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A Two‐Stage Approach to the Correction of Ascertainment Bias in Complex Genetic Studies Involving Variance Components
Author(s) -
Bowden J.,
Thompson J. R.,
Burton P. R.
Publication year - 2007
Publication title -
annals of human genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 77
eISSN - 1469-1809
pISSN - 0003-4800
DOI - 10.1111/j.1469-1809.2006.00307.x
Subject(s) - variance (accounting) , population , statistics , stage (stratigraphy) , econometrics , computer science , sample (material) , sampling bias , process (computing) , mathematics , sample size determination , biology , demography , paleontology , chemistry , accounting , chromatography , sociology , business , operating system
Summary Correction for ascertainment bias is a vital part of the analysis of genetic epidemiology studies that needs to be undertaken whenever subjects are not recruited at random. Adjustment often requires extensive numerical integration, which can be very slow or even computationally infeasible, especially if the model includes many fixed and random effects. In this paper we propose a two‐stage method for ascertainment bias correction. In the first stage we estimate parameters that pertain to the ascertained population, that is the population that would be selected into the sample if the ascertainment criterion were applied to everyone. In the second stage we convert the estimates for the ascertained population into general population parameter estimates. We illustrate the method with simulations based on a simple model and then describe how the method can be used with complex models. The two‐stage approach avoids some of the integration required in direct adjustment, hence speeding up the process of model fitting.