We have developed a method for marginal analysis of the driving data that motivated this research. The method can be used to deal with correlation within subjects effectively. Two sources of within-subject correlation are considered: variability between subjects and serial correlation. We propose to address the variability between subjects by explicitly adjusting for subject as a fixed effect. To deal with serial correlation, we propose to use separated blocks, with a block-diagonal correlation matrix to account for as much correlation as possible within blocks, and a separation of suitable size to control the correlation between blocks. This procedure may be repeated randomly and the results will be synthesized using the multiple outputation technique. Model-based inference may be used to enhance the performance of the method, especially when the robust variance estimate performs poorly.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Zip Code
McLain, Alexander C; Albert, Paul S (2014) Modeling longitudinal data with a random change point and no time-zero: applications to inference and prediction of the labor curve. Biometrics 70:1052-60
Lai, Yinglei; Albert, Paul S (2014) Identifying multiple change points in a linear mixed effects model. Stat Med 33:1015-28
Cheon, Kyeongmi; Thoma, Marie E; Kong, Xiangrong et al. (2014) A mixture of transition models for heterogeneous longitudinal ordinal data: with applications to longitudinal bacterial vaginosis data. Stat Med 33:3204-13
Albert, Paul S; Liu, Aiyi; Nansel, Tonja (2014) Efficient logistic regression designs under an imperfect population identifier. Biometrics 70:175-84
Simons-Morton, Bruce G; Cheon, Kyeongmi; Guo, Feng et al. (2013) Trajectories of kinematic risky driving among novice teenagers. Accid Anal Prev 51:27-32
Simons-Morton, Bruce G; Zhang, Zhiwei; Jackson, John C et al. (2012) Do elevated gravitational-force events while driving predict crashes and near crashes? Am J Epidemiol 175:1075-9
Zhang, Zhiwei; Albert, Paul S (2011) Binary regression analysis with pooled exposure measurements: a regression calibration approach. Biometrics 67:636-45