@article {liu_asymptotic_2010,
	title = {Some asymptotic results for semiparametric nonlinear mixed-effects models with incomplete data},
	journal = {Journal of Statistical Planning and Inference},
	volume = {140},
	number = {1},
	year = {2010},
	month = {jan},
	pages = {52{\textendash}64},
	abstract = {In modeling complex longitudinal data, semiparametric nonlinear mixed-effects (SNLME) models are very flexible and useful. Covariates are often introduced in the models to partially explain the inter-individual variations. In practice, data are often incomplete in the sense that there are often measurement errors and missing data in longitudinal studies. The likelihood method is a standard approach for inference for these models but it can be computationally very challenging, so computationally efficient approximate methods are quite valuable. However, the performance of these approximate methods is often based on limited simulation studies, and theoretical results are unavailable for many approximate methods. In this article, we consider a computationally efficient approximate method for a class of SNLME models with incomplete data and investigate its theoretical properties. We show that the estimates based on the approximate method are consistent and asymptotically normally distributed.},
	keywords = {Approximation, Asymptotics, Longitudinal data, Measurement error},
	issn = {0378-3758},
	doi = {10.1016/j.jspi.2009.06.006},
	url = {http://www.sciencedirect.com/science/article/pii/S0378375809001888},
	author = {Liu, Wei and WU, LANG}
}
@article {wu_flexible_2002,
	title = {Flexible Weighted Log-Rank Tests Optimal for Detecting Early and/or Late Survival Differences},
	journal = {Biometrics},
	volume = {58},
	number = {4},
	year = {2002},
	month = {dec},
	pages = {997{\textendash}1004},
	abstract = {Summary. At the present time, many AIDS clinical trials compare drug therapies by a time-to-event primary endpoint that measures the durability of suppression of HIV replication. For such studies, survival differences tend to occur early and/or late in the follow-up period due to drug differences in initial potency and/or durability of efficacy, and detecting these differences is of primary interest. We propose a weighted log-rank statistic that emphasizes early and/or late survival differences. We also consider some versatile tests that also emphasize these differences but are sensitive to a wider range of alternatives. The performances of the new tests are evaluated in numerical studies. For the alternatives of interest, the new tests show greater power and flexibility than commonly used weighted log-rank tests and related versatile tests. When the main interest is in detecting early and/or late survival differences, these tests may be preferable to the other versatile and weighted log-rank tests that have been studied.},
	keywords = {AIDS, Asymptotics, Quadratic weight, Robust test, Versatile test},
	issn = {1541-0420},
	doi = {10.1111/j.0006-341X.2002.00997.x},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/j.0006-341X.2002.00997.x/abstract},
	author = {WU, LANG and Gilbert, Peter B.}
}
