[Estimation on gene-environment interaction in the partial case-control study].
OBJECTIVE
To introduce the approaches for estimating gene-environment interaction based on partial case-control studies.


METHODS
The effects of logistic model and log-linear model for estimating the main effects and gene-environment interaction effect were estimated by means of maximum likelihood methods in traditional case-control studies, case-only studies and partial case-control studies, respectively. An example was also illustrated.


RESULTS
In traditional case-control study with complete data, the results of logistic model and log-linear model were equivalent. In case-only study without any information about controls, the logistic model can also efficiently estimate gene-environment interaction. In partial case-control study, environmental information was collected from all of the cases and controls, while genetic information was only collected from cases. For this case-control study with incomplete data, a suitable parameterized log-linear model could simultaneously and efficiently estimate the main effect of environment and gene-environment interaction, whereas the logistic model could not.


CONCLUSIONS
For a partial case-control study, log-linear model could estimate not only the main effect of environment but also gene-environment interaction. If genotype and exposure were independent, estimators from partial case-control were as precisely as those from complete-data case-control studies.
Bai
Jian-ling
JL
Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 210029, China.
Xun
Peng-cheng
PC
Zhao
Yang
Y
Yu
Hao
H
Shen
Hong-bing
HB
Wei
Qing-yi
QY
Chen
Feng
F
D016022:Case-Control Studies; D004777:Environment; D005838:Genotype; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D015233:Models, Statistical; D015203:Reproducibility of Results