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U.S. Department of Health and Human Services

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Ram C. Tiwari, Ph.D.

Ram C. Tiwari, Ph.D. 

Ram C. Tiwari, Ph.D.

Associate Director, Office of Biostatistics
Center for Drug Evaluation & Research, FDA
White Oak Campus, Silver Spring, MD


M.S. & Ph.D. (Mathematical Statistics), Florida State University
Fellow, American Statistical Association
Member, International Statistical Institute
Previous Employment: Mathematical Statistician and Program Director, Surveillance
Research program, NCI/NIH (2000-2008);
Professor & Chairman, Department of Mathematics, University
of North Carolina, Charlotte, NC (1994-2000);
Asst./Assoc./Professor, Department of Mathematics, University
of North Carolina, Charlotte, NC (1986-1994);
Asst. Professor, Indian Institute of Technology, Bombay (2002-
2006); Visiting Lecturer, UC Santa Barbara (1981-1982, 1985-1986).

Research Interests

i) Bayesian approaches for clinical trials; ii) signal detection in drug safety surveillance; and iii) meta-analysis

Proposed Research Project for an FDA Commissioner's Fellow

  • Meta-analysis of safety data from clinical studies using likelihood ratio test (LRT)
  • Background: Basic understanding of statistical inference and meta-analysis.

Research Plan

Fellow would spend considerable time in understanding the in-house developed LRT methods and tool, and its extension to clinical trials’ safety data. Meta-analysis has become a common approach for evaluating risk from use of drugs in the targeted patient population by combining relevant safety data from multiple clinical studies. The project intends to implement LRT methods to conduct meta-analysis to find the signals.

Project Requirements: Ph.D. in Biostatistics, with the knowledge of SAS and R

The FDA Regulatory Science Priority Area for the project is Harness Diverse Data through Information Sciences to Improve Health Outcomes.

Applicant Requirements: Ph.D. in (Bio)statistics, with the knowledge of SAS and R

Selected Recent Publications

1. McEvoy, B., Nandy, R.R., and Tiwari, R.C. Bayesian approach for clinical trial safety data using an Ising prior, Biometrics, 69 (2013), 661-672.

2. Cook AJ, Wellman RD, Tiwari RC, Li L, Heckbert S, March T, Heagerty P, Nelson JC. Statistical approaches to group sequential monitoring of postmarket safety surveillance data: Current state of the art for use in the mini-sentinel pilot, Pharmacoepidemiology and Drug Safety 2012; 21, 72-81.

3. Huang, L, Zalkikar J, Tiwari R. A likelihood ratio test based method for signal detection with application to FDA's drug safety data, Jour. Amer. Statist. Assoc., 106 (2011): 1230-1241.

4. Cook, A.J., Li, Y., Arterburn, D., and Tiwari, R.C. Spatial cluster detection for weighted outcomes using cumulative geographic residuals, Biometrics , 66 (2010), 783- 792.

5. Huang, L., Tiwari, R.C., Zou, Z., Kulldorff, M., and Feuer, E.J. Weighted normal spatial scan statistic for heterogeneous population data, Jour. Amer. Statist. Assoc., 104 (2009), 886-898.