Biostatistics and Epidemiology
Faculty and Staff
Yan Ma, Ph.D., M.A., M.S., is an Assistant Professor of Biostatistics in the Division of Biostatistics and Epidemiology in the Department of Public Health at Weill Medical College of Cornell University and Assistant Professor of Biostatistics in the Research Division at the Hospital for Special Surgery. He received his Ph.D. in Statistics from the University of Rochester. He has already published over 60 peer reviewed papers. In 2010, he was a recipient of Statistics in Epidemiology Young Investigator Award by the American Statistical Association. In 2012, Dr. Ma and his collaborators won the esteemed Team Science Award from the Association for Clinical Research Training [ACRT], American Federation for Medical Research [AFMR], Association for Patient Oriented Research [APOR], and Society for Clinical and Translational Science [SCTS]. This award recognizes the team's success in translation of research discoveries into clinical practice.
Dr. Ma’s research interests in statistical methodology center on non-parametric methods, meta-analysis, causal inferences, longitudinal data analysis, and missing data problems. He has developed novel non-parametric statistical methods for estimation of higher order moments based on U-statistic. These methods have been applied to the estimation of inter-rater reliability (e.g., Kappa coefficient, concordance correlation coefficient) and correlation (e.g., Kendall’s tau) in longitudinal data settings with missing data. Dr. Ma has also innovatively developed a robust statistical method for multivariate meta-analysis. In addition, Dr. Ma is interested in causal inferences and has proposed an approach to address the inference about principal causal effects when there are two active treatments with continuous measures of compliance. Based on his research, Dr. Ma developed software, KappaR, which assesses inter-rater agreement in a longitudinal setting and is available on CTSPedia. A software package umeta for the use of the meta-analytic method proposed by Drs. Ma and Mazumdar, is available in Stata.
Dr. Ma’s areas of applications include orthopedics, anesthesiology, and psychiatry. He has been collaborating with investigators across the departments at the Hospital for Special Surgery, providing statistical consulting assistance in study design, grant proposal, and data analysis utilizing rigorous statistical methods. In particular, Dr. Ma and his collaborators are interested in comparative effectiveness research in the fields of orthopedics and anesthesiology. They have used nationally representative databases (HCUP-NIS, NSAS, NHANES) to study perioperative outcomes including morbidity, mortality, and safety for different surgical approaches and anesthetic techniques. Some of the results have led to supplemental clinical studies and changed policy for patient selection at the institutional level.
Dr. Ma’s research topics include:
- Instrument reliability, rater agreement, missing data (Biometrics 2008; Psychometrika 2009; Stat in Med 2010; J appl stat 2012)
- Meta-analysis (Stat in Med 2012; JBJS 2012; Knee Surg Sports Traumatol Arthrosc 2012; J Hand Surg Am 2012; J Trauma Acute Care Surg 2012)
- Causal inferences (Stat in Med 2011)
- Longitudinal data analysis (Reg Anesth Pain Med 2012)
- Perioperative outcome research for major orthopedic surgery (e.g., Anesthesiology 2009; Am J Orthop 2010; Spine 2011; JBJS 2012)
- Comparative effectiveness research for difference anesthesia techniques (e.g., Reg Anesth Pain Med 2010; J Clin Anesth 2012)
- Obstructive sleep apnea (Patient Saf Surg 2010; HSS J 2011; Anesth Analg 2011)
- Sports medicine (JBJS 2010; Am J Sports Med 2012)
- Mental health (Arch Suicide Res 2007; J Clin Psy 2010; Int Psychogeriatr 2011; Psychol Aging 2011)
- Biomechanics (Am J Sports Med 2012; Bone 2013)
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