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Comparison of quantitative diagnostic tests: Type I error, power, and sample size
Author(s) -
Linnet Kristian
Publication year - 1987
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.4780060207
Subject(s) - statistics , type i and type ii errors , sample size determination , statistical power , sensitivity (control systems) , mathematics , gaussian , limit (mathematics) , normal distribution , range (aeronautics) , sampling (signal processing) , computer science , physics , mathematical analysis , materials science , quantum mechanics , electronic engineering , engineering , composite material , filter (signal processing) , computer vision
For a quantitative laboratory test the 0.975 fractile of the distribution of reference values is commonly used as a discrimination limit, and the sensitivity of the test is the proportion of diseased subjects with values exceeding this limit. A comparison of the estimates of sensitivity between two tests without taking into account the sampling variation of the discrimination limits can increase the type I error to about seven times the nominal value of 0.05. Correct statistical procedures are considered, and the power and required sample size are studied for Gaussian and log‐Gaussian distributions of diagnostic test values. The results may be useful for the planning phase of studies to evaluate quantitative diagnostic tests.