American Journal of Epidemiology Vol. 154, No. 3 : 259-263
Copyright © 2001 by The Johns Hopkins University School of Hygiene and Public Health
ORIGINAL CONTRIBUTIONS |
New Estimator of the Genotype Risk Ratio for Use in Case-Parental Control Studies
1 Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA.
2 Department of Mathematics, University of Southern California, Los Angeles, CA.
3 National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA.
Estimation of the genotype risk ratio can be an important part of studying the role of genetics in disease causation. For example, one might estimate risk among persons with genotype DD compared with risk among those with genotype Dd, where the candidate locus has alleles D and d, with D representing the disease susceptibility allele. In this paper, the authors propose a modified method of analysis for case-parental control studies that can improve efficiency. They show how investigators can use information from families in which both parents are observed to improve the estimator created by Sun et al., which applies when only one parent and an affected offspring have been observed. Since this information is not used by the conditional approach of Schaid and Sommer, the authors' approach allows for more complete use of available information, leading to a smaller mean squared error of the genotype risk ratio estimators. The authors also suggest a way to combine estimates from families in which one parent and one offspring are observed and estimates from families in which both parents and one offspring are observed.
case-control studies; epidemiologic methods; genetics; genotype; odds ratio
Abbreviations: GAW, Genetic Analysis Workshop.