Group sequential designs

Home / Products / Features / Group sequential designs

Group sequential designs New

Why wait until you finish collecting data to analyze the results of your clinical trial? Group sequential designs (GSDs) allow you to preplan interim analyses of clinical-trial data while controlling the familywise error rate. If interim results are conclusive, you can stop the trial early for efficacy or futility, saving resources and sparing participants from receiving inferior treatments. Use Stata's gsdesign commands or interactive Control Panel to calculate efficacy- and futility-stopping boundaries, compute sample sizes for interim analyses, compare GSDs with equivalently powered fixed studies, and graph the stopping boundaries for your trial.

Learn about Group sequential designs.

Watch Group sequential designs.

GSD methods

One-sample mean test
Two-sample means test
One-sample proportion test
Two-sample proportions test
Log-rank test of survivor functions
User-defined test

Stopping boundaries

Classical O'Brien–Fleming bounds
Classical Pocock bounds
Classical Wang–Tsiatis bounds
Error-spending O'Brien–Fleming-style bounds
Error-spending Pocock-style bounds
Error-spending Kim–DeMets bounds
Error-spending Hwang–Shih–de Cani bounds

Stopping for

Efficacy
Futility
Both efficacy and futility

Futility boundaries

Binding
Nonbinding

Control Panel interface

Select analysis type from descriptive summaries
Specify analysis interactively
Automated tables and graphs
Customizable tables and graphs
Command interface

Graph boundaries

Show critical values at each look
Compare with fixed-study critical values
Customizable

Interim analyses

Evenly spaced
Unevenly spaced at user-specified increments

Additional resources

Adaptive Designs: Group Sequential Trials Reference Manual

Also see power and sample-size analysis for fixed-sample designs.

We use cookies

We use cookies to ensure that we give you the best experience on our website—to enhance site navigation, to analyze usage, and to assist in our marketing efforts. By continuing to use our site, you consent to the storing of cookies on your device and agree to delivery of content, including web fonts and JavaScript, from third party web services.

Cookie Settings

Last updated: 16 November 2022

StataCorp LLC (StataCorp) strives to provide our users with exceptional products and services. To do so, we must collect personal information from you. This information is necessary to conduct business with our existing and potential customers. We collect and use this information only where we may legally do so. This policy explains what personal information we collect, how we use it, and what rights you have to that information.

Advertising and performance cookies

This website uses cookies to provide you with a better user experience. A cookie is a small piece of data our website stores on a site visitor's hard drive and accesses each time you visit so we can improve your access to our site, better understand how you use our site, and serve you content that may be of interest to you. For instance, we store a cookie when you log in to our shopping cart so that we can maintain your shopping cart should you not complete checkout. These cookies do not directly store your personal information, but they do support the ability to uniquely identify your internet browser and device.

Please note: Clearing your browser cookies at any time will undo preferences saved here. The option selected here will apply only to the device you are currently using.