sesp.exactbinom: Exact Binomial Test for Differences in Sensitivity and...

Description Usage Arguments Details Value References See Also Examples

Description

Performs an exact binomial test for differences in sensitivity and specificity of two binary diagnostic tests in a paired study design.

Usage

1

Arguments

tab

An object of class tab.paired.

Details

The function performs a standard exact binomial test.

An exact binomial test is recommended when the number of patients with differing results for test 1 and test 2 (discordant pairs) is small, i.e. <20 (Zhou et al., 2011).

Value

A list containing:

sensitivity

A list containing test1 (sensitivity of test 1), test2 (specificity of test 2), diff (the difference in sensitivity, computed as test2 - test1) and the corresponding p.value.

specificity

A list containing test1 (specificity of test 1), test2 (specificity of test 2), diff (the difference in specificity, computed as test2 - test1) and the corresponding p.value.

method

The name of the method used to compare sensitivity and specificity, here “exactbinom”.

References

Zhou, X., Obuchowski, N., and McClish, D. (2011). Statistical Methods in Diagnostic Medicine. Wiley Series in Probability and Statistics. John Wiley & Sons, Hoboken, New Jersey, 2nd edition.

See Also

sesp.mcnemar and tab.paired.

Examples

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data(Paired1) # Hypothetical study data
ftable(Paired1)
paired.layout <- tab.paired(d=d, y1=y1, y2=y2, data=Paired1)
paired.layout 
exact.results <- sesp.exactbinom(paired.layout)
str(exact.results)
exact.results
exact.results$sensitivity["p.value"]

Example output

Loading required package: gee
Loading required package: PropCIs
     y2   0   1
d y1           
0 0     155  22
  1      53  31
1 0      32  22
  1      78 319
Two binary diagnostic tests (paired design)

Test1: 'y1'
Test2: 'y2'

Diseased:
           Test1 pos. Test1 neg. Total
Test2 pos.        319         22   341
Test2 neg.         78         32   110
Total             397         54   451

Non-diseased:
           Test1 pos. Test1 neg. Total
Test2 pos.         31         22    53
Test2 neg.         53        155   208
Total              84        177   261

List of 3
 $ sensitivity:List of 4
  ..$ test1  : num 0.88
  ..$ test2  : num 0.756
  ..$ diff   : num -0.124
  ..$ p.value: num 1.59e-08
 $ specificity:List of 4
  ..$ test1  : num 0.678
  ..$ test2  : num 0.797
  ..$ diff   : num 0.119
  ..$ p.value: num 0.00045
 $ method     : chr "exactbinom"
$sensitivity
$sensitivity$test1
[1] 0.8802661

$sensitivity$test2
[1] 0.7560976

$sensitivity$diff
[1] -0.1241685

$sensitivity$p.value
[1] 1.590533e-08


$specificity
$specificity$test1
[1] 0.6781609

$specificity$test2
[1] 0.7969349

$specificity$diff
[1] 0.1187739

$specificity$p.value
[1] 0.000449648


$method
[1] "exactbinom"

$p.value
[1] 1.590533e-08

DTComPair documentation built on May 2, 2019, 6:53 a.m.