I have moved to Department of Preventive Medicine at Northwestern University. Please visit me at

 

http://www.preventivemedicine.northwestern.edu/index.htm

 

I have a broad interest in survival analysis and longitudinal data analysis, with applications to clinical and health services studies. I am particularly interested in the analysis of medical cost data and joint models of longitudinal and survival data. Recently I am working on non/semiparametric regression methods (e.g., penalized splines), causal inference in observational studies, and adaptive design in early phase clinical trials. I also collaborate with clinicians in psychiatric medicine, asthma, infectious diseases, kidney diseases and diabetes. Since 2007, I have been PI of three NIH and AHRQ grants, developing and applying innovative statistical methods to medical cost data and alcohol treatment data. I am associate editor of Statistics in Medicine.

 

My CV.

 

Here is my contact information:

 

P.O. Box 800717
Tel:  1-434-982-3364
Fax: 1-434-243-5787
Email: liulei@virginia.edu
 
PUBLICATIONS

Statistical Papers

1.     Liu, L., Wolfe, R. A., and Huang, X. (2004). Shared frailty models for recurrent events and a terminal event. Biometrics 60, 747-756.

2.     Liu, L., Wolfe, R. A., and Kalbfleisch, J. D. (2007). A random effects model for censored medical costs. Statistics in Medicine 26, 139-155.

3.     Huang, X. and Liu, L. (2007). A joint frailty model for survival time and gap times between recurrent events. Biometrics 63, 389-397.

4.     Liu, L., Conaway, M. R., Knaus, W. A. and Bergin, J. (2008). A random effects four-part model, with application to correlated medical costs. Computational Statistics and Data Analysis 52, 4458-4473.

5.     Liu, L., Huang, X. and O’Quigley, J. (2008). Analysis of longitudinal data in the presence of informative observational times and a dependent terminal event, with application to medical cost data. Biometrics 64, 950-958.

6.     Liu, L. and Huang, X. (2008). The use of Gaussian quadrature in frailty proportional hazards models. Statistics in Medicine 27, 2665-2683.

7.     Liu, L. and Yu, Z. (2008). Likelihood reformulation method in non-normal random effects models. Statistics in Medicine 27, 3105-3124.

8.     Liu, L., Ma, J. Z., and Johnson, B. (2008). A multi-level two-part random effects model, with application to an alcohol dependence study. Statistics in Medicine 27, 3528-3539.

9.     Liu, L., Ma, J. Z., and O’Quigley, J. (2008). Joint analysis of multi-level repeated measures data and survival: an application to the end stage renal disease (ESRD) data. Statistics in Medicine 27, 5679–5691.

10.  Liu, L. and Huang X. (2009). Joint analysis of correlated repeated measures and recurrent events processes in the presence of a dependent terminal event. Applied Statistics 58, 65-81.

Selected as “Don’t miss these papers” in the JRSS’s website (only paper in this issue). Here is a sample SAS code for the paper.

11.  Liu, L. (2009). Joint modeling longitudinal semi-continuous data and survival, with application to longitudinal medical cost data. Statistics in Medicine 28, 972-986.

12.  Liu, L., Strawderman, R., Cowen, M., and Shih, T. (2010). A flexible two-part random effects model for correlated medical costs. Journal of Health Economics 29, 110-123.

13.  Yu, Z. and Liu, L. A joint model of recurrent events and a terminal event with a nonparametric covariate function. Statistics in Medicine 30, 2683-2695.

14.  Chen, J., Liu, L.*, Johnson, B. A., and O'Quigley, J. New estimation method for nonparametric mixed models, with application to alcohol treatment research. Submitted. (*: Correspondence Author, the first author is a postdoc under my supervision)

Medical Papers

 

1.     Marozkina NV, Wei C, Yemen S, Wallrabe H, Nagji AS, Liu L, Morozkina T, Jones DR, Gaston B. S-Nitrosoglutathione reductase in human lung cancer. Submitted.

2.     Chen, J., Johnson, B., Wang, X. Q., O'Quigley, J., Isaac M, and Liu, L.* Trajectory analyses in alcohol treatment research. Alcoholism: Clinical and Experimental Research. Accepted. (*: Correspondence author, the first author is a postdoc under my supervision).

3.     Minak, J., Kabir,  M., Mahmud, I., Liu, Y., Liu, L., Haque, R., and Petri W.A. (2011). Evaluation of Rapid Antigen Point-of-Care Tests for Detection of Giardia and Cryptosporidium Species in Human Fecal Specimens. Journal of Clinical Microbiology. In press.

4.     Mondal, D., Minak, J., Alam, M.,  Liu, Y., Dai, J., Korpe, P., Liu, L., Haque, R., and Petri W.A. (2011). Contribution of Enteric Infection, Altered Intestinal Barrier Function, and Maternal Malnutrition to Infant Malnutrition. Clinical Infectious Diseases. Accepted.

5.     Johnson, B. A., Ait-Daoud, N., Li, M. D., Seneviratne, C., Roache, J. D., Javors, M. A., Wang, X-Q,  Liu, L., Penberthy, J. K., DiClemente, C. C. Serotonin Transporter Polymorphisms and mRNA Expression Level Predict Therapeutic Response to a Serotonin-3 Antagonist to Treat Binge Drinking Among Alcohol-Dependent Outpatients. American Journal of Psychiatry. Accepted.

Reported in the front page of the Wall Street Journal. Highlighted in JAMA.

6.      Liu, L., Teague, W. G., Mantri, S., Dweik, R. A., Gaston, B, for the National Heart Lung Blood Institute Severe Asthma Research Program (SARP). Determinants of exhaled breath condensate pH in a large asthma population. Chest. Accepted.

