Abstract
Population pharmacokinetic (PK) modeling methods can be statistically classified as either parametric or nonparametric (NP). Each classification can be divided into maximum likelihood (ML) or Bayesian (B) approaches. In this paper we discuss the nonparametric case using both maximum likelihood and Bayesian approaches. We present two nonparametric methods for estimating the unknown joint population distribution of model parameter values in a pharmacokinetic/pharmacodynamic (PK/PD) dataset. The first method is the NP Adaptive Grid (NPAG). The second is the NP Bayesian (NPB) algorithm with a stick-breaking process to construct a Dirichlet prior. Our objective is to compare the performance of these two methods using a simulated PK/PD dataset. Our results showed excellent performance of NPAG and NPB in a realistically simulated PK study. This simulation allowed us to have benchmarks in the form of the true population parameters to compare with the estimates produced by the two methods, while incorporating challenges like unbalanced sample times and sample numbers as well as the ability to include the covariate of patient weight. We conclude that both NPML and NPB can be used in realistic PK/PD population analysis problems. The advantages of one versus the other are discussed in the paper. NPAG and NPB are implemented in R and freely available for download within the Pmetrics package from www.lapk.org.
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References
FDA (1999) FDA guidance for industry: population pharmacokinetics
Beal S, Sheiner L (1982) Estimating population kinetics. Crit Rev Biomed Eng 8(3):95–222
Beal S, Sheiner L (1992) NONMEM User’s Guide. In: Nonlinear mixed effects models for repeated measures. University of California, San Francisco
Lavielle M, Mentré F (2007) Estimation of population pharmacokinetic parameters of saquinavir in HIV patients with the MONOLIX software. J Pharmacokinet Pharmacodyn 34(2):229–249
D’Argenio D, Schumitzky A, Wang X (2009) ADAPT 5 User’s guide:pharmacokinetic/pharmacodynamic systems analysis Software. Biomedical Simulations Resource, Los Angeles
Wang A, Schumitzky A, DArgenio D (2007) Nonlinear random effects mixture models: maximum likelihood estimation via the EM algorithm. Comput Stat Data Anal 51:6614–6623
Wang A, Schumitzky A, DArgenio D (2009) Population pharmacokinet-ic/pharmacodyanamic mixture models via maximum a posteriori estimation. Comput Stat Data Anal 53:3907
Lindsay B (1983) The geometry of mixture likelihoods: a general theory. Ann Stat 11:86–94
Mallet A (1986) A maximum likelihood estimation method for random coefficient regression models. Biometrika 73:645–656
Kiefer J, Wolfowitz J (1956) Consistency of the maximum likelihood estimator in the presence of infinitely many incidental parameters. Ann Math Stat 27(4):887–906
Baverel P, Savic R, Karlsson M (2011) Two bootstrapping routines for obtaining imprecision estimates for nonparametric parameter distributions in nonlinear mixed effects models. J Pharmacokinet Pharmacodyn 38(1):63–82
Spiegelhalter DJ, Thomas A, Best NG (2004) WinBUGS Version 1.4 User Manual, MRC Biostatistics Unit
Plummer M (2003) JAGS: A program for analysis of Bayesian Graphical Models Using Gibbs Sampling. Proceedings of the 3rd International Workshop on Distributed Statistical Computing (DSC 2003), Vienna
Wakefield J, Walker S (1997) Bayesian nonparametric population models: formulation and comparison with likelihood approaches. J Pharmacokinet Biopharm 25:235–253
Wakefield J, Walker S (1998) Population models with a nonparametric random coefficient distribution. Sankhya Ser B 60:196–212
Mueller P, Rosner G (1997) A Bayesian population model with hierarchical mixture priors applied to blood count data. J Am Stat Assoc 92:1279–1292
Rosner G, Mueller P (1997) Bayesian population pharmacokinetic and pharmacodynamic analyses using mixture models. J Pharmacokinet Biopharm 25:209–233
Wang J (2010) Dirichlet processes in nonlinear mixed effects models. Commun Stat Simul Comput 39:539–556
Yamada Y, Bartroff J, Bayard D, Burke J, Van Guilder M, RW J, et al. (2012) The nonparametric adaptive grid algorithm for population pharmacokinetic modeling. Technical Report, LAPK, USC, Laboratory of Applied Pharmacokinetics
