Estimating the relative recurrence risk ratio using a global cross-ratio model

✍ Scribed by Chris Wallace; David Clayton

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 141 KB
• Volume: 25
• Category: Article
• ISSN: 0741-0395
• DOI: 10.1002/gepi.10270

✦ Synopsis

Abstract

The relative recurrence risk ratio λ~R~ (and particularly the sibling recurrence risk ratio, λ~S~ ) is often of interest to those wanting to quantify the genetic contribution towards risk of disease or to discriminate between different genetic models. However, estimating λ~R~ for complex diseases for which genetic and environmental risk factors are both involved is not straightforward. Ignoring environmental factors may lead to inflated estimates of λ~R~. We present a marginal model which uses a copula function to model the association in cumulative incidence rates between pairs of relatives. This model is applicable to present‐state data and allows estimation of risk of disease in a pair of relatives (and hence λ~R~), given measured environmental covariates. We apply the model to leprosy among sibling pairs from the Karonga district, Malawi. If risk factors are ignored, the apparent λ~S~ in this population is over 3. Accounting for known nongenetic risk factors reduces it to just under 2. Genet Epidemiol 25:293–302, 2003. © 2003 Wiley‐Liss, Inc.