Sharon Xiangwen Xie, PhD

Office Location607, Blockley Hall
Office Phone215-573-3867
Emailsxie@mail.med.upenn.edu

Faculty Information

CCEB AppointmentSenior Scholar, Biostatistics
Primary Faculty AppointmentAssociate Professor of Biostatistics at HUP, University of Pennsylvania Perelman SOM

Research Statement

Dr. Xie is currently principal investigator of the biostatistics and data management core for two NIH-funded neurodegenerative disease research centers: the Alzheimer's Disease Center and Morris K. Udall Parkinson's Disease Research Center of Excellence. Dr. Xie's current research goals are twofold. First, she continues to develop methods for measurement error problems, survival analysis, and receiver operating characteristic (ROC) analysis in response to methodological problems arising in her collaborative work in the research of neurodegenerative diseases (e.g. Alzheimer's disease & Parkinson's disease), as well as other collaborative research. She has developed new methods to reduce the biases of relative risk estimators in Cox regression models in the presence of covariate measurement error. She has also developed new methods to estimate true exposure/outcome variables using measurements from multiple instruments with systematic biases and non-constant variances. Second, she continues to develop techniques and markers to better understand the progression of neurodegenerative diseases. As a primary example, Dr. Xie and colleagues examined the rate of decline in Alzheimer's disease measured by a dementia severity rating scale (DSRS). She found that the rate of decline was linear using this rating scale. This linearity has significant advantages for clinical trials. Treatment effects in a trial would be seen in the DSRS as a slowing of the linear rate of change during some or all stages of the disease. This is much easier than evaluating estimated treatment effects in a measure that does not change linearly.


Awards and Professional Recognition:

Dr. Xie was the recipient of the 1999 Young Investigator Award of Statistics in Epidemiology Section of the American Statistical Association and the 2005 recipient of the University of Pennsylvania Graduate Program in Biostatistics Teaching Award. She has been an elected standing member of the National Institute of Aging Alzheimer's Disease Center Data Core Steering Committee since 2007 (Chair during July 2008 and July 2009). Dr. Xie is currently a senior editor in Alzheimer's & Dementia.

Courses Taught

BSTA 653 - Survival Analysis

Selected Publications

Xie, S.X., Wang, C.Y., Prentice, R.L. A risk set calibration method for failure time regression by using a covariate reliability sample. Journal of the Royal Statistical Society, Series B 63(4):855-870, 2001.

Wang, C.Y., Xie, S.X., Prentice, R.L. Recalibration based on an approximate relative risk estimator in Cox regression with missing covariates. Statistica Sinica 11:1081-1104, 2001.

Xie, S.X., Liao, D., Chinchilli, V.M. Measurement error reduction using weighted average method for repeated measurements from heterogeneous instruments. Environmetrics 12:785-790, 2001.

Clark, C.M., Xie, S., Chittams, J., Ewbank, D., Peskind, E., Galasko, D., Morris, J.C., McKeel, D.W. Jr., Farlow, M., Weitlauf, S.L., Quinn, J., Kaye, J., Knopman, D., Arai, H., Doody, R.S., DeCarli, C., Leight, S., Lee, V.M.-Y., Trojanowski, J.Q. Cerebrospinal fluid tau and β-amyloid: How well do these biomarkers reflect autopsy confirmed dementia diagnoses? Archives of Neurology 60:1696-1702, 2003.

Karlawish, J.H.T., Casarett, D.J., James, B.D., Xie, S.X., Kim, S.Y.H. The ability of persons with Alzheimer's disease (AD) to make a decision about taking an AD treatment. Neurology 64:1514-1519, 2005.

Brown, G.K., Ten Have, T., Henriques, G.R., Xie, S.X., Hollander, J.E., Beck, A.T. Cognitive therapy for the prevention of suicide attempts: A randomized controlled trial. Journal of the American Medical Association 294(5):563-570, 2005.

Zhang, B., Maiti, A., Shively, S., Lakhani, F., McDonald-Jones, G., Bruce, J., Lee, E.B., Xie, S.X., Joyce, S., Li, C., Toleikis, P.M., Lee, V.M.-Y., Trojanowski, J.Q. Microtubule-binding drugs offset tau sequestration by stabilizing microtubules and reversing fast axonal transport deficits in a tauopathy model. Proceedings of the National Academy of Science 102(1):227-231, 2005.

Siderowf, A., Jaggi, J.L., Xie, S.X., Loveland-Jones, C., Leng, L., Hurtig, H., Colcher, A., Stern, M., Chou, K.L., Liang, G., Maccarone, H., Simuni, T., Baltuch, G. Long-term effects of bilateral subthalamic nucleus stimulation on health-related quality of life in advanced Parkinson's disease. Movement Disorders 21(6): 746-753, 2006.

Libon, D.J., Xie, S.X., Moore, P., Farmer, J., Antani, S., McCawley, G., Cross, K., Grossman, M. Patterns of neuropsychological impairment in frontotemporal dementia. Neurology 68:369-375, 2007.

