Shared and ethnic background site-specific dietary patterns in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Dietary patterns (DPs) synthesize multiple related dietary components in one or more combined variables. A drawback of DPs is their limited reproducibility across subpopulations, especially adopting a posteriori DPs, derived using standard multivariate methods [e.g., factor analysis (FA)]. Standard approaches assessing reproducibility of FA-based DPs mostly rely on correlation coefficients/agreement measures between pairs of factors and do not consider any statistical model. Multi-study factor analysis builds upon standard FA model to identify DPs shared across all subpopulations and those specific to some subpopulations. Pattern reproducibility is investigated from a different perspective: a shared DP identified within multi-study factor analysis is "reproducible" since it is common to all subpopulations. Bayesian multi-study factor analysis (BMSFA) has been developed to improve DP retention and identification, two critical issues as the number of subpopulations analyzed increases. Using baseline (2008-2011) 24-hour dietary recalls from the Hispanic Community Health Study/Study of Latinos (n=16,415), we applied the BMSFA on 42 common nutrients to identify shared and subpopulation-specific DPs where subpopulations were defined as the cross-classification of ethnic background and study site (EBS). Overall, 4 shared DPs were identified: Plant-based foods, Processed foods, Dairy products, and Seafood. At the subpopulation level, we identified 12 EBS-specific DPs, one for each EBS category, primarily representing variants of foods from animal sources. Different nuances were expressed by subsets of fairly similar EBS-specific DPs, including an Animal vs. vegetable source, an Animal source only, and a Poultry vs. dairy products overarching DPs. Shared DPs from BMSFA were similar to their counterparts from standard FA and frequentist multi-study factor analysis; EBS-specific DPs from BMSFA were better characterized than those from frequentist multi-study factor analysis. In conclusion, the BMSFA successfully captured sources of both dietary homogeneity and heterogeneity in a large well-characterized study of US Hispanics/Latino adults by ethnic background and site.