Date of Award


Degree Type


Degree Name

Master of Science (MS)


Mathematics and Statistics

First Advisor

Dr. Christopher Corcoran


In this paper, we discuss distinctive features of longitudinal studies, and illustrate two regression-based methods for the analysis of longitudinal data. A study of dietary patterns and cognitive decline (Cache County Memory Study) is used to motivate our discussion and analysis. Cognitive decline is a risk factor for Alzheimer’s disease, the sixth leading cause of all deaths among Americans. The study attempted to identify dietary patterns associated with reduced risk of age-related cognitive decline in elderly populations. Higher levels of adherence to the Dietary Approaches to Stop Hypertension (DASH) and/or Mediterranean diets were found to be associated with increased cognitive function at the beginning of the study. These differences were not strengthened or weakened over time, but were maintained over the 11 year duration of the study. Diets characterized by high intake of whole grains and nuts were also found to be associated with higher baseline cognitive function, but there was no evidence that these diets are associated with increased or decreased rates of decline after baseline.


This work made publicly available electronically on August 30, 2011.