I develop statistical and machine learning methods to understand the digital phenotype - the health information that is left behind in the digital data we generate in our everyday lives. My academic work centers on the analysis of routinely collected clinical data in the form of electronic health records. My work at Verily focuses on the use of passively collected data from a smartphone to understand mood and behavior.


Statistical Methodology

Gronsbell J, Liu M, Tian L, and Cai T. Efficient Estimation and Evaluation of Prediction Rules in Semi-Supervised Settings under Stratified Sampling. Under revision.

Gronsbell J, Hong C, Lie N, Lu Y, and Tian L. (2020) Exact Inference for the Random-Effect Model for Meta-Analyses with Rare Events. Statistics in Medicine, 39(3), 252-264.

Gronsbell J, Minnier J, Yu S, Liao KP, and Cai T. (2019) Automated Feature Selection of Predictors in Electronic Medical Records Data. Biometrics, 75(1), 268-277.

Gronsbell J, and Cai T. (2018) Semi-Supervised Approaches to Efficient Evaluation of Model Prediction Performance. Journal of the Royal Statistical Society: Series B, 80(3), 579-594.

Medical Informatics

Liao KP, Sun J, Cai T, Link NB, Hong C, Huang J, Huffman J, Gronsbell J, Zhang Y, Ho Y-L, Casto VM, Gainer VS, Murphy SN, O’Donnell CJ, Gaziano JM, Cho K, Szolovits P, Kohane IS, Yu S, and Cai T. (2019) High-throughput Multimodal Automated Phenotyping (MAP) with Application to PheWAS. Journal of the American Medical Informatics Association, 26(11), 1255-1262.

Yu S, Ma Y, Gronsbell J, Cai T, Ananthakrishnan AN, Gainer VS, Churchill SE, Szolovits P, Murphy SN, Kohane IS, Liao KP, and Cai T. (2018) Enabling Phenotypic Big Data with PheNorm. Journal of the American Medical Informatics Association, 25(1), 54-60.

Geva A, Gronsbell J, Cai T, Cai T, Murphy SN, Lyons JC, Heinz MM, Natter MD, Patibandla N, Bickel J, Mullen MP, and Mandl KD. (2017) A Computable Phenotype Improves Cohort Ascertainment in a Pediatric Pulmonary Hypertension Registry. The Journal of Pediatrics, 188(5), 224-231.


Aghayev A, Giannopoulos A, Gronsbell J, George E, Cai T, Steigner ML, Mitsouras D, and Rybicki FJ. (2018) Common First-Pass CT Angiography Findings Associated with Rapid Growth Rate in Abdominal Aorta Aneurysms between 3 and 5 cm in Largest Diameter. American Journal of Roentgenology, 210(2), 431-437.

Kumamaru H, Kumamaru K, Bateman BT, Gronsbell J, Cai T, Liu J, Higgins LD, Aoki S, Ohtomo K, Rybicki FJ, and Patorno E. (2016) Limited Hospital Variation in the Utilization and Yield of CT for Pulmonary Embolism in Patients Undergoing Total Hip or Knee Replacement Surgery. Radiology, 281(3), 826-834