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RJafroc (version 1.3.2)

StSignificanceTesting: Perform DBM or OR significance testing

Description

Performs Dorfman-Berbaum-Metz (DBM) or Obuchowski-Rockette (OR) significance testing (with Hillis' improvements), for specified dataset; significance testing refers to analysis designed to assign a P-value, and other statistics, for rejecting the null hypothesis (NH) that the reader-averaged figure of merit (FOM) difference between treatments is zero. The results of the analysis are better visualized in the text or Excel-formatted files produced by UtilOutputReport.

Usage

StSignificanceTesting(
  dataset,
  FOM,
  FPFValue = 0.2,
  alpha = 0.05,
  method = "DBMH",
  covEstMethod = "Jackknife",
  nBoots = 200,
  option = "ALL",
  tempOrgCode = FALSE
)

Arguments

dataset

The dataset to be analyzed, see RJafroc-package. Must have two or more treatments and two or more readers.

FOM

The figure of merit, see UtilFigureOfMerit

FPFValue

Only needed for LROC data and FOM = "PCL" or "ALROC"; where to evaluate a partial curve based figure of merit. The default is 0.2.

alpha

The significance level of the test of the null hypothesis that all treatment effects are zero; the default is 0.05

method

The significance testing method to be used. There are two options: "DBMH" (the default) or "ORH", representing the Dorfman-Berbaum-Metz and the Obuchowski-Rockette significance testing methods, respectively.

covEstMethod

The covariance matrix estimation method in ORH analysis (for method = "DBMH" the jackknife is always used).

  • "Jackknife", the default,

  • "Bootstrap", in which case nBoots (above) is relevant

  • "DeLong"; requires FOM = "Wilcoxon", otherwise an error results.

nBoots

The number of bootstraps (defaults to 200), relevant only if covEstMethod = "Bootstrap" and method = "ORH"

option

Determines which factors are regarded as random vs. fixed:

  • "RRRC" = random-reader random case,

  • "FRRC" = fixed-reader random case,

  • "RRFC" = random-reader fixed case,

  • "ALL" = outputs the results of "RRRC", "FRRC" and "RRFC" analyses

tempOrgCode,

default FALSE; if TRUE, then code from version 0.0.1 of RJafroc is used (see RJafroc_0.0.1.tar). This is intended to check against errors that crept in subsequent to the original version as I attempted to improve the organization of the code and the output. As implicit in the name of this temporary flag, it will eventually be removed.

Value

For method = "DBMH" the returned list has 15 members:

fomArray

Figure of merit array: see return of UtilFigureOfMerit

anovaY

ANOVA table of the pseudovalues, over all treatments

anovaYi

ANOVA table of the pseudovalues, for each treatment

varComp

The variance components of the DBM pseudovalue mode; 6 values, in the following order: varR, varC, varTR, varTC, varRC and varErr

FTestStatsRRRC

Results of the F-test for RRRC random reader random case analysis; contains the following items: fRRRC - the value of the F-statistic, ndfRRRC - the numerator degrees of freedom, ddfRRRC - the denominator degrees of freedom and pRRRC - the pvalue

ciDiffTrtRRRC

For RRRC analysis, the confidence intervals and related statistics for the FOM differences between pairs of treatments

ciAvgRdrEachTrtRRRC

For RRRC analysis, the confidence intervals and related test statistics for rdr. avg. FOM in each treatment

FTestStatsFRRC

As for FTestStatsRRRC except that this is for fixed-reader random-case (FRRC) analysis

ciDiffTrtFRRC

For FRRC analysis, the confidence intervals and related test statistics for the FOM differences between pairs of treatments

ciAvgRdrEachTrtFRRC

For FRRC analysis, the confidence intervals and related tests for rdr. avg. FOM in each treatment

msAnovaEachRdrFRRC

The mean squares table of the ANOVA of the pseudovalues for each reader (based on data for the specified reader)

ciDiffTrtEachRdrFRRC

The confidence intervals and related tests of the FOM differences between pairs of treatments for each reader

FTestStatsRRFC

As for FTestStatsRRRC except that this is for random-reader fixed-case (RRFC) analysis

ciDiffTrtRRFC

For RRFC analysis, the confidence intervals and related test statistics for the FOM differences between pairs of treatments

ciAvgRdrEachTrtRRFC

For RRFC analysis, the confidence intervals and related tests for reader averaged FOM in each treatment

For method = "ORH" the return list has 14 members:

fomArray

Figure of merit array: see return of UtilFigureOfMerit

meanSquares

List with 3 members: msT, msR, msTR

varComp

The variance components of the OR figure of merit model; 6 values, listed in the following order: varR, varTR, cov1, cov2, cov3 and var

FTestStatsRRRC

Results of the F-test for RRRC random reader random case analysis; contains the following items: fRRRC - the value of the F-statistic, ndfRRRC - the numerator degrees of freedom, ddfRRRC - the denominator degrees of freedom and pRRRC - the pvalue

ciDiffTrtRRRC

Same as in DBMH method

ciAvgRdrEachTrtRRRC

Same as in DBMH method

FTestStatsFRRC

Same as FTestStatsRRRC, but now treating reader as a fixed effect

ciDiffTrtFRRC

Same as in DBMH method

ciAvgRdrEachTrtFRRC

Same as in DBMH method

ciDiffTrtEachRdrFRRC

Same as in DBMH method

varCovEachRdr

Var and Cov1 estimates for each reader

FTestStatsRRFC

Same as FTestStatsRRRC, but now treating case as a fixed effect

ciDiffTrtRRFC

Same as in DBMH method

ciAvgRdrEachTrtRRFC

Same as in DBMH method

References

Dorfman DD, Berbaum KS, Metz CE (1992) ROC characteristic rating analysis: Generalization to the Population of Readers and Patients with the Jackknife method, Invest. Radiol. 27, 723-731.

Obuchowski NA, Rockette HE (1995) Hypothesis Testing of the Diagnostic Accuracy for Multiple Diagnostic Tests: An ANOVA Approach with Dependent Observations, Communications in Statistics: Simulation and Computation 24, 285-308.

Hillis SL (2014) A marginal-mean ANOVA approach for analyzing multireader multicase radiological imaging data, Statistics in medicine 33, 330-360.

Chakraborty DP (2017) Observer Performance Methods for Diagnostic Imaging - Foundations, Modeling, and Applications with R-Based Examples, CRC Press, Boca Raton, FL. https://www.crcpress.com/Observer-Performance-Methods-for-Diagnostic-Imaging-Foundations-Modeling/Chakraborty/p/book/9781482214840

Examples

Run this code
# NOT RUN {
StSignificanceTesting(dataset02,FOM = "Wilcoxon", method = "DBMH") 
StSignificanceTesting(dataset02,FOM = "Wilcoxon", method = "ORH")

# }
# NOT RUN {
StSignificanceTesting(dataset05, FOM = "wAFROC")
StSignificanceTesting(dataset05, FOM = "HrAuc", method = "DBMH") 
StSignificanceTesting(dataset05, FOM = "SongA1", method = "DBMH") 
StSignificanceTesting(dataset05, FOM = "SongA2", method = "DBMH") 
StSignificanceTesting(dataset05, FOM = "FOM_wAFROC1", method = "DBMH")
StSignificanceTesting(dataset05, FOM = "FOM_AFROC1", method = "DBMH")
StSignificanceTesting(dataset05, FOM = "FOM_AFROC", method = "DBMH")
# }
# NOT RUN {

# }

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