1.The Study and Application of Nonparametric Bayesian Methods for Benchmark Dose Estimation
Caijiao GU ; Tao WANG ; Tong WANG
Chinese Journal of Health Statistics 2017;34(6):861-865
Objective Comparing the performance of the two nonparametric Bayesian methods for benchmark dose estimating under different dose response data,then comparing them with traditional parametric methods.Methods Introduce the basic principle of the nonparametric Bayesian method based on weighted process and stochastic process separately,then compared the estimations through simulate study and instance analysis.Results The simulate study shows that the posterior estimates were reasonably close to the target true BMD value for the two nonparametric methods,and NBP2 is more desirable compared to NPB1.The nine examples indicate that the BMD estimates from the nonparametric approaches generally fall into or very near the interval of those obtained from BMDS and nonparametric approaches tend to produce lower BMDLs than the parametric modeling approaches.Conclusion The posterior estimates were reasonably close to the target true BMD value for the two nonparametric methods,especially when standard parametric models fail to fit to the data adequately.The NPB2 method is slightly bet-ter than the NPB1 method in the aspect of estimation result and the software operation speed.
2.Study on correction of data bias caused by different missing mechanisms in survey of medical expenditure among students enrolling in Urban Resident Basic Medical Insurance
Haixia ZHANG ; Junkang ZHAO ; Caijiao GU ; Yan CUI ; Huiying RONG ; Fanlong MENG ; Tong WANG
Chinese Journal of Epidemiology 2015;36(5):526-530