Relative validity and reproducibility of an interviewer administered 14-item FFQ to estimate flavonoid intake among older adults with mild-moderate dementia
Kent, K and Charlton, K, Relative validity and reproducibility of an interviewer administered 14-item FFQ to estimate flavonoid intake among older adults with mild-moderate dementia, Journal of Nutrition in Gerontology and Geriatrics, 36, (2-3) pp. 134-147. ISSN 2155-1197 (2017) [Refereed Article]
There is a large burden on researchers and participants when attempting to accurately measure dietary flavonoid intake using dietary assessment. Minimizing participant and researcher burden when collecting dietary data may improve the validity of the results, especially in older adults with cognitive impairment. A short 14-item food frequency questionnaire (FFQ) to measure flavonoid intake, and flavonoid subclasses (anthocyanins, flavan-3-ols, flavones, flavonols, and flavanones) was developed and assessed for validity and reproducibility against a 24-hour recall. Older adults with mild-moderate dementia (n†=†49) attended two interviews 12 weeks apart. With the assistance of a family carer, a 24-h recall was collected at the first interview, and the flavonoid FFQ was interviewer-administered at both timepoints. Validity and reproducibility was assessed using the Wilcoxon signed-rank sum test, Spearmanís correlation coefficient, Bland-Altman Plots, and Cohenís kappa. Mean flavonoid intake was determined (FFQ1 = 795 Ī 492.7 mg/day, 24-h recall = 515.6 Ī 384.3 mg/day). Tests of validity indicated the FFQ was better at estimating total flavonoid intake than individual flavonoid subclasses compared with the 24-h recall. There was a significant difference in total flavonoid intake estimates between the FFQ and the 24-h recall (Wilcoxon signed-rank sum p†<†0.001; Bland-Altman plots indicated large bias and wide limits of agreement), but they were well correlated (Spearmanís correlation coefficient r = 0.74, p†<†0.001; Cohenís kappa κ = 0.292, p†<†0.001). The FFQ showed good reproducibility, with a small mean percentage difference (12.6%). The Wilcoxon signed-rank sum test showed no significant difference, Spearmanís correlation coefficient indicated excellent reliability (r = 0.75, p†<†0.001), Bland-Altman plots visually showed small, nonsignificant bias and wide limits of agreement, and Cohenís kappa indicated fair agreement (κ = 0.429, p†<†0.001). A 14-item FFQ developed to easily measure flavonoid intake in older adults with dementia demonstrates fair validity against a 24-h recall and good reproducibility.
flavonoid, dementia, food frequency questionnaire, dietary assessment