University of Michigan Center for Statistical 


CaTS Tutorial


Brief Introduction

CaTS is an interactive power calculator for genetic association studies, with features that facilitate the design of two-stage genetic association studies.

Use the sliders and input boxes in the top half of the CaTS dialog to setup your study design and disease model parameters, and then select one of the tabs at the bottom of the screen to get estimated power, recommended thresholds for two stage analysis, and the fitted penetrances for each genotype.

In this tutorial, you will find examplar power calculations for two simple studies, examples of how an optimal design can be found and specific recommendations on how you should analyze data collected in a two-stage study:

Part 1 - Examplar Genome Wide Association Study
Part 2 - Examplar Candidate Gene Study
Part 3 - Finding Optimal Designs
Part 4 - Analyzing Data from Two-Stage Studies

We hope that you find this tutorial helpful, and that you will find CaTS useful and easy to use. For more details about the how power is calculated and thresholds determined, please see Skol et al. (2006). More detail about the output generated by CaTS and the user inputs can be found in the Reference section.


University of Michigan | School of Public Health | Abecasis Lab