The Taylor series linearization method (Wolter, 1985) was implemented in SAS 9.3 (SAS Institute Inc., 2011) to adjust for the weighting, including non-response and post-stratification weighting, and geographic clustering of the WMH sample. Multivariate significance was evaluated using design-based Wald χ2 tests. Statistical significance was evaluated with 0.05-level two-sided tests.
