Validity of dietary patterns derived in nutrition surveys using a priori and a posteriori multivariate statistical methods

Abstract

Aim: To evaluate the validity of dietary patterns derived using both a priori and a posteriori methods.  Method: Five hundred individuals (46 ± 16 years, 40% males) completed a valid 76-food item food frequency questionnaire and a 3-day dairy. The MedDietScore was used to a priori assess the adherence to the Mediterranean diet, while principal components and cluster analysis were used as the a posteriori methods.  Results: Both the a priori and a posteriori methods used led to relatively low-validity dietary patterns. However, the level of validity reached significance in many cases and, also, varied by the type of validation method used (i.e. Bland and Altman, non-parametric criteria, etc.).  Conclusion: The aforementioned findings may suggest that the use of both a priori and a posteriori pattern analysis in nutrition surveys should be made with conscious thought and further research is needed in order to establish robust methodologies to assess the validity of patterns.

Keywords::

• Multivariate analysis
• dietary patterns
• validity
• food frequency questionnaire
• a priori
• a posteriori

Acknowledgements

The authors are particularly grateful to the men and women from the residence of Athens, who participated in and collaborated on this research. They also wish to express gratitude to E Bathrellou, A. Giotopoulou, C. Katsagoni, M. Bonou, N. Vallianou, J. Barbetseas and P. Avgerinos (field investigators from Harokopio University and Polikliniki Hospital) for their substantial assistance in the enrollment of the participants.

Declarations of interest: The authors state that there are no conflicts of interest.