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Yan Ma, PhD

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Photo of Dr. Ma

Yan Ma, PhD

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Research Description

Dr. Ma’s research interests in statistical methodology center on inference for instrument reliability and rater agreement, nonparametric estimation and inference, observational studies, causal inferences, meta-analysis, complex survey data analysis, longitudinal data analysis, and missing data problems. He has successfully developed U-statistics based non-parametric estimators for a series of correlation and agreement indices including kappa, concordance correlation coefficient, and Cronbach’s coefficient alpha.

Dr. Ma’s areas of applications include HIV/AIDS, psychiatry, orthopedics, and anesthesiology. 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, he is very interested in studying the outcomes associated with rare events such as perioperative death and other complications following orthopedic surgery using large national database such as the National Health and Nutrition Examination Survey (NHANES) and the Nationwide Inpatient Sample (NIS).

Dr. Ma is statistical editor for Aesthetic Plastic Surgery and reviewer for Biostatistics, CHEST, Journal of Bone and Joint Surgery, Journal of Applied Statistics, Journal of Orthopedic Research, Psychology and Aging, and Statistics in Medicine.

Selected Publications

Ma Y, Tang W, Feng C, Tu XM. (2008). Inference for kappas for longitudinal study data: applications to sexual health research. Biometrics, 64: 781-789.

Ma Y, Tang W, Yu Q, Tu XM. (2009). Modeling concordance correlation coefficient for longitudinal data. Psychometrika, 75: 99-119.

Memtsoudis SG, Ma Y, González Della Valle A, Mazumdar M, Gaber-Baylis LK, MacKenzie CR, Sculco TP (2009): Perioperative outcomes after unilateral and bilateral total knee arthroplasty. Anesthesiology, 111:1206-16.  Accompanied by editorial: Perioperative Comparative Effectiveness Research, Anesthesiology, 111: 1180-2

Marawar S, Girardi FP, Sama AA, Ma Y, Gaber LK, Besculides MC, Memtsoudis SG. (2009). National trends in anterior cervical fusion procedures. (In press in Spine)

Ma Y, Gonzalez Della Valle A, Zhang H, Tu, X.M. (2010). A U-statistics based  approach for modeling cronbach coefficient alpha within a longitudinal data setting.  Statistics in Medicine; 29: 65-670.

Weskamp G, Mendelson K, Swendeman S, Le Gall S, Ma Y, Lyman S, Hinoki A, Eguchi S, Guaiquil V, Horiuchi K, Blobel CP. Pathological neovascularization is reduced by inactivation of ADAM17 in endothelial cells, but not in pericytes.  Circulation Research, 2010; 106:932-940

Brophy RH, Backus SI, Kraszewski AP, Steele BC, Ma Y, Osei D, Williams RJ. (2010). Gender differences in lower extremity alignment and muscle activation during the soccer kick. (In press in Journal of Bone and Joint Surgery)

Memtsoudis SG, Ma Y, Chiu YL, Walz JM, Voswinckel R, Mazumdar M. (2010). Perioperative mortality in patients with pulmonary hypertension undergoing major joint replacement. (In press in Anesthesia & Analgesia

For more publications, please see the PubMed listing.


Assistant Scientist, Hospital for Special Surgery
Assistant Professor of Biostatistics, Department of Public Health, Weill Cornell Medical College