Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (33)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by GREENLAND, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by GREENLAND, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

American Journal of Epidemiology Vol. 128, No. 1: 231-237
Copyright © 1988 by The Johns Hopkins University School of Hygiene and Public Health

research-article

ON SAMPLE-SIZE AND POWER CALCULATIONS FOR STUDIES USING CONFIDENCE INTERVALS

SANDER GREENLAND

Division of Epidemiology, UCLA School of Public Health Los Angeles, CA 90024

A recent trend in epidemiologic analysis has been away from significance tests and toward confidence intervals. In accord with this trend, several authors have proposed the use of expected confidence intervals in the design of epidemiologic studies. This paper discusses how expected confidence intervals, if not properly centered, can be misleading indicators of the discriminatory power of a study. To rectify such problems, the study must be designed so that the confidence interval has a high probability of not containing at least one plausible but incorrect parameter value. To achieve this end, conventional formulas for power and sample size may be used. Expected intervals, if properly centered, can be used to design uniformly powerful studies but will yield sample-size requirements far in excess of previously proposed methods.

epidemiologic methods; statistics


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Tobacco ControlHome page
M Bobak, A Gilmore, M McKee, R Rose, and M Marmot
Changes in smoking prevalence in Russia, 1996-2004.
Tob. Control, April 1, 2006; 15(2): 131 - 135.
[Abstract] [Full Text] [PDF]

Home page
 Am J EpidemiolHome page
C. K. Porter, S. D. Putnam, K. L. Hunting, and M. R. Riddle
The Effect of Trihalomethane and Haloacetic Acid Exposure on Fetal Growth in a Maryland County
Am. J. Epidemiol., August 15, 2005; 162(4): 334 - 344.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
G. L. Grunkemeier, Y. X. Wu, and A. P. Furnary
Cumulative sum techniques for assessing surgical results
Ann. Thorac. Surg., September 1, 2003; 76(3): 663 - 667.
[Full Text] [PDF]

Home page
 Educational and Psychological MeasurementHome page
G. Cumming and S. Finch
A Primer on the Understanding, Use, and Calculation of Confidence Intervals that are Based on Central and Noncentral Distributions
Educational and Psychological Measurement, August 1, 2001; 61(4): 532 - 574.
[Abstract] [PDF]

Home page
 Stat Methods Med ResHome page
P. J. Wickramaratne
Sample size determination in epidemiologic studies
Statistical Methods in Medical Research, December 1, 1995; 4(4): 311 - 337.
[Abstract] [PDF]

Home page
 Stat Methods Med ResHome page
T. R. Holford and C. Stack
Study design for epidemiologic studies with measurement error
Statistical Methods in Medical Research, December 1, 1995; 4(4): 339 - 358.
[Abstract] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.