Weintraub, D., Xie, S., Karlawish, J., Siderowf, A. Differences in depression symptoms in patients with Alzheimer's and Parkinson's diseases: evidence from the 15-item geriatric depression scale (GDS-15). International Journal of Geriatric Psychiatry 22:1025-1030, 2007

Nakashima-Yasuda, H., Uryu, K., Robinson, J., Xie, S.X., Hurtig, H., Duda, J.E., Arnold, S.E., Siderowf, A., Grossman, M., Leverenz, J.B., Woltjer, R., Lopez, O.L., Hamilton, R., Tsuang, D.W., Galasko, D., Masliah, E., Kaye, J., Clark, C.M., Montine, T.J., Lee, V.M.-Y., Trojanowski, J.Q. Co-Morbidity of TDP-43 proteinopathy in lewy body related diseases. Acta Neuropathologica 114:221-229, 2007.

Geser, F., Winton, M.J., Kwong, L.K., Xu, Y., Xie, S.X., Igaz, L.M., Garruto, R.M., Perl, D.P., Galasko, D., Lee, V.M.-Y., Trojanowski, J.Q. Pathological TDP-43 in parkinsonism-dementia complex and amyotropic lateral sclerosis of Guam. Acta Neuropathologica 115:133-145, 2008.

Xie, S.X., Forman, M.S., Farmer J., Moore, P., Wang, Y., Wang, X, Clark, C.M., Coslett, H.B., Chatterjee, A., Arnold, S.E., Rosen, H., Karlawish, J.H.T., Van Deerlin, V.M., Lee, V.M.-Y., Trojanowski, .J.Q., Grossman, M. Factors associated with survival probability in autopsy-proven frontotemporal lobar degeneration. Journal of Neurology, Neurosurgery & Psychiatry 79:126-129, 2008.

Grossman, M., Xie, S.X., Libon, D.J., Wang, X., Massimo, L., Moore, P., Vesely, L., Berkowitz, R., Chatterjee, A., Coslett, H.B., Hurtig, H.I., Forman, M.S., Lee, V.M.-Y., Trojanowski, J.Q. Longitudinal decline in autopsy-defined frontotemporal lobar degeneration. Neurology 70: 2036-2045, 2008.

Libon, D.J., Xie, S.X., Wang, X., Massimo, L., Moore, P., Vesely, L., Khan, A., Chatterjee, A., Coslett, H.B., Hurtig, H.I., Liang, T.-W., Grossman, M. Neuropsychological decline in frontotemporal lobar degeneration: A Longitudinal Analysis. Neuropsychology 23: 337-346, 2009.

Geser, F., Martinez-Lage, M., Robinson, J., Uryu, K., Newmann, M., Brandmeir, N.J., Xie, S.X., Kwong, L.K., Elman, L., McCluskey, L., Clark, C.M., Malunda, J., Miller, B.L., Zimmerman, E., Qian, J., Van Deerlin, V., Grossman, M., Lee, V.M.-Y., Trojanowski, J.Q. Clinical and pathological continuum of multisystem TDP-43 proteinopathies. Archives of Neurology 66(2): 180-189, 2009.

Xie, S.X., Ewbank, D.C., Chittams, J., Karlawish, J.H.T., Arnold, S.E., Clark, C.M. Rate of decline in Alzheimer disease measured by a dementia severity rating scale. Alzheimer Disease & Associated Disorders 23:268-274, 2009.

Xie, S.X., Libon, D.J., Wang, X., Massimo, L., Moore, P., Vesely, L., Khan, A, Chatterjee, A., Coslett, H.B., Hurtig, H.I., Liang, T.-W., Grossman M. Longitudinal patterns of semantic and episodic memory in frontotemporal lobar degeneration and Alzheimer's Disease. Journal of the International Neuropsychological Society 16:278-286, 2010.

Trojanowski, J.Q., Arnold, S., Karlawish, J., Brunden, K., Cary, M., Davatzikos, C., Detre, J., Gaulton, G., Grossman, M., Hurtig, H., Jedrziewski, K., McCluskey, L., Naylor M, Polsky, D., Schellenberg, G.D., Siderowf, A., Shaw, L.M., Van Deerlin, V., Wang, L.-S., Werner, R, Xie, S.X., Lee, V.M-Y. Design of comprehensive Alzheimer's Disease Centers to address unmet national needs. Alzheimer's & Dementia 6:150-155, 2010.

Geser, F., Robinson, J.L., Malunda, J.A., Xie, S.X., Clark, C.M., Kwong, L.K., Moberg, P.J., Moore, E., Van Deerlin, V.M., Lee, V.M.-Y., Arnold, S.E., Trojanowski, J.Q. Pathological TDP-43 in older adults with and without severe mental illness. Archives of Neurology (in press, 2010).

Siderowf, A., Xie, S.X., Hurtig, H., Weintraub, D., Duda, J., Chen-Plotkin, A., Shaw, L.M., Van Deerlin, V., Trojanowski, J.Q., Clark, C. CSF Amyloid Beta 1-42 predicts cognitive decline in Parkinson's disease. Neurology (in press, 2010).

Xie, S.X.*, Baek, Y.*, Grossman, M., Arnold, S.E., Karlawish, J., Siderowf, A., Hurtig, H., Elman, L., McCluskey, L., Van Deerlin, V., Lee, V.M.-Y., Trojanowski, J.Q. Building an integrated neurodegenerative disease database at an academic health center. Alzheimer's & Dementia (in press, 2010). * Co-first authors.



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