Neely M, Tatarinova T, Bartroff J, Van Guilder M, Yamada W, Bayard D, et al (2012) Non-parametric Bayesian fitting: a novel approach to population pharmacokinetic modeling. Poster presented at: Population Analysis Group in Europe, Venice
Neely M, van Guilder M, Yamada W, Schumitzky A, Jelliffe R (2012) Accurate detection of outliers and subpopulations with Pmetrics, a nonparametric and parametric pharmacometric modeling and simulation package for R. Ther Drug Monit 34(4):467–476
Bustad A, Terziivanov D, Leary R, Port R, Schumitzky A, Jelliffe R (2006) Parametric and nonparametric population methods: their comparative performance in analysing a clinical dataset and two Monte Carlo simulation studies. Clin Pharmacokinet 45(4):365–383
Ishwaran H, James L (2001) Gibbs sampling methods for stick-breaking priors. J Am Stat Assoc 96:161–173
Jelliffe R, Bayard D, Milman M, Van Guilder M, Schumitzky A (2000) Achieving target goals most precisely using nonparametric compartmental models and “multiple model” design of dosage regimens. Ther Drug Monit 22:346–353
Schumitzky A (1991) Nonparametric EM algorithms for estimating prior distributions. Appl Math Comput 45:141–157
Leary R, Jelliffe R, Schumitzky A, Van Guilder M (2001) An adaptive grid non-parametric approach to population pharmacokinetic/dynamic (PK/PD) population models. Proceedings, 14th IEEE symposium on computer based medical systems, pp 389–394
Baek Y (2006) An interior point approach to constrained nonparametric mixture models. PhD Dissertation, Thesis supervisor: Prof. James Burke, University of Washington, Department of Mathematics
Fox BL (1986) Algorithm 647: implementation and relative efficiency of Quasirandom sequence generators. Trans Math Softw 12(4):362–376
Karush W (1939) Minima of functions of several variables with inequalities as side constraints. MSc disseertation, University of Chicago, Department of Mathematics, Chicago
Kuhn H, Tucker A (1951) Nonlinear programming. Proceedings of the 2nd Berkeley Symposium, pp 481–492
Papaspiliopoulos O, Roberts GO (2008) Retrospective Markov chain Monte Carlo methods for Dirichlet process hierarchical models. Biometrika 95(1):169–186
Sethuraman J (1994) A constructive definition of Dirichlet priors. Statistica Sinica 4:639–650
Tatarinova T (2006) Bayesian analysis of linear and nonlinear mixture models. USC, Los Angeles
Tatarinova T, Bouck J, Schumitzky A (2008) Kullback-Leibler Markov chain Monte Carlo—a new algorithm for finite mixture analysis and its application to gene expression data. J Bioinform Comput Biol 6(4):727–746
Frühwirth-Schnatter S (2010) Finite mixture and markov switching models, 1st edn. Springer, New York
Ghosh P, Rosner G (2007) A semiparametric Bayesian approach to average bioequivalence. Stat Med 26:1224–1236
Ohlssen D, Sharples L, Spiegelhalter D (2007) Flexible random-effects models using Bayesian semi-parametric models: applications to institutional comparisons. Stat Med 26:2088–2112
Walker S (2007) Sampling the Dirichlet mixture model with slices. Commun Stat Simul Comput 36:45–54
Kalli M, Griffen J, Walker S (2011) Slice sampling mixture models. Stat Comput 21:93–105
Plummer M (2011) rjags: Bayesian graphical models using MCMC
Robert C (2007) The Bayesian choice, 2nd edn. Springer, New York
Robert C, Casella G (2004) Monte Carlo statistical methods, 2nd edn. Springer, New York
Dunson D (2010) Nonparametric Bayes applications to biostatistics. In: Hjort N, Holmes C, Muller P, Walker S (eds) Bayesian nonparametrics. Cambridge University Press, Cambridge, pp 223–268
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Support from NIH: GM068968, EB005803, EB001978, NIH-NICHD: HD070996 and Royal Society: TG103083 is gratefully acknowledged.
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Tatarinova, T., Neely, M., Bartroff, J. et al. Two general methods for population pharmacokinetic modeling: non-parametric adaptive grid and non-parametric Bayesian. J Pharmacokinet Pharmacodyn 40, 189–199 (2013). https://doi.org/10.1007/s10928-013-9302-8
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DOI: https://doi.org/10.1007/s10928-013-9302-8