dementia-2016_scientifictracks-abstracts

16 / 46

Notes:
Page 35
Dementia 2016
September 29-October 01, 2016
Volume 6 Issue 5(Suppl) J Alzheimers Dis Parkinsonism 2016
ISSN:2161-0460 JADP, an open access journal
conferenceseries .com
September 29-October 01, 2016 London, UK
5th International Conference on
Alzheimer’s Disease & Dementia
Folefac Atem, J Alzheimers Dis Parkinsonism 2016, 6:5(Suppl)
Imputation and Censored Covariate: Application to Alzheimer Study
Folefac Atem
University of Texas Health Science Center, USA
The association between maternal age of onset of dementia and beta-amyloid deposition (measured by in vivo PET imaging)
in cognitively normal older offspring is of interest. In a regression model for beta-amyloid, special methods are required
due to the random right censoring of the covariate of maternal age of onset of dementia. Prior literature has proposed methods
to address the problem of censoring due to assay limit of detection, but not random censoring. We propose imputation methods
and a survival regression method that do not require parametric assumptions about the distribution of the censored covariate.
Existing imputation methods address missing covariates, but not right censored covariates. In simulation studies, we compare
these methods to the simple, but inefficient complete case analysis, and to thresholding approaches. We apply the methods to
the Alzheimer’s study.
Biography
Folefac Atem, PhD, MS is a Biostatistician. Dr. Atem is an Assistant Professor in the Department of Biostatistics at the University of Texas Health Science Center at
Houston. His office is located at UT Southwestern medical school. He completed his PhD from the University of Pittsburgh in 2010 and Postdoc at Harvard in 2014.