Bivariate multilevel determinants for high risk adult mortality areas using an ecological framework, South Africa, 2007.

iRobust logistic regression for categorical variables and linear regression for comparison of means were employed. Note these formulations were used in place of standard χ2 and t- tests respectively to allow for clustering on the unit of analysis (quaternary level) and thus correctly adjust the standard errors (robust) and not erroneously overestimate significance.