Robust Clustering With Subpopulation-Specific Deviations

Abstract

The National Birth Defects Prevention Study (NBDPS) is a case-control study of birth defects conducted across 10 U.S. states. Researchers are interested in characterizing the etiologic role of maternal diet, collected using a food frequency questionnaire. Because diet is multidimensional, dimension reduction methods such as cluster analysis are often used to summarize dietary patterns. In a large, heterogeneous population, traditional clustering methods, such as latent class analysis, used to estimate dietary patterns can produce a large number of clusters due to a variety of factors, including study size and regional diversity. These factors result in a loss of interpretability of patterns that may differ due to minor consumption changes. Based on adaptation of the local partition process, we propose a new method, robust profile clustering, to handle these data complexities. Here, participants may be clustered at two levels: (1) globally, where women are assigned to an overall population-level cluster via an overfitted finite mixture model, and (2) locally, where regional variations in diet are accommodated via a beta-Bernoulli process dependent on subpopulation differences. We use our method to analyze the NBDPS data, deriving prepregnancy dietary patterns for women in the NBDPS while accounting for regional variability. Supplementary materials for this article, including a standardized description of the materials available for reproducing the work, are available as an online supplement.

Keywords:

• Food frequency questionnaire
• Latent class analysis
• Local partition process
• Nutritional epidemiology

Acknowledgments

We thank Willem van den Boom for assistance in data replication. Finally, we thank Louise Ryan and David Dunson for helpful comments on earlier drafts of this work.

Additional information

Funding

The authors gratefully acknowledge this work was supported in part through cooperative agreements from the Centers for Disease Control and Prevention to the centers participating in the National Birth Defects Prevention Study and by the National Institutes of Health (R01ES020619; R01ES027498; U50CCU422096; 5U01DD001036; PA 96043; PA 02081; FOA DD09-001; NIEHS T32ES007018). Dietary and nutrition information was made possible by the University of North Carolina Epidemiology Core (grant no: DK56350).