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Professor of PsychiatryProfessor of
Biostatistics (College of Public Health)
Office: 1-328 Medical Education BuildingIowa City, IA 52242
BA, Psychology, University of CaliforniaMS, Experimental Psychology, California State UniversityPhD, Quantitative Psychology, University of Southern California
My area is applied statistics in medicine and the behavioral sciences. I am specifically interested in statistical models for use in the study of neurodegenerative diseases, especially Huntington disease. My work focuses on the long-term course of neurodegenerative diseases, which involves the application of longitudinal and time-to-event models.
The work I perform is primarily associated with my role as the head statistician for Neurobiological Predictors of Huntington's Disease (PREDICT-HD), funded by the National Institute of Neurological Disorders and Stroke (NINDS). PREDICT-HD is a longitudinal observational study that focuses on identifying the earliest changes associated with disease onset.
I am also a lead biostatistician in the Department of Biostatistics' Data Coordinating Center (DCC) for the Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT). NeuroNEXT is a NINDS-funded infrastructure to facilitate rapid development and implementation of protocols in neurological disorders. The DCC assists in the design and analysis of Phase II clinical trials.
Another interest of mine is open-source (free) software for statistical analysis and report generation. This includes the R software for statistical computing and graphics, the wxMaxima computer algebra system, RStudio for interactive programming, and MiKTeX and Sweave for report writing.
In addition to the professional publications below, I am the co-author (with A. Zieffler and J. Harring) of the textbook “Comparing Groups: Randomization and Bootstrap Methods using R” (New York: Wiley). I am also the author of the textbook “Longitudinal Data Analysis for the Behavioral Sciences using R” (Thousand Oaks, CA: Sage).
Longitudinal Psychiatric Symptoms in Prodromal Huntington's Disease: A Decade of Data..
The American journal of psychiatry.
2016 February 1. 173(2):184-92.
Multivariate clustering of progression profiles reveals different depression patterns in prodromal Huntington disease..
2015 November 1. 29(6):949-60.
Network topology and functional connectivity disturbances precede the onset of Huntington's disease..
Brain : a journal of neurology.
2015 August 1. 138(Pt 8):2332-46.
Multivariate prediction of motor diagnosis in Huntington's disease: 12 years of PREDICT-HD.
Diffusion weighted imaging of prefrontal cortex in prodromal Huntington's disease.
Human Brain Mapping.
Onset of Huntington disease: Can it be purely cognitive?.
et al .
Prediction of manifest Huntington disease with clinical and imaging measures: A 12-year prospective observational study.
The Lancet Neurology.
The early longitudinal course of affective and cognitive symptoms and disorders in de novo patients with Parkinson’s disease.
Journal of Neurology.
Tracking motor impairments in the progression of Huntington's Disease.
Cognitive decline in prodromal Huntington Disease: Implications for clinical trials.
Journal of Neurology, Neurosurgery and Psychiarty.
Date Last Modified: 04/12/2016 -
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