the FFQW82 for assessment of nutrient intake was evaluated by comparison with a 7 d weighed food record (7d-FRRI) reported as 'gold standard'. Reproducibility of the FFQW82 was assessed at an interval of 1 month (test-retest method). The first survey (FFQW82 and 7d-FRRI) was conducted in April 2007 and the second FFQW82 survey was conducted in May 2007. Daily consumption of energy from eleven food groups and nine nutrients were calculated from both instruments for breakfast, lunch, dinner and the whole day. Crude and energy-adjusted Pearson correlation coefficients were calculated using log-transformed data. Middle school, Tokyo, Japan. Female adolescents aged 12-13 years. Sixty-three female adolescents completed both surveys. The relative difference between the energy intake calculated by the FFQW82 and the 7d-FRRI for the whole day, breakfast, lunch and dinner was 8 %, 10 %, 15 % and 10 %, respectively. As for validity, the correlation coefficient of total energy intake for the whole day was 0·31. The result for breakfast was relatively higher (0·59) compared with that for lunch (0·40) and dinner (0·32). For macronutrients, the energy-adjusted correlation coefficient ranged from 0·28 (carbohydrates) to 0·53 (protein). Reproducibility of total energy intake was 0·62 and ranged from 0·46 (fat) to 0·69 (carbohydrate) for macronutrients. These results suggest that the FFQW82 has proved to have some potential with regard to reproducibility among our study population.

Validity of Estimated Dietary Eicosapentaenoic Acid and Docosahexaenoic Acid Intakes Determined by Interviewer-Administered Food Frequency Questionnaire Among Older Adults With Mild-to-Moderate Cognitive Impairment or Dementia

Epidemiologic research is increasingly being focused on elderly persons, many of whom exhibit mild-to-moderate cognitive impairment. This presents a challenge for collection and interpretation of self-reported dietary data. There are few reports on the impact of cognitive function and dementia on the validity of self-reported dietary intakes. Using plasma phospholipid fatty acid profiles as a biomarker of intake, the authors assessed the validity of an interviewer-administered food frequency questionnaire (FFQ) to estimate intakes of 2 marine-based omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), among 273 community-dwelling adults aged > or =60 years participating in the Nutrition, Aging, and Memory in Elders Study (Boston, Massachusetts, 2002-2008). Age- and energy-adjusted Pearson correlation coefficients for correlations between dietary intakes and plasma phospholipids were consistent across categories of high and low cognitive function (r = 0.48), based on Mini-Mental State Examination score, and were similar across clinically diagnosed categories of normal functioning (r = 0.49), mild cognitive impairment (r = 0.45), and dementia (r = 0.52). The FFQ ranked 78% of subjects to within 1 quartile of their plasma phospholipid EPA + DHA quartile. This frequency was consistently high across all cognitive categories. With interviewer administration, this FFQ seems to be a valid method of assessing dietary EPA + DHA intake in older adults with mild-to-moderate cognitive impairment.

Relative validity of a short food frequency questionnaire for assessing nutrient intake versus three-day weighed diet records in middle-aged Japanese.

BACKGROUND: Validation studies on brief food frequency questionnaires (FFQs) for measuring consumption of macro- and micro-nutrients for the general populace are not fully executed in Japan.METHODS: Two hundred and two middle-aged Japanese (73 males and 129 females) in Aich Prefecture, Japan completed an FFQ and 3day-weighed diet records (3d-WDRs) in February 2004. We compared intakes of energy and 26 nutrients computed with the FFQ against those with the 3d-WDRs as a reference.RESULTS: Mean daily intakes of selected nutrients determined with the FFQ were generally less than those with 3d-WDRs. The ratios assessed with the FFQ vs. 3d-WDRs (minimum - median - maximum) were distributed from 0.57 - 0.79 - 1.09 for males, and 0.61 - 0.86 - 1.04 for females. De-attenuated, log-transformed and energy-adjusted Pearson’s correlation coefficients between intakes of selected nutrients quantified with both devices were distributed from 0.12 - 0.45 - 0.86 and energy-adjusted Spearman’s rank correlation coefficients were from 0.13 - 0.35 - 0.76, for males. The respective values for females were 0.10 - 0.38 - 0.66, and 0.11 - 0.34 - 0.47. Median percentages for exact agreement, agreement within adjacent categories, and disagreement according to quartile classification of the energy-adjusted nutrient intakes measured with both methods were 33, 74, and 5 for males, and 35, 76, and 7 for females, respectively.CONCLUSION: Satisfactorily high relative validity indices of most nutrient intakes computed with the FFQ were attained against those with the 3d-WDRs. The questionnaire therefore appears applicable for categorizing individuals according to consumption of energy and selected nutrients in dietary studies of middle-aged Japanese.