7.     Thomas,  T. A., Mondal, D, Alam, M., Liu, L., Sun, H., Haque, R., Banu, S., Peterson, K. M. Malnutrition and helminth infection affect performance of an interferon gamma release assay for diagnosing latent tuberculosis infection in children. Pediatrics. Accepted.

8.     Falk, D., Wang, X-Q, Liu, L., Fertig, J., Mattson, M., Ryan, M., Johnson, B., Stout, R., and Litten, R. Z. (2010). Percentage of subjects with no heavy drinking days: evaluation as an efficacy endpoint for alcohol clinical trials. Alcoholism: Clinical and Experimental Research 34, 2022-2034.

9.     Marozkina, N., Borowitz, M., Yemen, S., Liu, L., Sun, F., Islam, R., Erdmann-Gilmore,  P., Townsend, R. R., Lichti, C., Mantri, S., Gaston, B., Zaman, K. (2010). S-Nitrosoglutathione targets Hsp 70/Hsp 90 organizing protein as a corrector therapy for cystic fibrosis.  Proceedings of the National Academy of Sciences of the United States of America 107, 11393-11398.

10.  Liu, L., Urban P., Hunt, J. F., Wilkinson P., Laning K., Gaston, B. (2010). Changes in exhaled NO and breath pH during fluticasone wean in asthma. Respiration 79, 193–199.

Editorial by Basek in p. 187–188.

11.  Ait-Daoud, N., Roache, J.D., Dawes, M.A., Liu, L., Wang, X.-Q., Javors, M.A., Seneviratne, C., Johnson, B.A. (2009): Can serotonin transporter genotype predict craving in alcoholism? Alcoholism: Clinical and Experimental Research 33, 1329-1335.

12.  Johnson, B.A., Roache, J.D., Ait-Daoud, N., Wells, L.T., Wallace, C.L., Dawes, M.A., Liu, L., Wang, X.-Q. (2007). Effects of acute topiramate dosing on methamphetamine-induced subjective mood. The International Journal of Neuropsychopharmacology, 10 (1): 85-98.

13.  Johnson, B.A., Roache, J.D., Ait-Daoud, N., Wells, L.T., Wallace, C.L., Dawes, M.A., Liu, L., Wang, X.-Q. (2007). Effects of topiramate on methamphetamine-induced changes in attentional and perceptual-motor skills of cognition in recently abstinent methamphetamine-dependent individuals. Progress in Neuro-Psychopharmacology and Biological Psychiatry 31 (1): 123-130

14.  Johnson, B.A., Wells, L.T., Roache, J.D., Wallace, C.L., Ait-Daoud, N., Dawes, M.A., Liu, L., Wang, X.-Q., Javors, M.A. (2007). Kinetic and cardiovascular effects of acute topiramate dosing among non-treatment-seeking, methamphetamine-dependent individuals. Progress in Neuro-Psychopharmacology and Biological Psychiatry 31, 455-461.

15.  Bissram, M., Scott, F. D., Liu, L., Rosner, M. H. (2007). Risk factors for symptomatic hyponatraemia: the role of pre-existing asymptomatic hyponatraemia. Internal Medicine Journal 37. 149-155.

16.  Li, Y., Oskouian, R. J., Day, Y., Rieger, J. M., Liu, L., Kern, J. A., and Linden, J. (2006). Mouse spinal cord compression injury is reduced by either activation of the adenosine A2a  receptor on bone marrow-derived cells or deletion of the A2a  receptor on non-bone marrow-derived cells. Neuroscience. 141, 2029-2039.

17.  Zaman, K., Carraro, S., Doherty, J., Henderson, E. M., Lendermon, E., Liu, L., Verghese, G., Zigler, M., Ross, M., Park, E., Palmer, L., Doctor, A., Stamler, J., Gaston. B. (2006). A Novel class of compounds that increase CFTR expression and maturation in epithelial cells. Molecular Pharmacology 70. 1435-1442.

18.  Gaston, B., Kelly, R., Urban, P., Liu, L., Teague, W. G., Fitzpatrick, A., Erzurum, S., Hunt, J. F. (2006). Buffering airway acid decreases exhaled nitric oxide in asthma. Journal of Allergy and Clinical Immunology. 118, 817-822.

19.  Perlman, R. L., Finkelstein, F., Liu, L., Roys, E., Kiser, M., Eisele, G., Burrows-Hudson, S., Messana, J. M., Levin, N., Rajagopalan, S. R., Port, F. K., Wolfe, R. A., Saran, R. (2005). Quality of Life in Chronic Kidney Disease (CKD): a Cross-sectional Analysis in the Renal Research Institute-CKD Study. American Journal of Kidney Disease 45. 658-666.

20.  Bailey, G., Eisele, G., Liu, L., Roys, E., Kiser, M., Finkelstein, F., Wolfe, R., Port, F., Burrows-Hudson, S., Saran, R. (2005). Patterns of Medication use in the RRI-CKD Study: Focus on Medications with Cardiovascular Effects. Nephrology Dialysis Transplantation 20. 1110-1115.

21.  Ilag, L., Kronick, S., Ernst, R., Grondin, L., Alaniz, C., Liu, L., Herman, W. (2003). Impact of a critical pathway on inpatient management of diabetic ketoacidosis. Diabetes Research and Clinical Practice 62, 23-32.

22.  Perlman, R. L., Kiser, M., Finkelstein, F., Eisele, G., Roys, E., Liu, L., Burrows-Hudson, S., Port, F., Messana, J. M., Bailie, G., Rajagopalan, S., Saran R. (2003). The longitudinal chronic kidney disease study: a prospective cohort study of pre-dialysis renal failure. Seminar in Dialysis 16, 418-423.