+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Bayesian inference in semiparametric mixed models for longitudinal data

Bayesian inference in semiparametric mixed models for longitudinal data

Biometrics 66(1): 70-78

We consider Bayesian inference in semiparametric mixed models (SPMMs) for longitudinal data. SPMMs are a class of models that use a nonparametric function to model a time effect, a parametric function to model other covariate effects, and parametric or nonparametric random effects to account for the within-subject correlation. We model the nonparametric function using a Bayesian formulation of a cubic smoothing spline, and the random effect distribution using a normal distribution and alternatively a nonparametric Dirichlet process (DP) prior. When the random effect distribution is assumed to be normal, we propose a uniform shrinkage prior (USP) for the variance components and the smoothing parameter. When the random effect distribution is modeled nonparametrically, we use a DP prior with a normal base measure and propose a USP for the hyperparameters of the DP base measure. We argue that the commonly assumed DP prior implies a nonzero mean of the random effect distribution, even when a base measure with mean zero is specified. This implies weak identifiability for the fixed effects, and can therefore lead to biased estimators and poor inference for the regression coefficients and the spline estimator of the nonparametric function. We propose an adjustment using a postprocessing technique. We show that under mild conditions the posterior is proper under the proposed USP, a flat prior for the fixed effect parameters, and an improper prior for the residual variance. We illustrate the proposed approach using a longitudinal hormone dataset, and carry out extensive simulation studies to compare its finite sample performance with existing methods.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 051762958

Download citation: RISBibTeXText

PMID: 19432777

DOI: 10.1111/j.1541-0420.2009.01227.x

Related references

Bayesian inferences for beta semiparametric-mixed models to analyze longitudinal neuroimaging data. Biometrical Journal. Biometrische Zeitschrift 56(4): 662-677, 2014

A Bayesian mixture of semiparametric mixed-effects joint models for skewed-longitudinal and time-to-event data. Statistics in Medicine 34(20): 2820-2843, 2015

Simultaneous inference for semiparametric mixed-effects joint models with skew distribution and covariate measurement error for longitudinal competing risks data analysis. Journal of Biopharmaceutical Statistics 27(6): 1009-1027, 2017

Bayesian inference on mixed-effects location scale models with skew-t distribution and mismeasured covariates for longitudinal data. Statistics in Medicine 36(16): 2614-2629, 2017

Semiparametric Bayesian inference on skew-normal joint modeling of multivariate longitudinal and survival data. Statistics in Medicine 34(5): 824-843, 2015

Bayesian inference on mixed-effects varying-coefficient joint models with skew- t distribution for longitudinal data with multiple features. Statistical Methods in Medical Research 26(3): 1146-1164, 2017

Simultaneous Bayesian inference for skew-normal semiparametric nonlinear mixed-effects models with covariate measurement errors. Bayesian Analysis 7(1): 189-210, 2012

Simultaneous Bayesian inference for linear, nonlinear and semiparametric mixed-effects models with skew-normality and measurement errors in covariates. International Journal of Biostatistics 7(1): 8, 2011

Dynamic semiparametric Bayesian models for genetic mapping of complex trait with irregular longitudinal data. Statistics in Medicine 32(3): 509-523, 2013

Bayesian variable selection and estimation in semiparametric joint models of multivariate longitudinal and survival data. Biometrical Journal. Biometrische Zeitschrift 59(1): 57-78, 2017

Bayesian semiparametric nonlinear mixed-effects joint models for data with skewness, missing responses, and measurement errors in covariates. Biometrics 68(3): 943-953, 2012

Semiparametric Bayesian inference for phage display data. Biometrics 69(1): 174-183, 2013

Application of semiparametric mixed models and simultaneous confidence bands in a cardiovascular safety experiment with longitudinal data. Journal of Biopharmaceutical Statistics 18(6): 1043-1062, 2008

Bayesian inference for two-part mixed-effects model using skew distributions, with application to longitudinal semicontinuous alcohol data. Statistical Methods in Medical Research 26(4): 1838-1853, 2017

A Bayesian semiparametric approach for incorporating longitudinal information on exposure history for inference in case-control studies. Biometrics 68(2): 361-370, 2012