Dataset Information

Managing Outliers in Adolescent Food Frequency Questionnaire Data.

ABSTRACT:

Objective

The goal of this study was to explore the impact of 5 decision rules for removing outliers from adolescent food frequency questionnaire (FFQ) data.

Design

This secondary analysis used baseline and 3-month data from a weight loss intervention clinical trial.

Participants

African American adolescents (n = 181) were recruited from outpatient clinics and community health fairs.

Variables measured

Data collected included self-reported FFQ and mediators of weight (food addiction, depressive symptoms, and relative reinforcing value of food), caregiver-reported executive functioning, and objectively measured weight status (percentage overweight).

Analysis

Descriptive statistics examined patterns in study variables at baseline and follow-up. Correlational analyses explored the relationships between FFQ data and key study variables at baseline and follow-up.

Results

Compared with not removing outliers, using decision rules reduced the number of cases and restricted the range of data. The magnitude of baseline FFQ-mediator relationships was attenuated under all decision rules but varied (increasing, decreasing, and reversing direction) at follow-up. Decision rule use increased the magnitude of change in FFQ estimated energy intake and significantly strengthened its relationship with weight change under 2 fixed range decision rules.

Conclusions and implications

Results suggest careful evaluation of outliers and testing and reporting the effects of different outlier decision rules through sensitivity analyses.

SUBMITTER: Lee MS

PROVIDER: S-EPMC7855646 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Publications

Managing Outliers in Adolescent Food Frequency Questionnaire Data.

Lee Morgan S MS Carcone April Idalski AI Ko Linda L Kulik Noel N Ellis Deborah A DA Naar Sylvie S

Journal of nutrition education and behavior 20201001 1

<h4>Objective</h4>The goal of this study was to explore the impact of 5 decision rules for removing outliers from adolescent food frequency questionnaire (FFQ) data.<h4>Design</h4>This secondary analysis used baseline and 3-month data from a weight loss intervention clinical trial.<h4>Participants</h4>African American adolescents (n = 181) were recruited from outpatient clinics and community health fairs.<h4>Variables measured</h4>Data collected included self-reported FFQ and mediators of weight ...[more]

PMID: 33012663

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Project description:Background/objectivesAn adapted version of an online pictorial food frequency questionnaire (FFQ), VioScreen-Allergy, assesses total dietary intake and intake of allergens and foods in the maternal diet index (MDI), linked to offspring allergy. This study assessed intermethod reliability, test-retest reliability, and external validity of the VioScreen-Allergy.MethodsFemales of childbearing age were recruited at Denver Health and Children's Hospital, Colorado, USA, and were asked to complete four 24 h recalls and two VioScreen-Allergy FFQs over the course of a month. All those with at least two 24 h dietary recalls and both VioScreen-Allergy assessments were analyzed. Energy-adjusted and non-adjusted linear mixed models (1) compared MDI scores and intake of nutrients and allergens as measures of intermethod reliability; (2) evaluated VioScreen-Allergy test-retest reliability as differences between repeated measurements; and (3) assessed external validity by modeling associations between VioScreen-Allergy-derived intake of beta-carotene and orange vegetables and Veggie Meter®-assessed skin carotenoids. Bonferroni corrections controlled multiple comparisons within the assessment.ResultsOf 53 participants enrolled, 25 demographically dissimilar participants were included in the analysis. There were no significant differences between 24 h recall and VioScreen-Allergy mean intakes of macronutrients, micronutrients, allergens, or MDI, except for Vitamin C, niacin, and cashew allergen protein. There were no significant differences between repeated measurements of VioScreen-Allergy, either energy-adjusted or unadjusted. Both beta-carotene and orange vegetable servings were significantly associated with Veggie Meter®.ConclusionsAlthough non-significance could have been due to low power, clinical as well as statistical assessments of intermethod reliability, test-retest reliability, and external validity suggest that VioScreen-Allergy has reasonable utility for trials assessing food allergens and MDI in the context of overall intake. The VioScreen questionnaire can also be used in future studies to assess macro- and micronutrient intake. Additional validation studies assessing different portion sizes and foods eaten by infants and young children are currently undergoing.

Dataset Information

Managing Outliers in Adolescent Food Frequency Questionnaire Data.

Objective

Design

Participants

Variables measured

Analysis

Results

Conclusions and implications

Publications

Managing Outliers in Adolescent Food Frequency Questionnaire Data.

Similar Datasets

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