On the consequences of overstratification

It is common, in particular in observational studies in epidemiology, to impose stratification to adjust for possible effects of age and other variables on the binary outcome of interest. Overstratification may lower the precision of the estimated effects of interest. Understratification risks bias....

Full description

Saved in:
Bibliographic Details
Published in:Biometrika 2008-12, Vol.95 (4), p.992-996
Main Authors: De Stavola, B. L., Cox, D. R.
Format: Article
Language:English
Subjects:
Applications
Approximation
Bias
Binomial distribution
Biology, psychology, social sciences
Case control studies
Conditional likelihood
Confounder
Covariance
Efficiency loss
Epidemiology
Exact sciences and technology
Expected values
Fisher information
General topics
Information
Logistic model: Matched pairs
Logistics
Manifolds and cell complexes
Mathematics
Medical sciences
Miscellanea
Poisson distribution
Probability and statistics
Random variables
Sciences and techniques of general use
Standard error
Statistics
Studies
Topology. Manifolds and cell complexes. Global analysis and analysis on manifolds
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:It is common, in particular in observational studies in epidemiology, to impose stratification to adjust for possible effects of age and other variables on the binary outcome of interest. Overstratification may lower the precision of the estimated effects of interest. Understratification risks bias. These issues are studied analytically. Asymptotic results show that loss of efficiency depends on the true effect and on a measure of the average imbalance across strata between exposed and unexposed individuals. Bias depends on the correlation between stratum-specific size imbalances and event rates in the unexposed. Approximate results are also given. An example is used.
ISSN:0006-3444
1464-3510
DOI:10.1093/biomet/asn039