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Confidence intervals that match Fisher's exact or Blaker's exact tests
1Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892-7609, USA. mfay@niaid.nih.gov
Biostatistics (Oxford, England)
|December 2, 2009
Summary
Fisher's exact test and confidence intervals (CI) can conflict. This study introduces a "matching" interval for accurate inference from 2x2 tables, improving statistical analysis.
Area of Science:
- Statistics
- Biostatistics
- Data Analysis
Background:
- Fisher's exact test is common for 2x2 tables.
- Standard exact confidence intervals (CI) may conflict with test results.
- Existing methods can yield non-interval confidence sets.
Purpose of the Study:
- To address conflicting inferences between Fisher's exact test and exact CIs.
- To define and implement a "matching" interval for improved accuracy.
- To provide an R package for practical application.
Main Methods:
- Inverting one-sided and two-sided Fisher's exact tests.
- Defining a "matching" interval based on Blaker's (2000) work.
- Developing the R package exact2x2.
Main Results:
- Identified discrepancies between standard exact CIs and Fisher's exact test.
- Proposed a "matching" interval that contains the confidence set.
- The exact2x2 package implements three exact tests with matching intervals.
Conclusions:
- The "matching" interval provides a more consistent inference for 2x2 tables.
- The exact2x2 R package facilitates accurate statistical analysis.
- Improved methods enhance the reliability of odds ratio estimation.
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