Stats #77: Bayesian tools for planning and monitoring accrual rates in clinical trials

Content: This training class will discuss some Bayesian models for accrual (how rapidly patients volunteers for your research study).

Teaching strategies: Didactic lectures and small group exercises.

Abstract: Too many researchers overpromise and undeliver on the planned sample size and the planned completion date of their research. This leads to serious delays in the research and inadequate precision and power when the research is completed. Researchers need tools that will let them plan the pattern of patient accrual in their studies. These tools will also let the researchers carefully monitor the progress of their studies and let them take action quickly if accrual rates are suffering.

Objectives: In this seminar, you will learn how to:

• define problems associated with slipped deadlines and sample size shortfalls,
• describe a simple Bayesian model for patient accrual, and
• use this model to predict the planned duration of the clinical trial.

Notes: There are no pre-requisites for this seminar. This class does not qualify for IRB Education Credits (IRBECs).

Contents:

• Where can you find this handout?
• Slipped deadlines and sample size shortfalls in a random sample of research studies
• Why does a Bayesian approach make sense for monitoring accrual?
• A simple Bayesian model for exponential accrual times
• Case study of accrual in a clinical trial
• Monitoring refusals and exclusions in a clinical trial

Where can you find this handout?

This handout and the handouts that I use for all of my seminars and training classes are a compilation of individual web pages at www.childrensmercy.org/stats. I use the "Include Page" feature of Microsoft FrontPage to combine these into a single page. You can always find the most recent version of this compilation by going to the web address listed at the bottom of this page. Links for the handouts for other seminars and classes appear at www.childrensmercy.org/stats/training.asp.

Why don't I use PowerPoint?

I stopped using PowerPoint for my presentations in the mid 1990's. This was based on Edward Tufte's advice that presenting information in a paper handout is more effective than presenting the information on a projected screen. I found this to be excellent guidance. I enjoy talking when I don't have to wrestle with a laptop computer. I look at my audience more and interact with them better. I elaborate on this in greater detail at www.childrensmercy.org/stats/weblog2004/powerpoint.asp.