Journal article
Power Estimation for Multireader ROC Methods: An Updated and Unified Approach
Academic radiology, Vol.18(2), pp.129-142
02/01/2011
DOI: 10.1016/j.acra.2010.09.007
PMCID: PMC3053069
PMID: 21232681
Abstract
Rationale and Objectives: We describe a step-by-step procedure for estimating power and sample size for planned multireader receiver operating characteristic (ROC) studies that will be analyzed using either the Dorfman-Berbaum-Metz (DBM) or Obuchowski-Rockette (OR) method. This procedure updates previous approaches by incorporating recent methodological developments and unifies the approaches by allowing inputs to be conjectured parameter values or outputs from either a DBM or OR pilot-study analysis.
Materials and Methods: Power computations are described in a step-by-step procedure and the theoretical basis for the procedure is described. Updates include using the currently recommended denominator degrees of freedom, accounting for different pilot and planned study normal-to-abnormal case ratios, and a new method for computing the OR test-by-reader variance component.
Results: Using a real dataset we illustrate how to compute the power for two planned studies, one having the same normal-to-abnormal case ratio as the pilot study and the other having a different ratio. In a simulation study, we show that the proposed procedure gives mean power estimates close to the true power.
Conclusions: Application of the updated procedure is straightforward. It is important that pilot data be comparable to the planned study with respect to the modalities, reader expertise, and case selection. Variability of the power estimates warrants further investigation.
Details
- Title: Subtitle
- Power Estimation for Multireader ROC Methods: An Updated and Unified Approach
- Creators
- Stephen L. Hillis - Center for Research in the Implementation of Innovative Strategies in Practice (CRIISP), Iowa City VA Medical Center (152), 601 Highway 6 West, Iowa City, IA 52246-2208Nancy A. Obuchowski - Cleveland ClinicKevin S. Berbaum - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Academic radiology, Vol.18(2), pp.129-142
- DOI
- 10.1016/j.acra.2010.09.007
- PMID
- 21232681
- PMCID
- PMC3053069
- NLM abbreviation
- Acad Radiol
- ISSN
- 1076-6332
- eISSN
- 1878-4046
- Publisher
- Elsevier
- Number of pages
- 14
- Grant note
- R01EB000863 / National Institutes of Health; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA R01EB000863 / NATIONAL INSTITUTE OF BIOMEDICAL IMAGING AND BIOENGINEERING; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of Biomedical Imaging & Bioengineering (NIBIB)
- Language
- English
- Date published
- 02/01/2011
- Academic Unit
- Radiology; Biostatistics
- Record Identifier
- 9984318696502771
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