
Electronic Theses and Dissertations
Date
2025
Document Type
Thesis
Degree Name
Master of Science
Department
Public Health
Committee Chair
Meredith Ray
Committee Member
Hongmei Zhang
Committee Member
Patricia Cisarik
Abstract
This study evaluates common approaches to analyzing ocular longitudinal data. These approaches range from univariate multiple linear regression to mixed-effect modeling to bivariate outcome models, and vary in both overall complexity, and the amount of data used for analysis. Through comparisons of relative model precision and accuracy, the study highlights how modeling choices may affect inference in the context of ocular data analysis. Through the use of simulated datasets based on reference data from a previous longitudinal study of myopia, a total of ten modeling approaches are assessed. The data are simulated under four different correlation and effect size scenarios to examine the robustness of modeling approaches and to provide more generalizable results. These simulations consistently show that more complex mixed modeling approaches result in increased model precision, relative to models with only fixed effects. The benefits of three-level mixed models compared to two-level mixed models depend on if the predictor of interest is measured at the level of the subject or the eye. As correlation between outcomes is decreased, either between the left and right eye, or within an eye over time, mixed modeling approaches show further gains in precision. Notably, bivariate outcome modeling does not outperform univariate outcome mixed models in most scenarios. However, if effect sizes are not consistent between the left and right eye, bivariate outcome modeling is able to more accurately detect and estimate these different effect sizes compared to all other evaluated modeling approaches. These results may allow for more efficient analysis of ocular data, and may enable investigators to use fewer resources to reach the same conclusions.
Library Comment
Notes
Open access.
Recommended Citation
Ollinger, Morgan Christopher, "The Impacts of Model Selection on Effect Size Estimation and Precision in Longitudinal Ocular Research: A Simulation Study" (2025). Electronic Theses and Dissertations. 3761.
https://digitalcommons.memphis.edu/etd/3761
Comments
Data is provided by the student.