In the past decade, many statistical methods have been proposed for the analysis of case–control genetic data with an emphasis on haplotype-based disease association studies. Most of the methodology has concentrated on the estimation of genetic (haplotype) main effects. Most methods accounted...

Through the use of user-written programs, primarily mim (Carlin, Galati, and Royston, 2008), Stata users can analyze multiply imputed (MI) datasets. Among other capabilities, mim allows the user to estimate a range of regression models and to perform a multi-parameter hypothesis tests after...

Analyzing survey data is different from analyzing data generated by experiments in several important ways. These differences will be discussed using the NHANES III adult data set as an example. Topics will include specifying the survey elements, analysis of subpopulations, model diagnostics and...

Stata is a very good tool to analyze survey data. It is able to consider many important aspects of complex survey design and the availability of alternative variance estimation methods. Through the use of matrix and macro language it also allows the user to store and manage output results...

This presentation focuses on predicted probabilities for multilevel models for dichotomous or ordinal responses. In a three-level model, for instance with patients nested in doctors nested in hospitals, predictions for patients could be for new or existing doctors and, in the latter case, for...

The Statistical Consulting Group provides a variety of resources to Stata users on campus, from walk-in and email consulting to an extensive website on materials related to Stata. This presentation will explain how the group offers such services and will discuss the three major components of the...

While Stata, of course, comes with a serviceable set of I/O commands, I have found room for improvement. I will present a set of user-written commands for using, saving, appending, and merging. Highlights include wildcards in file paths, drastically reducing the amount that needs to be typed;...

Stata’s xtmixed command can be used to fit mixed models, models that contain both fixed and random effects. The fixed effects are merely the coefficients from a standard linear regression. The random effects are not directly estimated but summarized by their variance components, which are...

Three approaches to understanding 3-way anova interactions will be presented: 1) a conceptual approach, 2) an anova approach and 3) a regression approach using dummy coding. The three approaches are illustrated through the use of a synthetic dataset with a significant 3-way interaction.

I will present a selection of user-written Mata functions that serve to streamline the process of writing other Mata functions, and I will demonstrate what makes them handy. I will present debugging/programming functions for the following: dropping and re-creating one or a few functions without...