PMID- 18004656
OWN - NLM
STAT- MEDLINE
DCOM- 20080408
LR  - 20211020
IS  - 1380-7870 (Print)
IS  - 1380-7870 (Linking)
VI  - 13
IP  - 4
DP  - 2007 Dec
TI  - A semiparametric pseudo-score method for analysis of two-phase studies with 
      continuous phase-I covariates.
PG  - 607-22
AB  - Two-phase study designs can reduce cost and other practical burdens associated 
      with large scale epidemiologic studies by limiting ascertainment of expensive 
      covariates to a smaller but informative sub-sample (phase-II) of the main study 
      (phase-I). During the analysis of such studies, however, subjects who are 
      selected at phase-I but not at phase-II, remain informative as they may have 
      partial covariate information. A variety of semi-parametric methods now exist for 
      incorporating such data from phase-I subjects when the covariate information can 
      be summarized into a finite number of strata. In this article, we consider 
      extending the pseudo-score approach proposed by Chatterjee et al. (J Am Stat 
      Assoc 98:158-168, 2003) using a kernel smoothing approach to incorporate 
      information on continuous phase-I covariates. Practical issues and algorithms for 
      implementing the methods using existing software are discussed. A sandwich-type 
      variance estimator based on the influence function representation of the 
      pseudo-score function is proposed. Finite sample performance of the methods are 
      studies using simulated data. Advantage of the proposed smoothing approach over 
      alternative methods that use discretized phase-I covariate information is 
      illustrated using two-phase data simulated within the National Wilms Tumor Study 
      (NWTS).
FAU - Chatterjee, Nilanjan
AU  - Chatterjee N
AD  - Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, 
      DHHS, Rockville, MD 20852, USA. chattern@mail.nih.gov
FAU - Chen, Yi-Hau
AU  - Chen YH
LA  - eng
PT  - Journal Article
DEP - 20071114
PL  - United States
TA  - Lifetime Data Anal
JT  - Lifetime data analysis
JID - 9516348
SB  - IM
MH  - Case-Control Studies
MH  - Cohort Studies
MH  - Computer Simulation
MH  - *Data Interpretation, Statistical
MH  - *Epidemiologic Research Design
MH  - Humans
MH  - Kidney Neoplasms/epidemiology/therapy
MH  - Neoplasm Recurrence, Local/epidemiology
MH  - Regression Analysis
MH  - Wilms Tumor/epidemiology/therapy
EDAT- 2007/11/16 09:00
MHDA- 2008/04/09 09:00
CRDT- 2007/11/16 09:00
PHST- 2007/10/01 00:00 [received]
PHST- 2007/10/09 00:00 [accepted]
PHST- 2007/11/16 09:00 [pubmed]
PHST- 2008/04/09 09:00 [medline]
PHST- 2007/11/16 09:00 [entrez]
AID - 10.1007/s10985-007-9066-9 [doi]
PST - ppublish
SO  - Lifetime Data Anal. 2007 Dec;13(4):607-22. doi: 10.1007/s10985-007-9066-9. Epub 
      2007 Nov 14.