Repeatability of dietary patterns extracted through multivariate statistical methods: a literature review in methodological issues

Abstract

In the last few years, the need for processing large amount of data in nutrition science was dramatically arose. This created the need to apply, primarily, advanced analytical research methods that could enable researchers to handle the large amount of information. Dietary pattern analysis is a commonly used approach to enable and incorporate this phenomenon in nutrition research. This article reviews the most common dietary pattern's assessment statistical methods, evaluating at the same time the up-to-day knowledge regarding the reliability and validity of the retrieved patterns. The review is based on both a-priori (diet scores) and a-posteriori (multivariate statistical analysis) methods. The reports from the existing few studies suggest that the use of both a-priori and a-posteriori pattern analyses in nutrition surveys should be made with consciousness. The suggestion of new statistical techniques for the control of repeatability of dietary patterns is considered essential.

The role of production process and information on quality expectations and perceptions of sparkling wines

“…The Wilcoxon signed-rank test is a non-parametric equivalent of the paired t-test; its use is suggested when normality of differences does not hold, with the null hypothesis that the central point of the distribution of the differences is expected to be zero, or no difference between the two distributions under comparison can be observed. 67 (Indeed, collected WTP and hedonic ratings do not hold to the normality distribution assumption. The latter is not unexpected, since hedonic ratings were measured on a 1 to 9 scale, while WTP distributions are skewed.)…”

“…Formulas employed refer to a conventional ‘differences estimator’, where the difference of a set of measures (liking and WTP) for the Charmat and Champenoise is compared within the same sample by using paired Wilcoxon signed‐rank test. The Wilcoxon signed‐rank test is a non‐parametric equivalent of the paired t ‐test; its use is suggested when normality of differences does not hold, with the null hypothesis that the central point of the distribution of the differences is expected to be zero, or no difference between the two distributions under comparison can be observed . (Indeed, collected WTP and hedonic ratings do not hold to the normality distribution assumption.…”

Dietary Patterns Are Associated with Cardiovascular and Cancer Mortality among Swiss Adults in a Census-Linked Cohort

“…Therefore, supplementary dietary patterns might have been eliminated during the pre-processing with MCA, but these patterns would not be clearly supported by the data and would be difficult to interpret. Finally, we acknowledge that both principal components and clustering methods are partially based on arbitrary analytic decisions (number of dimensions or clusters to retain, for example [ 18 ]) and may show limited stability [ 47 , 48 ] or reproducibility [ 29 , 49 , 50 , 51 ]…”

Diet Quality Is Associated With Mortality in Adults Aged 80 Years and Older: A Prospective Study

“…Therefore, it is necessary to efficiently screen diet quality in older persons who are more likely to be malnourished to improve their health outcomes during the aging process. Dietary pattern and diet quality have been assessed by a priori and a posteriori methods . However, several methodological issues confound dietary assessment in older persons, including but not limited to feasibility, recall biases, efficacy, and cost.…”

“…Dietary pattern and diet quality have been assessed by a priori and a posteriori methods. 24 However, several methodological issues confound dietary assessment in older persons, including but not limited to feasibility, recall biases, efficacy, and cost. One of the strengths of our current study is the use of an effective and validated dietary screening tool, which is less memory-dependent and more time-efficient, to assess older persons' diet quality.…”