ABSTRACT
As powerful personal computers and graphical user-interface (GUI) statistical software packages have become available and readily affordable in the last decade, complex statistical methods such as multivariable regression become more and more frequently used in medicine and epidemiology, despite involving complex numerical calculations. For instance, to obtain the regression coef‰cients for a multiple linear regression model with ‰ve covariates, one needs to invert a 5 × 5 matrix, which is very complex and might take days to do by hand. With the power of computers, it now only takes a few seconds to perform these calculations, and all the information relevant (or irrelevant) to the research questions can be shown on the computer screen.
