It should also be emphasized that prior information about the regulatory network can be easily incorporated into the algorithm by fixing known coefficients of the independence matrices used at each iteration.
For African-Americans and Caucasians single locus genotypic tests of association (additive model) were performed with generalized estimating equations (GEE) using the independence correlation matrix implemented in SAS PROC GENMODD) statistical software version 9.1 (SAS Institute, Cary, NC).
Mantel test results, reported below, overcome the non-independence of matrix observations, and allowed us to accurately assess the relationship between geography and molecular evolution.
We employ the "independence working matrices" assumption of Prentice and Zhao [ 15], approximating the elements of V * based on a simplifying assumption of independence and normality among the elements of Y.
Finally, in the case of independence, the matrices with covariance do not always have lower relative error, but this is expected, because the true covariance is null in this special case.
We used an independence working correlation matrix to take into account clustering within households and as a result of using the GEE approach the correlation between the number of contacts from the same participant over different age-categories is also taken into account.
Each family was treated as a cluster, with independence working correlation matrix used in the robust variance estimator.
All the factors were significant in the logistic regression by GEE, with an independence working correlation matrix (P < 0.05) (Table 3).
We compared the relative gain in sensitivity between lesions using a marginal regression approach involving a log-link function and an independence working covariance matrix by applying a generalised estimating equation (Sullivan Pepe and Alonzo, 2001).
To investigate the effect of weight loss on the logarithm of each hormone, we fit separate marginal regression models using generalized estimating equations with an independence working correlation matrix to estimate robust standard errors that accounted for multiple measurements over time within a subject.
