Summer 2007 Workshop
Held on June 14, 2007 at the
Skokie Doubletree Hotel & Conference Center.
The 23rd Annual Summer Workshop
of the Northeastern Illinois Chapter of the American Statistical Association
was given on the topic of:
Analysis for Study Planning
Dr. Ralph O'Brien, The Cleveland Clinic Foundation
Performing a conscientious sample-size
analysis is often a cornerstone of effective study planning, because the
research team (including the statistician) must delineate, critique, and
tighten the specific aims, research questions, design, measurements, and
analysis plans. This highly-interactive course uses realistic case studies
to cover the scientific/statistical principles and general consulting
pragmatics associated with such work. Issues of statistical science are
stressed far more than mathematical and computational underpinnings.
Although all analyses covered are traditional (frequentist), we show how a
simple Bayesian notion ("The March of Science") helps to clarify and shape
the planning process for investigators, statisticians, and peer reviewers.
All examples employ SAS9 procedures and freeware, but participants also see
how the same calculations are performed using PASS and nQuery Advisor along
with a simple Excel spreadsheet developed/distributed by the instructor.
Much of this course is based on O'Brien RG, Castelloe JM (2007),
“Sample-Size Analysis for Traditional Hypothesis Testing: Concepts and
Issues,” in Dmitrienko A, Chuang-Stein C, D’Agostino R (Ed.),
Pharmaceutical Statistics Using SAS: A Practical Guide, Cary, NC: SAS
O’Brien is currently a professor in the Department of Quantitative Health
Sciences and the Lerner College of Medicine at the Cleveland Clinic
Foundation. His career in statistics is broad, beginning in behavioral
statistics (Psychology Dept., University of Virginia, 1975-82), then moving
more to the mainstream (Statistics Dept., University of Tennessee, 1982-89),
and then to biomedicine (Division of Biostatistics, Department of
Statistics, University of Florida, 1989-94), where Dr. O’Brien was Director
of Biostatistics. He is the creator of “O’Brien’s test” for variance
differences, performed by both SAS®
(PROC GLM) and JMP®.
However, his main contributions have been in promoting more effective
sample-size analyses for study planning. His freeware module, UnifyPow.sas,
is used all over the world, and he now consults intensively with SAS
personnel who are developing PROCs POWER and GLMPOWER and other such tools.
He has given over 25 workshops on sample-size analysis to over 2000 people,
and his continuing education courses at annual Joint Statistical Meetings
earned him an “Excellence-in-CE” award from the American Statistical